chore: Release

Ready for publish
Update Ratatui
2025-12-26 00:11:49 +02:00 · 2024-08-09 11:52:31 +02:00 · 2024-08-09 11:51:56 +02:00 · 2024-08-09 02:17:01 +02:00 · 2024-08-09 01:27:31 +02:00 · 2024-08-09 01:16:45 +02:00
57 changed files with 995 additions and 895 deletions
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -23,7 +23,7 @@ jobs:
        with:
          globs: "exercises/**/*.md"
      - name: Run cargo fmt
-        run: cargo fmt --all -- --check
+        run: cargo fmt --all --check
  test:
    runs-on: ${{ matrix.os }}
    strategy:
@@ -33,7 +33,7 @@ jobs:
      - uses: actions/checkout@v4
      - uses: swatinem/rust-cache@v2
      - name: Run cargo test
-        run: cargo test
+        run: cargo test --workspace
  dev-check:
    runs-on: ubuntu-latest
    steps:
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,21 @@
+<a name="6.2.0"></a>
+
+## 6.2.0 (2024-08-09)
+
+### Added
+
+- Show a message before checking and running an exercise. This gives the user instant feedback and avoids confusion if the checks take too long.
+- Show a helpful error message when trying to install Rustlings with a Rust version lower than the minimum one that Rustlings supports.
+- Add a `README.md` file to the `solutions/` directory.
+- Allow initializing Rustlings in a Cargo workspace.
+- `dev check`: Check that all solutions are formatted with `rustfmt`.
+
+### Changed
+
+- Remove the state file and the solutions directory from the generated `.gitignore` file.
+- Run the final check of all exercises in parallel.
+- Small exercise improvements.
+
 <a name="6.1.0"></a>

 ## 6.1.0 (2024-07-10)
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -14,15 +14,6 @@ dependencies = [
 "zerocopy",
 ]

-[[package]]
-name = "aho-corasick"
-version = "1.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "allocator-api2"
 version = "0.2.18"
@@ -31,9 +22,9 @@ checksum = "5c6cb57a04249c6480766f7f7cef5467412af1490f8d1e243141daddada3264f"

 [[package]]
 name = "anstream"
-version = "0.6.14"
+version = "0.6.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "418c75fa768af9c03be99d17643f93f79bbba589895012a80e3452a19ddda15b"
+checksum = "64e15c1ab1f89faffbf04a634d5e1962e9074f2741eef6d97f3c4e322426d526"
 dependencies = [
 "anstyle",
 "anstyle-parse",
@@ -46,33 +37,33 @@ dependencies = [

 [[package]]
 name = "anstyle"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "038dfcf04a5feb68e9c60b21c9625a54c2c0616e79b72b0fd87075a056ae1d1b"
+checksum = "1bec1de6f59aedf83baf9ff929c98f2ad654b97c9510f4e70cf6f661d49fd5b1"

 [[package]]
 name = "anstyle-parse"
-version = "0.2.4"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c03a11a9034d92058ceb6ee011ce58af4a9bf61491aa7e1e59ecd24bd40d22d4"
+checksum = "eb47de1e80c2b463c735db5b217a0ddc39d612e7ac9e2e96a5aed1f57616c1cb"
 dependencies = [
 "utf8parse",
 ]

 [[package]]
 name = "anstyle-query"
-version = "1.1.0"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ad186efb764318d35165f1758e7dcef3b10628e26d41a44bc5550652e6804391"
+checksum = "6d36fc52c7f6c869915e99412912f22093507da8d9e942ceaf66fe4b7c14422a"
 dependencies = [
 "windows-sys 0.52.0",
 ]

 [[package]]
 name = "anstyle-wincon"
-version = "3.0.3"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61a38449feb7068f52bb06c12759005cf459ee52bb4adc1d5a7c4322d716fb19"
+checksum = "5bf74e1b6e971609db8ca7a9ce79fd5768ab6ae46441c572e46cf596f59e57f8"
 dependencies = [
 "anstyle",
 "windows-sys 0.52.0",
@@ -84,21 +75,6 @@ version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"

-[[package]]
-name = "assert_cmd"
-version = "2.0.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed72493ac66d5804837f480ab3766c72bdfab91a65e565fc54fa9e42db0073a8"
-dependencies = [
- "anstyle",
- "bstr",
- "doc-comment",
- "predicates",
- "predicates-core",
- "predicates-tree",
- "wait-timeout",
-]
-
 [[package]]
 name = "autocfg"
 version = "1.3.0"
@@ -117,17 +93,6 @@ version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"

-[[package]]
-name = "bstr"
-version = "1.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05efc5cfd9110c8416e471df0e96702d58690178e206e61b7173706673c93706"
-dependencies = [
- "memchr",
- "regex-automata",
- "serde",
-]
-
 [[package]]
 name = "cassowary"
 version = "0.3.0"
@@ -151,9 +116,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

 [[package]]
 name = "clap"
-version = "4.5.9"
+version = "4.5.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64acc1846d54c1fe936a78dc189c34e28d3f5afc348403f28ecf53660b9b8462"
+checksum = "c937d4061031a6d0c8da4b9a4f98a172fc2976dfb1c19213a9cf7d0d3c837e36"
 dependencies = [
 "clap_builder",
 "clap_derive",
@@ -161,9 +126,9 @@ dependencies = [

 [[package]]
 name = "clap_builder"
-version = "4.5.9"
+version = "4.5.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6fb8393d67ba2e7bfaf28a23458e4e2b543cc73a99595511eb207fdb8aede942"
+checksum = "85379ba512b21a328adf887e85f7742d12e96eb31f3ef077df4ffc26b506ffed"
 dependencies = [
 "anstream",
 "anstyle",
@@ -173,9 +138,9 @@ dependencies = [

 [[package]]
 name = "clap_derive"
-version = "4.5.8"
+version = "4.5.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2bac35c6dafb060fd4d275d9a4ffae97917c13a6327903a8be2153cd964f7085"
+checksum = "501d359d5f3dcaf6ecdeee48833ae73ec6e42723a1e52419c79abf9507eec0a0"
 dependencies = [
 "heck",
 "proc-macro2",
@@ -185,25 +150,26 @@ dependencies = [

 [[package]]
 name = "clap_lex"
-version = "0.7.1"
+version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b82cf0babdbd58558212896d1a4272303a57bdb245c2bf1147185fb45640e70"
+checksum = "1462739cb27611015575c0c11df5df7601141071f07518d56fcc1be504cbec97"

 [[package]]
 name = "colorchoice"
-version = "1.0.1"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b6a852b24ab71dffc585bcb46eaf7959d175cb865a7152e35b348d1b2960422"
+checksum = "d3fd119d74b830634cea2a0f58bbd0d54540518a14397557951e79340abc28c0"

 [[package]]
 name = "compact_str"
-version = "0.7.1"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f86b9c4c00838774a6d902ef931eff7470720c51d90c2e32cfe15dc304737b3f"
+checksum = "6050c3a16ddab2e412160b31f2c871015704239bca62f72f6e5f0be631d3f644"
 dependencies = [
 "castaway",
 "cfg-if",
 "itoa",
+ "rustversion",
 "ryu",
 "static_assertions",
 ]
@@ -225,15 +191,15 @@ checksum = "22ec99545bb0ed0ea7bb9b8e1e9122ea386ff8a48c0922e43f36d45ab09e0e80"

 [[package]]
 name = "crossterm"
-version = "0.27.0"
+version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f476fe445d41c9e991fd07515a6f463074b782242ccf4a5b7b1d1012e70824df"
+checksum = "829d955a0bb380ef178a640b91779e3987da38c9aea133b20614cfed8cdea9c6"
 dependencies = [
 "bitflags 2.6.0",
 "crossterm_winapi",
- "libc",
- "mio",
+ "mio 1.0.1",
 "parking_lot",
+ "rustix",
 "signal-hook",
 "signal-hook-mio",
 "winapi",
@@ -248,18 +214,6 @@ dependencies = [
 "winapi",
 ]

-[[package]]
-name = "difflib"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6184e33543162437515c2e2b48714794e37845ec9851711914eec9d308f6ebe8"
-
-[[package]]
-name = "doc-comment"
-version = "0.3.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fea41bba32d969b513997752735605054bc0dfa92b4c56bf1189f2e174be7a10"
-
 [[package]]
 name = "either"
 version = "1.13.0"
@@ -272,6 +226,22 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"

+[[package]]
+name = "errno"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "534c5cf6194dfab3db3242765c03bbe257cf92f22b38f6bc0c58d59108a820ba"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "fastrand"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9fc0510504f03c51ada170672ac806f1f105a88aa97a5281117e1ddc3368e51a"
+
 [[package]]
 name = "filetime"
 version = "0.2.23"
@@ -284,15 +254,6 @@ dependencies = [
 "windows-sys 0.52.0",
 ]

-[[package]]
-name = "float-cmp"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "98de4bbd547a563b716d8dfa9aad1cb19bfab00f4fa09a6a4ed21dbcf44ce9c4"
-dependencies = [
- "num-traits",
-]
-
 [[package]]
 name = "fsevent-sys"
 version = "4.1.0"
@@ -319,10 +280,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"

 [[package]]
-name = "indexmap"
-version = "2.2.6"
+name = "hermit-abi"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "168fb715dda47215e360912c096649d23d58bf392ac62f73919e831745e40f26"
+checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
+
+[[package]]
+name = "indexmap"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de3fc2e30ba82dd1b3911c8de1ffc143c74a914a14e99514d7637e3099df5ea0"
 dependencies = [
 "equivalent",
 "hashbrown",
@@ -349,10 +316,20 @@ dependencies = [
 ]

 [[package]]
-name = "is_terminal_polyfill"
-version = "1.70.0"
+name = "instability"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8478577c03552c21db0e2724ffb8986a5ce7af88107e6be5d2ee6e158c12800"
+checksum = "b23a0c8dfe501baac4adf6ebbfa6eddf8f0c07f56b058cc1288017e32397846c"
+dependencies = [
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"

 [[package]]
 name = "itertools"
@@ -395,6 +372,12 @@ version = "0.2.155"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"

+[[package]]
+name = "linux-raw-sys"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78b3ae25bc7c8c38cec158d1f2757ee79e9b3740fbc7ccf0e59e4b08d793fa89"
+
 [[package]]
 name = "lock_api"
 version = "0.4.12"
@@ -413,9 +396,9 @@ checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"

 [[package]]
 name = "lru"
-version = "0.12.3"
+version = "0.12.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3262e75e648fce39813cb56ac41f3c3e3f65217ebf3844d818d1f9398cfb0dc"
+checksum = "37ee39891760e7d94734f6f63fedc29a2e4a152f836120753a72503f09fcf904"
 dependencies = [
 "hashbrown",
 ]
@@ -439,10 +422,17 @@ dependencies = [
 ]

 [[package]]
-name = "normalize-line-endings"
-version = "0.3.0"
+name = "mio"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61807f77802ff30975e01f4f071c8ba10c022052f98b3294119f3e615d13e5be"
+checksum = "4569e456d394deccd22ce1c1913e6ea0e54519f577285001215d33557431afe4"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "log",
+ "wasi",
+ "windows-sys 0.52.0",
+]

 [[package]]
 name = "notify"
@@ -458,7 +448,7 @@ dependencies = [
 "kqueue",
 "libc",
 "log",
- "mio",
+ "mio 0.8.11",
 "walkdir",
 "windows-sys 0.48.0",
 ]
@@ -473,15 +463,6 @@ dependencies = [
 "notify",
 ]

-[[package]]
-name = "num-traits"
-version = "0.2.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
-dependencies = [
- "autocfg",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.19.0"
@@ -490,12 +471,12 @@ checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"

 [[package]]
 name = "os_pipe"
-version = "1.2.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29d73ba8daf8fac13b0501d1abeddcfe21ba7401ada61a819144b6c2a4f32209"
+checksum = "5ffd2b0a5634335b135d5728d84c5e0fd726954b87111f7506a61c502280d982"
 dependencies = [
 "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -516,7 +497,7 @@ checksum = "1e401f977ab385c9e4e3ab30627d6f26d00e2c73eef317493c4ec6d468726cf8"
 dependencies = [
 "cfg-if",
 "libc",
- "redox_syscall 0.5.2",
+ "redox_syscall 0.5.3",
 "smallvec",
 "windows-targets 0.52.6",
 ]
@@ -527,36 +508,6 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"

-[[package]]
-name = "predicates"
-version = "3.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68b87bfd4605926cdfefc1c3b5f8fe560e3feca9d5552cf68c466d3d8236c7e8"
-dependencies = [
- "anstyle",
- "difflib",
- "float-cmp",
- "normalize-line-endings",
- "predicates-core",
- "regex",
-]
-
-[[package]]
-name = "predicates-core"
-version = "1.0.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b794032607612e7abeb4db69adb4e33590fa6cf1149e95fd7cb00e634b92f174"
-
-[[package]]
-name = "predicates-tree"
-version = "1.0.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "368ba315fb8c5052ab692e68a0eefec6ec57b23a36959c14496f0b0df2c0cecf"
-dependencies = [
- "predicates-core",
- "termtree",
-]
-
 [[package]]
 name = "proc-macro2"
 version = "1.0.86"
@@ -577,18 +528,18 @@ dependencies = [

 [[package]]
 name = "ratatui"
-version = "0.27.0"
+version = "0.28.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d16546c5b5962abf8ce6e2881e722b4e0ae3b6f1a08a26ae3573c55853ca68d3"
+checksum = "5ba6a365afbe5615999275bea2446b970b10a41102500e27ce7678d50d978303"
 dependencies = [
 "bitflags 2.6.0",
 "cassowary",
 "compact_str",
 "crossterm",
+ "instability",
 "itertools",
 "lru",
 "paste",
- "stability",
 "strum",
 "strum_macros",
 "unicode-segmentation",
@@ -607,64 +558,46 @@ dependencies = [

 [[package]]
 name = "redox_syscall"
-version = "0.5.2"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c82cf8cff14456045f55ec4241383baeff27af886adb72ffb2162f99911de0fd"
+checksum = "2a908a6e00f1fdd0dfd9c0eb08ce85126f6d8bbda50017e74bc4a4b7d4a926a4"
 dependencies = [
 "bitflags 2.6.0",
 ]

 [[package]]
-name = "regex"
-version = "1.10.5"
+name = "rustix"
+version = "0.38.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b91213439dad192326a0d7c6ee3955910425f441d7038e0d6933b0aec5c4517f"
+checksum = "70dc5ec042f7a43c4a73241207cecc9873a06d45debb38b329f8541d85c2730f"
 dependencies = [
- "aho-corasick",
- "memchr",
- "regex-automata",
- "regex-syntax",
+ "bitflags 2.6.0",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys 0.52.0",
 ]

-[[package]]
-name = "regex-automata"
-version = "0.4.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38caf58cc5ef2fed281f89292ef23f6365465ed9a41b7a7754eb4e26496c92df"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-syntax"
-version = "0.8.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a66a03ae7c801facd77a29370b4faec201768915ac14a721ba36f20bc9c209b"
-
 [[package]]
 name = "rustlings"
-version = "6.1.0"
+version = "6.2.0"
 dependencies = [
+ "ahash",
 "anyhow",
- "assert_cmd",
 "clap",
- "crossterm",
- "hashbrown",
 "notify-debouncer-mini",
 "os_pipe",
- "predicates",
 "ratatui",
 "rustlings-macros",
 "serde",
 "serde_json",
+ "tempfile",
 "toml_edit",
 ]

 [[package]]
 name = "rustlings-macros"
-version = "6.1.0"
+version = "6.2.0"
 dependencies = [
 "quote",
 "serde",
@@ -700,18 +633,18 @@ checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"

 [[package]]
 name = "serde"
-version = "1.0.204"
+version = "1.0.205"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bc76f558e0cbb2a839d37354c575f1dc3fdc6546b5be373ba43d95f231bf7c12"
+checksum = "e33aedb1a7135da52b7c21791455563facbbcc43d0f0f66165b42c21b3dfb150"
 dependencies = [
 "serde_derive",
 ]

 [[package]]
 name = "serde_derive"
-version = "1.0.204"
+version = "1.0.205"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0cd7e117be63d3c3678776753929474f3b04a43a080c744d6b0ae2a8c28e222"
+checksum = "692d6f5ac90220161d6774db30c662202721e64aed9058d2c394f451261420c1"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -720,20 +653,21 @@ dependencies = [

 [[package]]
 name = "serde_json"
-version = "1.0.120"
+version = "1.0.122"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e0d21c9a8cae1235ad58a00c11cb40d4b1e5c784f1ef2c537876ed6ffd8b7c5"
+checksum = "784b6203951c57ff748476b126ccb5e8e2959a5c19e5c617ab1956be3dbc68da"
 dependencies = [
 "itoa",
+ "memchr",
 "ryu",
 "serde",
 ]

 [[package]]
 name = "serde_spanned"
-version = "0.6.6"
+version = "0.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79e674e01f999af37c49f70a6ede167a8a60b2503e56c5599532a65baa5969a0"
+checksum = "eb5b1b31579f3811bf615c144393417496f152e12ac8b7663bf664f4a815306d"
 dependencies = [
 "serde",
 ]
@@ -750,12 +684,12 @@ dependencies = [

 [[package]]
 name = "signal-hook-mio"
-version = "0.2.3"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29ad2e15f37ec9a6cc544097b78a1ec90001e9f71b81338ca39f430adaca99af"
+checksum = "34db1a06d485c9142248b7a054f034b349b212551f3dfd19c94d45a754a217cd"
 dependencies = [
 "libc",
- "mio",
+ "mio 1.0.1",
 "signal-hook",
 ]

@@ -774,16 +708,6 @@ version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"

-[[package]]
-name = "stability"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d904e7009df136af5297832a3ace3370cd14ff1546a232f4f185036c2736fcac"
-dependencies = [
- "quote",
- "syn",
-]
-
 [[package]]
 name = "static_assertions"
 version = "1.1.0"
@@ -820,9 +744,9 @@ dependencies = [

 [[package]]
 name = "syn"
-version = "2.0.70"
+version = "2.0.72"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f0209b68b3613b093e0ec905354eccaedcfe83b8cb37cbdeae64026c3064c16"
+checksum = "dc4b9b9bf2add8093d3f2c0204471e951b2285580335de42f9d2534f3ae7a8af"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -830,25 +754,32 @@ dependencies = [
 ]

 [[package]]
-name = "termtree"
-version = "0.4.1"
+name = "tempfile"
+version = "3.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3369f5ac52d5eb6ab48c6b4ffdc8efbcad6b89c765749064ba298f2c68a16a76"
+checksum = "04cbcdd0c794ebb0d4cf35e88edd2f7d2c4c3e9a5a6dab322839b321c6a87a64"
+dependencies = [
+ "cfg-if",
+ "fastrand",
+ "once_cell",
+ "rustix",
+ "windows-sys 0.59.0",
+]

 [[package]]
 name = "toml_datetime"
-version = "0.6.6"
+version = "0.6.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4badfd56924ae69bcc9039335b2e017639ce3f9b001c393c1b2d1ef846ce2cbf"
+checksum = "0dd7358ecb8fc2f8d014bf86f6f638ce72ba252a2c3a2572f2a795f1d23efb41"
 dependencies = [
 "serde",
 ]

 [[package]]
 name = "toml_edit"
-version = "0.22.15"
+version = "0.22.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d59a3a72298453f564e2b111fa896f8d07fabb36f51f06d7e875fc5e0b5a3ef1"
+checksum = "583c44c02ad26b0c3f3066fe629275e50627026c51ac2e595cca4c230ce1ce1d"
 dependencies = [
 "indexmap",
 "serde",
@@ -894,18 +825,9 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"

 [[package]]
 name = "version_check"
-version = "0.9.4"
+version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
-
-[[package]]
-name = "wait-timeout"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f200f5b12eb75f8c1ed65abd4b2db8a6e1b138a20de009dacee265a2498f3f6"
-dependencies = [
- "libc",
-]
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"

 [[package]]
 name = "walkdir"
@@ -941,11 +863,11 @@ checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"

 [[package]]
 name = "winapi-util"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d4cc384e1e73b93bafa6fb4f1df8c41695c8a91cf9c4c64358067d15a7b6c6b"
+checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -972,6 +894,15 @@ dependencies = [
 "windows-targets 0.52.6",
 ]

+[[package]]
+name = "windows-sys"
+version = "0.59.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets 0.52.6",
+]
+
 [[package]]
 name = "windows-targets"
 version = "0.48.5"
@@ -1095,9 +1026,9 @@ checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"

 [[package]]
 name = "winnow"
-version = "0.6.13"
+version = "0.6.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59b5e5f6c299a3c7890b876a2a587f3115162487e704907d9b6cd29473052ba1"
+checksum = "68a9bda4691f099d435ad181000724da8e5899daa10713c2d432552b9ccd3a6f"
 dependencies = [
 "memchr",
 ]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,27 +1,26 @@
 [workspace]
 resolver = "2"
 exclude = [
-  "tests/fixture/failure",
-  "tests/fixture/state",
-  "tests/fixture/success",
+  "tests/test_exercises",
  "dev",
 ]

 [workspace.package]
-version = "6.1.0"
+version = "6.2.0"
 authors = [
-  "Liv <mokou@fastmail.com>",
-  "Mo Bitar <mo8it@proton.me>",
+  "Mo Bitar <mo8it@proton.me>", # https://github.com/mo8it
+  "Liv <mokou@fastmail.com>", # https://github.com/shadows-withal
  # Alumni
-  "Carol (Nichols || Goulding) <carol.nichols@gmail.com>",
+  "Carol (Nichols || Goulding) <carol.nichols@gmail.com>", # https://github.com/carols10cents
 ]
 repository = "https://github.com/rust-lang/rustlings"
 license = "MIT"
-edition = "2021"
+edition = "2021" # On Update: Update the edition of the `rustfmt` command that checks the solutions.
+rust-version = "1.80"

 [workspace.dependencies]
-serde = { version = "1.0.204", features = ["derive"] }
-toml_edit = { version = "0.22.15", default-features = false, features = ["parse", "serde"] }
+serde = { version = "1.0.205", features = ["derive"] }
+toml_edit = { version = "0.22.20", default-features = false, features = ["parse", "serde"] }

 [package]
 name = "rustlings"
@@ -31,6 +30,7 @@ authors.workspace = true
 repository.workspace = true
 license.workspace = true
 edition.workspace = true
+rust-version.workspace = true
 keywords = [
  "exercise",
  "learning",
@@ -46,21 +46,19 @@ include = [
 ]

 [dependencies]
+ahash = { version = "0.8.11", default-features = false }
 anyhow = "1.0.86"
-clap = { version = "4.5.9", features = ["derive"] }
-crossterm = "0.27.0"
-hashbrown = "0.14.5"
+clap = { version = "4.5.14", features = ["derive"] }
 notify-debouncer-mini = { version = "0.4.1", default-features = false }
-os_pipe = "1.2.0"
-ratatui = { version = "0.27.0", default-features = false, features = ["crossterm"] }
-rustlings-macros = { path = "rustlings-macros", version = "=6.1.0" }
-serde_json = "1.0.120"
+os_pipe = "1.2.1"
+ratatui = { version = "0.28.0", default-features = false, features = ["crossterm"] }
+rustlings-macros = { path = "rustlings-macros", version = "=6.2.0" }
+serde_json = "1.0.122"
 serde.workspace = true
 toml_edit.workspace = true

 [dev-dependencies]
-assert_cmd = "2.0.14"
-predicates = "3.1.0"
+tempfile = "3.12.0"

 [profile.release]
 panic = "abort"
@@ -70,3 +68,7 @@ panic = "abort"

 [package.metadata.release]
 pre-release-hook = ["./release-hook.sh"]
+
+# TODO: Remove after the following fix is released: https://github.com/rust-lang/rust-clippy/pull/13102
+[lints.clippy]
+needless_option_as_deref = "allow"
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ It contains code examples and exercises similar to Rustlings, but online.

 ### Installing Rust

-Before installing Rustlings, you need to have _Rust installed_.
+Before installing Rustlings, you need to have the **latest version of Rust** installed.
 Visit [www.rust-lang.org/tools/install](https://www.rust-lang.org/tools/install) for further instructions on installing Rust.
 This will also install _Cargo_, Rust's package/project manager.

@@ -53,6 +53,21 @@ After installing Rustlings, run the following command to initialize the `rustlin
 rustlings init
 ```

+<details>
+<summary><strong>If the command <code>rustlings</code> can't be found…</strong> (<em>click to expand</em>)</summary>
+
+You are probably using Linux and installed Rust using your package manager.
+
+Cargo installs binaries to the directory `~/.cargo/bin`.
+Sadly, package managers often don't add `~/.cargo/bin` to your `PATH` environment variable.
+
+The solution is to …
+
+- either add `~/.cargo/bin` manually to `PATH`
+- or to uninstall Rust from the package manager and install it using the official way with `rustup`: https://www.rust-lang.org/tools/install
+
+</details>
+
 Now, go into the newly initialized directory and launch Rustlings for further instructions on getting started with the exercises:

 ```bash
@@ -73,8 +88,6 @@ While working with Rustlings, please use a modern terminal for the best user exp
 The default terminal on Linux and Mac should be sufficient.
 On Windows, we recommend the [Windows Terminal](https://aka.ms/terminal).

-If you use VS Code, the builtin terminal should also be fine.
-
 ## Doing exercises

 The exercises are sorted by topic and can be found in the subdirectory `exercises/<topic>`.
--- a/dev/Cargo.toml
+++ b/dev/Cargo.toml
@@ -195,3 +195,9 @@ name = "exercises"
 edition = "2021"
 # Don't publish the exercises on crates.io!
 publish = false
+
+[profile.release]
+panic = "abort"
+
+[profile.dev]
+panic = "abort"
--- a/exercises/11_hashmaps/hashmaps2.rs
+++ b/exercises/11_hashmaps/hashmaps2.rs
@@ -6,7 +6,7 @@
 // must add fruit to the basket so that there is at least one of each kind and
 // more than 11 in total - we have a lot of mouths to feed. You are not allowed
 // to insert any more of the fruits that are already in the basket (Apple,
-// Mango, and Lyche).
+// Mango, and Lychee).

 use std::collections::HashMap;

--- a/exercises/11_hashmaps/hashmaps3.rs
+++ b/exercises/11_hashmaps/hashmaps3.rs
@@ -10,12 +10,12 @@ use std::collections::HashMap;

 // A structure to store the goal details of a team.
 #[derive(Default)]
-struct Team {
+struct TeamScores {
    goals_scored: u8,
    goals_conceded: u8,
 }

-fn build_scores_table(results: &str) -> HashMap<&str, Team> {
+fn build_scores_table(results: &str) -> HashMap<&str, TeamScores> {
    // The name of the team is the key and its associated struct is the value.
    let mut scores = HashMap::new();

--- a/exercises/13_error_handling/errors6.rs
+++ b/exercises/13_error_handling/errors6.rs
@@ -25,7 +25,7 @@ impl ParsePosNonzeroError {
    }

    // TODO: Add another error conversion function here.
-    // fn from_parseint(???) -> Self { ??? }
+    // fn from_parse_int(???) -> Self { ??? }
 }

 #[derive(PartialEq, Debug)]
--- a/exercises/17_tests/tests3.rs
+++ b/exercises/17_tests/tests3.rs
@@ -9,7 +9,7 @@ impl Rectangle {
        if width <= 0 || height <= 0 {
            // Returning a `Result` would be better here. But we want to learn
            // how to test functions that can panic.
-            panic!("Rectangle width and height can't be negative");
+            panic!("Rectangle width and height must be positive");
        }

        Rectangle { width, height }
--- a/exercises/quizzes/quiz2.rs
+++ b/exercises/quizzes/quiz2.rs
@@ -26,7 +26,7 @@ enum Command {
 mod my_module {
    use super::Command;

-    // TODO: Complete the function.
+    // TODO: Complete the function as described above.
    // pub fn transformer(input: ???) -> ??? { ??? }
 }

--- a/release-hook.sh
+++ b/release-hook.sh
@@ -3,7 +3,11 @@
 # Error out if any command fails
 set -e

-cargo run -- dev check
 typos
-cargo outdated -w --exit-code 1
+cargo upgrades
+
+# Similar to CI
+cargo clippy -- --deny warnings
+cargo fmt --all --check
 cargo test --workspace --all-targets
+cargo run -- dev check --require-solutions
--- a/rustlings-macros/Cargo.toml
+++ b/rustlings-macros/Cargo.toml
@@ -6,6 +6,7 @@ authors.workspace = true
 repository.workspace = true
 license.workspace = true
 edition.workspace = true
+rust-version.workspace = true
 include = [
  "/src/",
  "/info.toml",
--- a/rustlings-macros/info.toml
+++ b/rustlings-macros/info.toml
@@ -498,7 +498,10 @@ some of them:
 https://doc.rust-lang.org/std/string/struct.String.html#method.trim

 For the `compose_me` method: You can either use the `format!` macro, or convert
-the string slice into an owned string, which you can then freely extend."""
+the string slice into an owned string, which you can then freely extend.
+
+For the `replace_me` method, you can check out the `replace` method:
+https://doc.rust-lang.org/std/string/struct.String.html#method.replace"""

 [[exercises]]
 name = "strings4"
@@ -568,7 +571,7 @@ name = "hashmaps3"
 dir = "11_hashmaps"
 hint = """
 Hint 1: Use the `entry()` and `or_insert()` (or `or_insert_with()`) methods of
-        `HashMap` to insert the default value of `Team` if a team doesn't
+        `HashMap` to insert the default value of `TeamScores` if a team doesn't
        exist in the table yet.

 Learn more in The Book:
--- a/solutions/11_hashmaps/hashmaps2.rs
+++ b/solutions/11_hashmaps/hashmaps2.rs
@@ -5,7 +5,8 @@
 // Apple (4), Mango (2) and Lychee (5) are already in the basket hash map. You
 // must add fruit to the basket so that there is at least one of each kind and
 // more than 11 in total - we have a lot of mouths to feed. You are not allowed
-// to insert any more of these fruits!
+// to insert any more of the fruits that are already in the basket (Apple,
+// Mango, and Lychee).

 use std::collections::HashMap;

--- a/solutions/11_hashmaps/hashmaps3.rs
+++ b/solutions/11_hashmaps/hashmaps3.rs
@@ -10,12 +10,12 @@ use std::collections::HashMap;

 // A structure to store the goal details of a team.
 #[derive(Default)]
-struct Team {
+struct TeamScores {
    goals_scored: u8,
    goals_conceded: u8,
 }

-fn build_scores_table(results: &str) -> HashMap<&str, Team> {
+fn build_scores_table(results: &str) -> HashMap<&str, TeamScores> {
    // The name of the team is the key and its associated struct is the value.
    let mut scores = HashMap::new();

@@ -28,13 +28,17 @@ fn build_scores_table(results: &str) -> HashMap<&str, Team> {
        let team_2_score: u8 = split_iterator.next().unwrap().parse().unwrap();

        // Insert the default with zeros if a team doesn't exist yet.
-        let team_1 = scores.entry(team_1_name).or_insert_with(Team::default);
+        let team_1 = scores
+            .entry(team_1_name)
+            .or_insert_with(TeamScores::default);
        // Update the values.
        team_1.goals_scored += team_1_score;
        team_1.goals_conceded += team_2_score;

        // Similarely for the second team.
-        let team_2 = scores.entry(team_2_name).or_insert_with(Team::default);
+        let team_2 = scores
+            .entry(team_2_name)
+            .or_insert_with(TeamScores::default);
        team_2.goals_scored += team_2_score;
        team_2.goals_conceded += team_1_score;
    }
--- a/solutions/13_error_handling/errors6.rs
+++ b/solutions/13_error_handling/errors6.rs
@@ -24,7 +24,7 @@ impl ParsePosNonzeroError {
        Self::Creation(err)
    }

-    fn from_parseint(err: ParseIntError) -> Self {
+    fn from_parse_int(err: ParseIntError) -> Self {
        Self::ParseInt(err)
    }
 }
@@ -44,7 +44,7 @@ impl PositiveNonzeroInteger {
    fn parse(s: &str) -> Result<Self, ParsePosNonzeroError> {
        // Return an appropriate error instead of panicking when `parse()`
        // returns an error.
-        let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parseint)?;
+        let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parse_int)?;
        //                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        Self::new(x).map_err(ParsePosNonzeroError::from_creation)
    }
--- a/solutions/17_tests/tests3.rs
+++ b/solutions/17_tests/tests3.rs
@@ -9,7 +9,7 @@ impl Rectangle {
        if width <= 0 || height <= 0 {
            // Returning a `Result` would be better here. But we want to learn
            // how to test functions that can panic.
-            panic!("Rectangle width and height can't be negative");
+            panic!("Rectangle width and height must be positive");
        }

        Rectangle { width, height }
--- a/solutions/README.md
+++ b/solutions/README.md
@@ -0,0 +1,6 @@
+# Official Rustlings solutions
+
+Before you finish an exercise, its solution file will only contain an empty `main` function.
+The content of this file will be automatically replaced by the actual solution once you finish the exercise.
+
+Note that these solution are often only _one possibility_ to solve an exercise.
--- a/src/app_state.rs
+++ b/src/app_state.rs
@@ -1,19 +1,19 @@
-use anyhow::{bail, Context, Result};
-use crossterm::style::Stylize;
-use serde::Deserialize;
+use anyhow::{bail, Context, Error, Result};
 use std::{
    fs::{self, File},
    io::{Read, StdoutLock, Write},
-    path::{Path, PathBuf},
+    path::Path,
    process::{Command, Stdio},
+    thread,
 };

 use crate::{
    clear_terminal,
+    cmd::CmdRunner,
+    collections::hash_set_with_capacity,
    embedded::EMBEDDED_FILES,
-    exercise::{Exercise, RunnableExercise, OUTPUT_CAPACITY},
+    exercise::{Exercise, RunnableExercise},
    info_file::ExerciseInfo,
-    DEBUG_PROFILE,
 };

 const STATE_FILE_NAME: &str = ".rustlings-state.txt";
@@ -34,31 +34,6 @@ pub enum StateFileStatus {
    NotRead,
 }

-// Parses parts of the output of `cargo metadata`.
-#[derive(Deserialize)]
-struct CargoMetadata {
-    target_directory: PathBuf,
-}
-
-pub fn parse_target_dir() -> Result<PathBuf> {
-    // Get the target directory from Cargo.
-    let metadata_output = Command::new("cargo")
-        .arg("metadata")
-        .arg("-q")
-        .arg("--format-version")
-        .arg("1")
-        .arg("--no-deps")
-        .stdin(Stdio::null())
-        .stderr(Stdio::inherit())
-        .output()
-        .context(CARGO_METADATA_ERR)?
-        .stdout;
-
-    serde_json::de::from_slice::<CargoMetadata>(&metadata_output)
-        .context("Failed to read the field `target_directory` from the `cargo metadata` output")
-        .map(|metadata| metadata.target_directory)
-}
-
 pub struct AppState {
    current_exercise_ind: usize,
    exercises: Vec<Exercise>,
@@ -68,8 +43,7 @@ pub struct AppState {
    // Preallocated buffer for reading and writing the state file.
    file_buf: Vec<u8>,
    official_exercises: bool,
-    // Cargo's target directory.
-    target_dir: PathBuf,
+    cmd_runner: CmdRunner,
 }

 impl AppState {
@@ -96,7 +70,7 @@ impl AppState {
            return StateFileStatus::NotRead;
        }

-        let mut done_exercises = hashbrown::HashSet::with_capacity(self.exercises.len());
+        let mut done_exercises = hash_set_with_capacity(self.exercises.len());

        for done_exerise_name in lines {
            if done_exerise_name.is_empty() {
@@ -123,7 +97,7 @@ impl AppState {
        exercise_infos: Vec<ExerciseInfo>,
        final_message: String,
    ) -> Result<(Self, StateFileStatus)> {
-        let target_dir = parse_target_dir()?;
+        let cmd_runner = CmdRunner::build()?;

        let exercises = exercise_infos
            .into_iter()
@@ -134,8 +108,7 @@ impl AppState {
                let path = exercise_info.path().leak();
                let name = exercise_info.name.leak();
                let dir = exercise_info.dir.map(|dir| &*dir.leak());
-
-                let hint = exercise_info.hint.trim().to_owned();
+                let hint = exercise_info.hint.leak().trim_ascii();

                Exercise {
                    dir,
@@ -157,7 +130,7 @@ impl AppState {
            final_message,
            file_buf: Vec::with_capacity(2048),
            official_exercises: !Path::new("info.toml").exists(),
-            target_dir,
+            cmd_runner,
        };

        let state_file_status = slf.update_from_file();
@@ -186,8 +159,8 @@ impl AppState {
    }

    #[inline]
-    pub fn target_dir(&self) -> &Path {
-        &self.target_dir
+    pub fn cmd_runner(&self) -> &CmdRunner {
+        &self.cmd_runner
    }

    // Write the state file.
@@ -336,7 +309,7 @@ impl AppState {
    /// Official exercises: Dump the solution file form the binary and return its path.
    /// Third-party exercises: Check if a solution file exists and return its path in that case.
    pub fn current_solution_path(&self) -> Result<Option<String>> {
-        if DEBUG_PROFILE {
+        if cfg!(debug_assertions) {
            return Ok(None);
        }

@@ -373,34 +346,49 @@ impl AppState {

        if let Some(ind) = self.next_pending_exercise_ind() {
            self.set_current_exercise_ind(ind)?;
-
            return Ok(ExercisesProgress::NewPending);
        }

        writer.write_all(RERUNNING_ALL_EXERCISES_MSG)?;

-        let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
-        for (exercise_ind, exercise) in self.exercises().iter().enumerate() {
-            write!(writer, "Running {exercise} ... ")?;
-            writer.flush()?;
+        let n_exercises = self.exercises.len();

-            let success = exercise.run_exercise(&mut output, &self.target_dir)?;
-            if !success {
-                writeln!(writer, "{}\n", "FAILED".red())?;
+        let pending_exercise_ind = thread::scope(|s| {
+            let handles = self
+                .exercises
+                .iter_mut()
+                .map(|exercise| {
+                    s.spawn(|| {
+                        let success = exercise.run_exercise(None, &self.cmd_runner)?;
+                        exercise.done = success;
+                        Ok::<_, Error>(success)
+                    })
+                })
+                .collect::<Vec<_>>();

-                self.current_exercise_ind = exercise_ind;
+            for (exercise_ind, handle) in handles.into_iter().enumerate() {
+                write!(writer, "\rProgress: {exercise_ind}/{n_exercises}")?;
+                writer.flush()?;

-                // No check if the exercise is done before setting it to pending
-                // because no pending exercise was found.
-                self.exercises[exercise_ind].done = false;
-                self.n_done -= 1;
-
-                self.write()?;
-
-                return Ok(ExercisesProgress::NewPending);
+                let success = handle.join().unwrap()?;
+                if !success {
+                    writer.write_all(b"\n\n")?;
+                    return Ok(Some(exercise_ind));
+                }
            }

-            writeln!(writer, "{}", "ok".green())?;
+            Ok::<_, Error>(None)
+        })?;
+
+        if let Some(pending_exercise_ind) = pending_exercise_ind {
+            self.current_exercise_ind = pending_exercise_ind;
+            self.n_done = self
+                .exercises
+                .iter()
+                .filter(|exercise| exercise.done)
+                .count() as u16;
+            self.write()?;
+            return Ok(ExercisesProgress::NewPending);
        }

        // Write that the last exercise is done.
@@ -409,7 +397,7 @@ impl AppState {
        clear_terminal(writer)?;
        writer.write_all(FENISH_LINE.as_bytes())?;

-        let final_message = self.final_message.trim();
+        let final_message = self.final_message.trim_ascii();
        if !final_message.is_empty() {
            writer.write_all(final_message.as_bytes())?;
            writer.write_all(b"\n")?;
@@ -419,14 +407,9 @@ impl AppState {
    }
 }

-const CARGO_METADATA_ERR: &str = "Failed to run the command `cargo metadata …`
-Did you already install Rust?
-Try running `cargo --version` to diagnose the problem.";
-
 const RERUNNING_ALL_EXERCISES_MSG: &[u8] = b"
 All exercises seem to be done.
 Recompiling and running all exercises to make sure that all of them are actually done.
-
 ";

 const FENISH_LINE: &str = "+----------------------------------------------------+
@@ -462,7 +445,7 @@ mod tests {
            path: "exercises/0.rs",
            test: false,
            strict_clippy: false,
-            hint: String::new(),
+            hint: "",
            done: false,
        }
    }
@@ -476,7 +459,7 @@ mod tests {
            final_message: String::new(),
            file_buf: Vec::new(),
            official_exercises: true,
-            target_dir: PathBuf::new(),
+            cmd_runner: CmdRunner::build().unwrap(),
        };

        let mut assert = |done: [bool; 3], expected: [Option<usize>; 3]| {
--- a/src/cmd.rs
+++ b/src/cmd.rs
@@ -1,30 +1,44 @@
-use anyhow::{Context, Result};
-use std::{io::Read, path::Path, process::Command};
+use anyhow::{bail, Context, Result};
+use serde::Deserialize;
+use std::{
+    io::Read,
+    path::PathBuf,
+    process::{Command, Stdio},
+};

 /// Run a command with a description for a possible error and append the merged stdout and stderr.
 /// The boolean in the returned `Result` is true if the command's exit status is success.
-pub fn run_cmd(mut cmd: Command, description: &str, output: &mut Vec<u8>) -> Result<bool> {
-    let (mut reader, writer) = os_pipe::pipe()
-        .with_context(|| format!("Failed to create a pipe to run the command `{description}``"))?;
+fn run_cmd(mut cmd: Command, description: &str, output: Option<&mut Vec<u8>>) -> Result<bool> {
+    let spawn = |mut cmd: Command| {
+        // NOTE: The closure drops `cmd` which prevents a pipe deadlock.
+        cmd.stdin(Stdio::null())
+            .spawn()
+            .with_context(|| format!("Failed to run the command `{description}`"))
+    };

-    let writer_clone = writer.try_clone().with_context(|| {
-        format!("Failed to clone the pipe writer for the command `{description}`")
-    })?;
+    let mut handle = if let Some(output) = output {
+        let (mut reader, writer) = os_pipe::pipe().with_context(|| {
+            format!("Failed to create a pipe to run the command `{description}``")
+        })?;

-    let mut handle = cmd
-        .stdout(writer_clone)
-        .stderr(writer)
-        .spawn()
-        .with_context(|| format!("Failed to run the command `{description}`"))?;
+        let writer_clone = writer.try_clone().with_context(|| {
+            format!("Failed to clone the pipe writer for the command `{description}`")
+        })?;

-    // Prevent pipe deadlock.
-    drop(cmd);
+        cmd.stdout(writer_clone).stderr(writer);
+        let handle = spawn(cmd)?;

-    reader
-        .read_to_end(output)
-        .with_context(|| format!("Failed to read the output of the command `{description}`"))?;
+        reader
+            .read_to_end(output)
+            .with_context(|| format!("Failed to read the output of the command `{description}`"))?;

-    output.push(b'\n');
+        output.push(b'\n');
+
+        handle
+    } else {
+        cmd.stdout(Stdio::null()).stderr(Stdio::null());
+        spawn(cmd)?
+    };

    handle
        .wait()
@@ -32,50 +46,104 @@ pub fn run_cmd(mut cmd: Command, description: &str, output: &mut Vec<u8>) -> Res
        .map(|status| status.success())
 }

-pub struct CargoCmd<'a> {
-    pub subcommand: &'a str,
-    pub args: &'a [&'a str],
-    pub bin_name: &'a str,
-    pub description: &'a str,
-    /// RUSTFLAGS="-A warnings"
-    pub hide_warnings: bool,
-    /// Added as `--target-dir` if `Self::dev` is true.
-    pub target_dir: &'a Path,
-    /// The output buffer to append the merged stdout and stderr.
-    pub output: &'a mut Vec<u8>,
-    /// true while developing Rustlings.
-    pub dev: bool,
+// Parses parts of the output of `cargo metadata`.
+#[derive(Deserialize)]
+struct CargoMetadata {
+    target_directory: PathBuf,
 }

-impl<'a> CargoCmd<'a> {
-    /// Run `cargo SUBCOMMAND --bin EXERCISE_NAME … ARGS`.
-    pub fn run(&mut self) -> Result<bool> {
+pub struct CmdRunner {
+    target_dir: PathBuf,
+}
+
+impl CmdRunner {
+    pub fn build() -> Result<Self> {
+        // Get the target directory from Cargo.
+        let metadata_output = Command::new("cargo")
+            .arg("metadata")
+            .arg("-q")
+            .arg("--format-version")
+            .arg("1")
+            .arg("--no-deps")
+            .stdin(Stdio::null())
+            .stderr(Stdio::inherit())
+            .output()
+            .context(CARGO_METADATA_ERR)?;
+
+        if !metadata_output.status.success() {
+            bail!("The command `cargo metadata …` failed. Are you in the `rustlings/` directory?");
+        }
+
+        let target_dir = serde_json::de::from_slice::<CargoMetadata>(&metadata_output.stdout)
+            .context(
+                "Failed to read the field `target_directory` from the output of the command `cargo metadata …`",
+            )?.target_directory;
+
+        Ok(Self { target_dir })
+    }
+
+    pub fn cargo<'out>(
+        &self,
+        subcommand: &str,
+        bin_name: &str,
+        output: Option<&'out mut Vec<u8>>,
+    ) -> CargoSubcommand<'out> {
        let mut cmd = Command::new("cargo");
-        cmd.arg(self.subcommand);
+        cmd.arg(subcommand).arg("-q").arg("--bin").arg(bin_name);

        // A hack to make `cargo run` work when developing Rustlings.
-        if self.dev {
-            cmd.arg("--manifest-path")
-                .arg("dev/Cargo.toml")
-                .arg("--target-dir")
-                .arg(self.target_dir);
+        #[cfg(debug_assertions)]
+        cmd.arg("--manifest-path")
+            .arg("dev/Cargo.toml")
+            .arg("--target-dir")
+            .arg(&self.target_dir);
+
+        if output.is_some() {
+            cmd.arg("--color").arg("always");
        }

-        cmd.arg("--color")
-            .arg("always")
-            .arg("-q")
-            .arg("--bin")
-            .arg(self.bin_name)
-            .args(self.args);
+        CargoSubcommand { cmd, output }
+    }

-        if self.hide_warnings {
-            cmd.env("RUSTFLAGS", "-A warnings");
-        }
+    /// The boolean in the returned `Result` is true if the command's exit status is success.
+    pub fn run_debug_bin(&self, bin_name: &str, output: Option<&mut Vec<u8>>) -> Result<bool> {
+        // 7 = "/debug/".len()
+        let mut bin_path =
+            PathBuf::with_capacity(self.target_dir.as_os_str().len() + 7 + bin_name.len());
+        bin_path.push(&self.target_dir);
+        bin_path.push("debug");
+        bin_path.push(bin_name);

-        run_cmd(cmd, self.description, self.output)
+        run_cmd(Command::new(&bin_path), &bin_path.to_string_lossy(), output)
    }
 }

+pub struct CargoSubcommand<'out> {
+    cmd: Command,
+    output: Option<&'out mut Vec<u8>>,
+}
+
+impl<'out> CargoSubcommand<'out> {
+    #[inline]
+    pub fn args<'arg, I>(&mut self, args: I) -> &mut Self
+    where
+        I: IntoIterator<Item = &'arg str>,
+    {
+        self.cmd.args(args);
+        self
+    }
+
+    /// The boolean in the returned `Result` is true if the command's exit status is success.
+    #[inline]
+    pub fn run(self, description: &str) -> Result<bool> {
+        run_cmd(self.cmd, description, self.output)
+    }
+}
+
+const CARGO_METADATA_ERR: &str = "Failed to run the command `cargo metadata …`
+Did you already install Rust?
+Try running `cargo --version` to diagnose the problem.";
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -86,7 +154,7 @@ mod tests {
        cmd.arg("Hello");

        let mut output = Vec::with_capacity(8);
-        run_cmd(cmd, "echo …", &mut output).unwrap();
+        run_cmd(cmd, "echo …", Some(&mut output)).unwrap();

        assert_eq!(output, b"Hello\n\n");
    }
--- a/src/collections.rs
+++ b/src/collections.rs
@@ -0,0 +1,10 @@
+use ahash::AHasher;
+use std::hash::BuildHasherDefault;
+
+/// DOS attacks aren't a concern for Rustlings. Therefore, we use `ahash` with fixed seeds.
+pub type HashSet<T> = std::collections::HashSet<T, BuildHasherDefault<AHasher>>;
+
+#[inline]
+pub fn hash_set_with_capacity<T>(capacity: usize) -> HashSet<T> {
+    HashSet::with_capacity_and_hasher(capacity, BuildHasherDefault::<AHasher>::default())
+}
--- a/src/dev.rs
+++ b/src/dev.rs
@@ -2,8 +2,6 @@ use anyhow::{bail, Context, Result};
 use clap::Subcommand;
 use std::path::PathBuf;

-use crate::DEBUG_PROFILE;
-
 mod check;
 mod new;
 mod update;
@@ -32,7 +30,7 @@ impl DevCommands {
    pub fn run(self) -> Result<()> {
        match self {
            Self::New { path, no_git } => {
-                if DEBUG_PROFILE {
+                if cfg!(debug_assertions) {
                    bail!("Disabled in the debug build");
                }

--- a/src/dev/check.rs
+++ b/src/dev/check.rs
@@ -1,22 +1,20 @@
-use anyhow::{anyhow, bail, Context, Result};
+use anyhow::{anyhow, bail, Context, Error, Result};
 use std::{
    cmp::Ordering,
    fs::{self, read_dir, OpenOptions},
    io::{self, Read, Write},
    path::{Path, PathBuf},
-    sync::{
-        atomic::{self, AtomicBool},
-        Mutex,
-    },
+    process::{Command, Stdio},
    thread,
 };

 use crate::{
-    app_state::parse_target_dir,
    cargo_toml::{append_bins, bins_start_end_ind, BINS_BUFFER_CAPACITY},
+    cmd::CmdRunner,
+    collections::{hash_set_with_capacity, HashSet},
    exercise::{RunnableExercise, OUTPUT_CAPACITY},
    info_file::{ExerciseInfo, InfoFile},
-    CURRENT_FORMAT_VERSION, DEBUG_PROFILE,
+    CURRENT_FORMAT_VERSION,
 };

 // Find a char that isn't allowed in the exercise's `name` or `dir`.
@@ -24,33 +22,36 @@ fn forbidden_char(input: &str) -> Option<char> {
    input.chars().find(|c| !c.is_alphanumeric() && *c != '_')
 }

-// Check that the Cargo.toml file is up-to-date.
+// Check that the `Cargo.toml` file is up-to-date.
 fn check_cargo_toml(
    exercise_infos: &[ExerciseInfo],
-    current_cargo_toml: &str,
+    cargo_toml_path: &str,
    exercise_path_prefix: &[u8],
 ) -> Result<()> {
-    let (bins_start_ind, bins_end_ind) = bins_start_end_ind(current_cargo_toml)?;
+    let current_cargo_toml = fs::read_to_string(cargo_toml_path)
+        .with_context(|| format!("Failed to read the file `{cargo_toml_path}`"))?;
+
+    let (bins_start_ind, bins_end_ind) = bins_start_end_ind(&current_cargo_toml)?;

    let old_bins = &current_cargo_toml.as_bytes()[bins_start_ind..bins_end_ind];
    let mut new_bins = Vec::with_capacity(BINS_BUFFER_CAPACITY);
    append_bins(&mut new_bins, exercise_infos, exercise_path_prefix);

    if old_bins != new_bins {
-        if DEBUG_PROFILE {
-            bail!("The file `dev/Cargo.toml` is outdated. Please run `cargo run -- dev update` to update it");
+        if cfg!(debug_assertions) {
+            bail!("The file `dev/Cargo.toml` is outdated. Please run `cargo run -- dev update` to update it. Then run `cargo run -- dev check` again");
        }

-        bail!("The file `Cargo.toml` is outdated. Please run `rustlings dev update` to update it");
+        bail!("The file `Cargo.toml` is outdated. Please run `rustlings dev update` to update it. Then run `rustlings dev check` again");
    }

    Ok(())
 }

 // Check the info of all exercises and return their paths in a set.
-fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<PathBuf>> {
-    let mut names = hashbrown::HashSet::with_capacity(info_file.exercises.len());
-    let mut paths = hashbrown::HashSet::with_capacity(info_file.exercises.len());
+fn check_info_file_exercises(info_file: &InfoFile) -> Result<HashSet<PathBuf>> {
+    let mut names = hash_set_with_capacity(info_file.exercises.len());
+    let mut paths = hash_set_with_capacity(info_file.exercises.len());

    let mut file_buf = String::with_capacity(1 << 14);
    for exercise_info in &info_file.exercises {
@@ -71,7 +72,7 @@ fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<
            }
        }

-        if exercise_info.hint.trim().is_empty() {
+        if exercise_info.hint.trim_ascii().is_empty() {
            bail!("The exercise `{name}` has an empty hint. Please provide a hint or at least tell the user why a hint isn't needed for this exercise");
        }

@@ -111,10 +112,7 @@ fn check_info_file_exercises(info_file: &InfoFile) -> Result<hashbrown::HashSet<
 // Check `dir` for unexpected files.
 // Only Rust files in `allowed_rust_files` and `README.md` files are allowed.
 // Only one level of directory nesting is allowed.
-fn check_unexpected_files(
-    dir: &str,
-    allowed_rust_files: &hashbrown::HashSet<PathBuf>,
-) -> Result<()> {
+fn check_unexpected_files(dir: &str, allowed_rust_files: &HashSet<PathBuf>) -> Result<()> {
    let unexpected_file = |path: &Path| {
        anyhow!("Found the file `{}`. Only `README.md` and Rust files related to an exercise in `info.toml` are allowed in the `{dir}` directory", path.display())
    };
@@ -162,46 +160,45 @@ fn check_unexpected_files(
    Ok(())
 }

-fn check_exercises_unsolved(info_file: &InfoFile, target_dir: &Path) -> Result<()> {
-    let error_occurred = AtomicBool::new(false);
-
+fn check_exercises_unsolved(info_file: &InfoFile, cmd_runner: &CmdRunner) -> Result<()> {
    println!(
        "Running all exercises to check that they aren't already solved. This may take a while…\n",
    );
    thread::scope(|s| {
-        for exercise_info in &info_file.exercises {
-            if exercise_info.skip_check_unsolved {
-                continue;
-            }
-
-            s.spawn(|| {
-                let error = |e| {
-                    let mut stderr = io::stderr().lock();
-                    stderr.write_all(e).unwrap();
-                    stderr.write_all(b"\nProblem with the exercise ").unwrap();
-                    stderr.write_all(exercise_info.name.as_bytes()).unwrap();
-                    stderr.write_all(SEPARATOR).unwrap();
-                    error_occurred.store(true, atomic::Ordering::Relaxed);
-                };
-
-                let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
-                match exercise_info.run_exercise(&mut output, target_dir) {
-                    Ok(true) => error(b"Already solved!"),
-                    Ok(false) => (),
-                    Err(e) => error(e.to_string().as_bytes()),
+        let handles = info_file
+            .exercises
+            .iter()
+            .filter_map(|exercise_info| {
+                if exercise_info.skip_check_unsolved {
+                    return None;
                }
-            });
+
+                Some((
+                    exercise_info.name.as_str(),
+                    s.spawn(|| exercise_info.run_exercise(None, cmd_runner)),
+                ))
+            })
+            .collect::<Vec<_>>();
+
+        for (exercise_name, handle) in handles {
+            let Ok(result) = handle.join() else {
+                bail!("Panic while trying to run the exericse {exercise_name}");
+            };
+
+            match result {
+                Ok(true) => bail!(
+                    "The exercise {exercise_name} is already solved.\n{SKIP_CHECK_UNSOLVED_HINT}",
+                ),
+                Ok(false) => (),
+                Err(e) => return Err(e),
+            }
        }
-    });

-    if error_occurred.load(atomic::Ordering::Relaxed) {
-        bail!(CHECK_EXERCISES_UNSOLVED_ERR);
-    }
-
-    Ok(())
+        Ok(())
+    })
 }

-fn check_exercises(info_file: &InfoFile, target_dir: &Path) -> Result<()> {
+fn check_exercises(info_file: &InfoFile, cmd_runner: &CmdRunner) -> Result<()> {
    match info_file.format_version.cmp(&CURRENT_FORMAT_VERSION) {
        Ordering::Less => bail!("`format_version` < {CURRENT_FORMAT_VERSION} (supported version)\nPlease migrate to the latest format version"),
        Ordering::Greater => bail!("`format_version` > {CURRENT_FORMAT_VERSION} (supported version)\nTry updating the Rustlings program"),
@@ -209,88 +206,123 @@ fn check_exercises(info_file: &InfoFile, target_dir: &Path) -> Result<()> {
    }

    let info_file_paths = check_info_file_exercises(info_file)?;
-    check_unexpected_files("exercises", &info_file_paths)?;
+    let handle = thread::spawn(move || check_unexpected_files("exercises", &info_file_paths));

-    check_exercises_unsolved(info_file, target_dir)
+    check_exercises_unsolved(info_file, cmd_runner)?;
+    handle.join().unwrap()
 }

-fn check_solutions(require_solutions: bool, info_file: &InfoFile, target_dir: &Path) -> Result<()> {
-    let paths = Mutex::new(hashbrown::HashSet::with_capacity(info_file.exercises.len()));
-    let error_occurred = AtomicBool::new(false);
+enum SolutionCheck {
+    Success { sol_path: String },
+    MissingRequired,
+    MissingOptional,
+    RunFailure { output: Vec<u8> },
+    Err(Error),
+}

+fn check_solutions(
+    require_solutions: bool,
+    info_file: &InfoFile,
+    cmd_runner: &CmdRunner,
+) -> Result<()> {
    println!("Running all solutions. This may take a while…\n");
    thread::scope(|s| {
-        for exercise_info in &info_file.exercises {
-            s.spawn(|| {
-                let error = |e| {
-                    let mut stderr = io::stderr().lock();
-                    stderr.write_all(e).unwrap();
-                    stderr
-                        .write_all(b"\nFailed to run the solution of the exercise ")
-                        .unwrap();
-                    stderr.write_all(exercise_info.name.as_bytes()).unwrap();
-                    stderr.write_all(SEPARATOR).unwrap();
-                    error_occurred.store(true, atomic::Ordering::Relaxed);
-                };
+        let handles = info_file
+            .exercises
+            .iter()
+            .map(|exercise_info| {
+                s.spawn(|| {
+                    let sol_path = exercise_info.sol_path();
+                    if !Path::new(&sol_path).exists() {
+                        if require_solutions {
+                            return SolutionCheck::MissingRequired;
+                        }

-                let path = exercise_info.sol_path();
-                if !Path::new(&path).exists() {
-                    if require_solutions {
-                        error(b"Solution missing");
+                        return SolutionCheck::MissingOptional;
                    }

-                    // No solution to check.
-                    return;
-                }
-
-                let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
-                match exercise_info.run_solution(&mut output, target_dir) {
-                    Ok(true) => {
-                        paths.lock().unwrap().insert(PathBuf::from(path));
+                    let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
+                    match exercise_info.run_solution(Some(&mut output), cmd_runner) {
+                        Ok(true) => SolutionCheck::Success { sol_path },
+                        Ok(false) => SolutionCheck::RunFailure { output },
+                        Err(e) => SolutionCheck::Err(e),
                    }
-                    Ok(false) => error(&output),
-                    Err(e) => error(e.to_string().as_bytes()),
+                })
+            })
+            .collect::<Vec<_>>();
+
+        let mut sol_paths = hash_set_with_capacity(info_file.exercises.len());
+        let mut fmt_cmd = Command::new("rustfmt");
+        fmt_cmd
+            .arg("--check")
+            .arg("--edition")
+            .arg("2021")
+            .arg("--color")
+            .arg("always")
+            .stdin(Stdio::null());
+
+        for (exercise_info, handle) in info_file.exercises.iter().zip(handles) {
+            let Ok(check_result) = handle.join() else {
+                bail!(
+                    "Panic while trying to run the solution of the exericse {}",
+                    exercise_info.name,
+                );
+            };
+
+            match check_result {
+                SolutionCheck::Success { sol_path } => {
+                    fmt_cmd.arg(&sol_path);
+                    sol_paths.insert(PathBuf::from(sol_path));
                }
-            });
+                SolutionCheck::MissingRequired => {
+                    bail!(
+                        "The solution of the exercise {} is missing",
+                        exercise_info.name,
+                    );
+                }
+                SolutionCheck::MissingOptional => (),
+                SolutionCheck::RunFailure { output } => {
+                    io::stderr().lock().write_all(&output)?;
+                    bail!(
+                        "Running the solution of the exercise {} failed with the error above",
+                        exercise_info.name,
+                    );
+                }
+                SolutionCheck::Err(e) => return Err(e),
+            }
        }
-    });

-    if error_occurred.load(atomic::Ordering::Relaxed) {
-        bail!("At least one solution failed. See the output above.");
-    }
+        let handle = s.spawn(move || check_unexpected_files("solutions", &sol_paths));

-    check_unexpected_files("solutions", &paths.into_inner().unwrap())?;
+        if !fmt_cmd
+            .status()
+            .context("Failed to run `rustfmt` on all solution files")?
+            .success()
+        {
+            bail!("Some solutions aren't formatted. Run `rustfmt` on them");
+        }

-    Ok(())
+        handle.join().unwrap()
+    })
 }

 pub fn check(require_solutions: bool) -> Result<()> {
    let info_file = InfoFile::parse()?;

-    // A hack to make `cargo run -- dev check` work when developing Rustlings.
-    if DEBUG_PROFILE {
-        check_cargo_toml(
-            &info_file.exercises,
-            include_str!("../../dev-Cargo.toml"),
-            b"../",
-        )?;
+    if cfg!(debug_assertions) {
+        // A hack to make `cargo run -- dev check` work when developing Rustlings.
+        check_cargo_toml(&info_file.exercises, "dev/Cargo.toml", b"../")?;
    } else {
-        let current_cargo_toml =
-            fs::read_to_string("Cargo.toml").context("Failed to read the file `Cargo.toml`")?;
-        check_cargo_toml(&info_file.exercises, &current_cargo_toml, b"")?;
+        check_cargo_toml(&info_file.exercises, "Cargo.toml", b"")?;
    }

-    let target_dir = parse_target_dir()?;
-    check_exercises(&info_file, &target_dir)?;
-    check_solutions(require_solutions, &info_file, &target_dir)?;
+    let cmd_runner = CmdRunner::build()?;
+    check_exercises(&info_file, &cmd_runner)?;
+    check_solutions(require_solutions, &info_file, &cmd_runner)?;

-    println!("\nEverything looks fine!");
+    println!("Everything looks fine!");

    Ok(())
 }

-const SEPARATOR: &[u8] =
-    b"\n========================================================================================\n";
-
-const CHECK_EXERCISES_UNSOLVED_ERR: &str = "At least one exercise is already solved or failed to run. See the output above.
-If this is an intro exercise that is intended to be already solved, add `skip_check_unsolved = true` to the exercise's metadata in the `info.toml` file.";
+const SKIP_CHECK_UNSOLVED_HINT: &str = "If this is an introduction exercise that is intended to be already solved, add `skip_check_unsolved = true` to the exercise's metadata in the `info.toml` file";
--- a/src/dev/new.rs
+++ b/src/dev/new.rs
@@ -76,8 +76,8 @@ pub fn new(path: &Path, no_git: bool) -> Result<()> {

 pub const GITIGNORE: &[u8] = b".rustlings-state.txt
 Cargo.lock
-target
-.vscode
+target/
+.vscode/
 !.vscode/extensions.json
 ";

--- a/src/dev/update.rs
+++ b/src/dev/update.rs
@@ -4,18 +4,19 @@ use std::fs;
 use crate::{
    cargo_toml::updated_cargo_toml,
    info_file::{ExerciseInfo, InfoFile},
-    DEBUG_PROFILE,
 };

 // Update the `Cargo.toml` file.
 fn update_cargo_toml(
    exercise_infos: &[ExerciseInfo],
-    current_cargo_toml: &str,
-    exercise_path_prefix: &[u8],
    cargo_toml_path: &str,
+    exercise_path_prefix: &[u8],
 ) -> Result<()> {
+    let current_cargo_toml = fs::read_to_string(cargo_toml_path)
+        .with_context(|| format!("Failed to read the file `{cargo_toml_path}`"))?;
+
    let updated_cargo_toml =
-        updated_cargo_toml(exercise_infos, current_cargo_toml, exercise_path_prefix)?;
+        updated_cargo_toml(exercise_infos, &current_cargo_toml, exercise_path_prefix)?;

    fs::write(cargo_toml_path, updated_cargo_toml)
        .context("Failed to write the `Cargo.toml` file")?;
@@ -26,21 +27,14 @@ fn update_cargo_toml(
 pub fn update() -> Result<()> {
    let info_file = InfoFile::parse()?;

-    // A hack to make `cargo run -- dev update` work when developing Rustlings.
-    if DEBUG_PROFILE {
-        update_cargo_toml(
-            &info_file.exercises,
-            include_str!("../../dev-Cargo.toml"),
-            b"../",
-            "dev/Cargo.toml",
-        )
-        .context("Failed to update the file `dev/Cargo.toml`")?;
+    if cfg!(debug_assertions) {
+        // A hack to make `cargo run -- dev update` work when developing Rustlings.
+        update_cargo_toml(&info_file.exercises, "dev/Cargo.toml", b"../")
+            .context("Failed to update the file `dev/Cargo.toml`")?;

        println!("Updated `dev/Cargo.toml`");
    } else {
-        let current_cargo_toml =
-            fs::read_to_string("Cargo.toml").context("Failed to read the file `Cargo.toml`")?;
-        update_cargo_toml(&info_file.exercises, &current_cargo_toml, b"", "Cargo.toml")
+        update_cargo_toml(&info_file.exercises, "Cargo.toml", &[])
            .context("Failed to update the file `Cargo.toml`")?;

        println!("Updated `Cargo.toml`");
--- a/src/exercise.rs
+++ b/src/exercise.rs
@@ -1,46 +1,41 @@
 use anyhow::Result;
-use crossterm::style::{style, StyledContent, Stylize};
+use ratatui::crossterm::style::{style, StyledContent, Stylize};
 use std::{
    fmt::{self, Display, Formatter},
    io::Write,
-    path::{Path, PathBuf},
-    process::Command,
 };

-use crate::{
-    cmd::{run_cmd, CargoCmd},
-    in_official_repo,
-    terminal_link::TerminalFileLink,
-    DEBUG_PROFILE,
-};
+use crate::{cmd::CmdRunner, terminal_link::TerminalFileLink};

 /// The initial capacity of the output buffer.
 pub const OUTPUT_CAPACITY: usize = 1 << 14;

 // Run an exercise binary and append its output to the `output` buffer.
 // Compilation must be done before calling this method.
-fn run_bin(bin_name: &str, output: &mut Vec<u8>, target_dir: &Path) -> Result<bool> {
-    writeln!(output, "{}", "Output".underlined())?;
+fn run_bin(
+    bin_name: &str,
+    mut output: Option<&mut Vec<u8>>,
+    cmd_runner: &CmdRunner,
+) -> Result<bool> {
+    if let Some(output) = output.as_deref_mut() {
+        writeln!(output, "{}", "Output".underlined())?;
+    }

-    // 7 = "/debug/".len()
-    let mut bin_path = PathBuf::with_capacity(target_dir.as_os_str().len() + 7 + bin_name.len());
-    bin_path.push(target_dir);
-    bin_path.push("debug");
-    bin_path.push(bin_name);
+    let success = cmd_runner.run_debug_bin(bin_name, output.as_deref_mut())?;

-    let success = run_cmd(Command::new(&bin_path), &bin_path.to_string_lossy(), output)?;
-
-    if !success {
-        // This output is important to show the user that something went wrong.
-        // Otherwise, calling something like `exit(1)` in an exercise without further output
-        // leaves the user confused about why the exercise isn't done yet.
-        writeln!(
-            output,
-            "{}",
-            "The exercise didn't run successfully (nonzero exit code)"
-                .bold()
-                .red(),
-        )?;
+    if let Some(output) = output {
+        if !success {
+            // This output is important to show the user that something went wrong.
+            // Otherwise, calling something like `exit(1)` in an exercise without further output
+            // leaves the user confused about why the exercise isn't done yet.
+            writeln!(
+                output,
+                "{}",
+                "The exercise didn't run successfully (nonzero exit code)"
+                    .bold()
+                    .red(),
+            )?;
+        }
    }

    Ok(success)
@@ -54,7 +49,7 @@ pub struct Exercise {
    pub path: &'static str,
    pub test: bool,
    pub strict_clippy: bool,
-    pub hint: String,
+    pub hint: &'static str,
    pub done: bool,
 }

@@ -77,89 +72,77 @@ pub trait RunnableExercise {

    // Compile, check and run the exercise or its solution (depending on `bin_name´).
    // The output is written to the `output` buffer after clearing it.
-    fn run(&self, bin_name: &str, output: &mut Vec<u8>, target_dir: &Path) -> Result<bool> {
-        output.clear();
-
-        // Developing the official Rustlings.
-        let dev = DEBUG_PROFILE && in_official_repo();
-
-        let build_success = CargoCmd {
-            subcommand: "build",
-            args: &[],
-            bin_name,
-            description: "cargo build …",
-            hide_warnings: false,
-            target_dir,
-            output,
-            dev,
+    fn run(
+        &self,
+        bin_name: &str,
+        mut output: Option<&mut Vec<u8>>,
+        cmd_runner: &CmdRunner,
+    ) -> Result<bool> {
+        if let Some(output) = output.as_deref_mut() {
+            output.clear();
        }
-        .run()?;
+
+        let build_success = cmd_runner
+            .cargo("build", bin_name, output.as_deref_mut())
+            .run("cargo build …")?;
        if !build_success {
            return Ok(false);
        }

-        // Discard the output of `cargo build` because it will be shown again by Clippy.
-        output.clear();
+        // Discard the compiler output because it will be shown again by `cargo test` or Clippy.
+        if let Some(output) = output.as_deref_mut() {
+            output.clear();
+        }
+
+        if self.test() {
+            let output_is_some = output.is_some();
+            let mut test_cmd = cmd_runner.cargo("test", bin_name, output.as_deref_mut());
+            if output_is_some {
+                test_cmd.args(["--", "--color", "always", "--show-output"]);
+            }
+            let test_success = test_cmd.run("cargo test …")?;
+            if !test_success {
+                run_bin(bin_name, output, cmd_runner)?;
+                return Ok(false);
+            }
+
+            // Discard the compiler output because it will be shown again by Clippy.
+            if let Some(output) = output.as_deref_mut() {
+                output.clear();
+            }
+        }
+
+        let mut clippy_cmd = cmd_runner.cargo("clippy", bin_name, output.as_deref_mut());

        // `--profile test` is required to also check code with `[cfg(test)]`.
-        let clippy_args: &[&str] = if self.strict_clippy() {
-            &["--profile", "test", "--", "-D", "warnings"]
+        if self.strict_clippy() {
+            clippy_cmd.args(["--profile", "test", "--", "-D", "warnings"]);
        } else {
-            &["--profile", "test"]
-        };
-        let clippy_success = CargoCmd {
-            subcommand: "clippy",
-            args: clippy_args,
-            bin_name,
-            description: "cargo clippy …",
-            hide_warnings: false,
-            target_dir,
-            output,
-            dev,
-        }
-        .run()?;
-        if !clippy_success {
-            return Ok(false);
+            clippy_cmd.args(["--profile", "test"]);
        }

-        if !self.test() {
-            return run_bin(bin_name, output, target_dir);
-        }
+        let clippy_success = clippy_cmd.run("cargo clippy …")?;
+        let run_success = run_bin(bin_name, output, cmd_runner)?;

-        let test_success = CargoCmd {
-            subcommand: "test",
-            args: &["--", "--color", "always", "--show-output"],
-            bin_name,
-            description: "cargo test …",
-            // Hide warnings because they are shown by Clippy.
-            hide_warnings: true,
-            target_dir,
-            output,
-            dev,
-        }
-        .run()?;
-
-        let run_success = run_bin(bin_name, output, target_dir)?;
-
-        Ok(test_success && run_success)
+        Ok(clippy_success && run_success)
    }

    /// Compile, check and run the exercise.
    /// The output is written to the `output` buffer after clearing it.
    #[inline]
-    fn run_exercise(&self, output: &mut Vec<u8>, target_dir: &Path) -> Result<bool> {
-        self.run(self.name(), output, target_dir)
+    fn run_exercise(&self, output: Option<&mut Vec<u8>>, cmd_runner: &CmdRunner) -> Result<bool> {
+        self.run(self.name(), output, cmd_runner)
    }

    /// Compile, check and run the exercise's solution.
    /// The output is written to the `output` buffer after clearing it.
-    fn run_solution(&self, output: &mut Vec<u8>, target_dir: &Path) -> Result<bool> {
+    fn run_solution(&self, output: Option<&mut Vec<u8>>, cmd_runner: &CmdRunner) -> Result<bool> {
        let name = self.name();
-        let mut bin_name = String::with_capacity(name.len());
+        let mut bin_name = String::with_capacity(name.len() + 4);
        bin_name.push_str(name);
        bin_name.push_str("_sol");

-        self.run(&bin_name, output, target_dir)
+        self.run(&bin_name, output, cmd_runner)
    }
 }

--- a/src/init.rs
+++ b/src/init.rs
@@ -1,32 +1,91 @@
 use anyhow::{bail, Context, Result};
-use crossterm::style::Stylize;
+use ratatui::crossterm::style::Stylize;
+use serde::Deserialize;
 use std::{
    env::set_current_dir,
    fs::{self, create_dir},
-    io::ErrorKind,
-    path::Path,
+    io::{self, Write},
+    path::{Path, PathBuf},
    process::{Command, Stdio},
 };

-use crate::{cargo_toml::updated_cargo_toml, embedded::EMBEDDED_FILES, info_file::InfoFile};
+use crate::{
+    cargo_toml::updated_cargo_toml, embedded::EMBEDDED_FILES, info_file::InfoFile,
+    term::press_enter_prompt,
+};
+
+#[derive(Deserialize)]
+struct CargoLocateProject {
+    root: PathBuf,
+}

 pub fn init() -> Result<()> {
-    // Prevent initialization in a directory that contains the file `Cargo.toml`.
-    // This can mean that Rustlings was already initialized in this directory.
-    // Otherwise, this can cause problems with Cargo workspaces.
-    if Path::new("Cargo.toml").exists() {
-        bail!(CARGO_TOML_EXISTS_ERR);
+    let rustlings_dir = Path::new("rustlings");
+    if rustlings_dir.exists() {
+        bail!(RUSTLINGS_DIR_ALREADY_EXISTS_ERR);
    }

-    let rustlings_path = Path::new("rustlings");
-    if let Err(e) = create_dir(rustlings_path) {
-        if e.kind() == ErrorKind::AlreadyExists {
-            bail!(RUSTLINGS_DIR_ALREADY_EXISTS_ERR);
+    let locate_project_output = Command::new("cargo")
+        .arg("locate-project")
+        .arg("-q")
+        .arg("--workspace")
+        .stdin(Stdio::null())
+        .stderr(Stdio::null())
+        .output()
+        .context(CARGO_LOCATE_PROJECT_ERR)?;
+
+    let mut stdout = io::stdout().lock();
+    let mut init_git = true;
+
+    if locate_project_output.status.success() {
+        if Path::new("exercises").exists() && Path::new("solutions").exists() {
+            bail!(IN_INITIALIZED_DIR_ERR);
        }
-        return Err(e.into());
+
+        let workspace_manifest =
+            serde_json::de::from_slice::<CargoLocateProject>(&locate_project_output.stdout)
+                .context(
+                    "Failed to read the field `root` from the output of `cargo locate-project …`",
+                )?
+                .root;
+
+        let workspace_manifest_content = fs::read_to_string(&workspace_manifest)
+            .with_context(|| format!("Failed to read the file {}", workspace_manifest.display()))?;
+        if !workspace_manifest_content.contains("[workspace]\n")
+            && !workspace_manifest_content.contains("workspace.")
+        {
+            bail!("The current directory is already part of a Cargo project.\nPlease initialize Rustlings in a different directory");
+        }
+
+        stdout.write_all(b"This command will create the directory `rustlings/` as a member of this Cargo workspace.\nPress ENTER to continue ")?;
+        press_enter_prompt(&mut stdout)?;
+
+        // Make sure "rustlings" is added to `workspace.members` by making
+        // Cargo initialize a new project.
+        let status = Command::new("cargo")
+            .arg("new")
+            .arg("-q")
+            .arg("--vcs")
+            .arg("none")
+            .arg("rustlings")
+            .stdin(Stdio::null())
+            .stdout(Stdio::null())
+            .status()?;
+        if !status.success() {
+            bail!("Failed to initialize a new Cargo workspace member.\nPlease initialize Rustlings in a different directory");
+        }
+
+        stdout.write_all(b"The directory `rustlings` has been added to `workspace.members` in the `Cargo.toml` file of this Cargo workspace.\n")?;
+        fs::remove_dir_all("rustlings")
+            .context("Failed to remove the temporary directory `rustlings/`")?;
+        init_git = false;
+    } else {
+        stdout.write_all(b"This command will create the directory `rustlings/` which will contain the exercises.\nPress ENTER to continue ")?;
+        press_enter_prompt(&mut stdout)?;
    }

-    set_current_dir("rustlings")
+    create_dir(rustlings_dir).context("Failed to create the `rustlings/` directory")?;
+    set_current_dir(rustlings_dir)
        .context("Failed to change the current directory to `rustlings/`")?;

    let info_file = InfoFile::parse()?;
@@ -35,6 +94,11 @@ pub fn init() -> Result<()> {
        .context("Failed to initialize the `rustlings/exercises` directory")?;

    create_dir("solutions").context("Failed to create the `solutions/` directory")?;
+    fs::write(
+        "solutions/README.md",
+        include_bytes!("../solutions/README.md"),
+    )
+    .context("Failed to create the file rustlings/solutions/README.md")?;
    for dir in EMBEDDED_FILES.exercise_dirs {
        let mut dir_path = String::with_capacity(10 + dir.name.len());
        dir_path.push_str("solutions/");
@@ -70,41 +134,46 @@ pub fn init() -> Result<()> {
    fs::write(".vscode/extensions.json", VS_CODE_EXTENSIONS_JSON)
        .context("Failed to create the file `rustlings/.vscode/extensions.json`")?;

-    // Ignore any Git error because Git initialization is not required.
-    let _ = Command::new("git")
-        .arg("init")
-        .stdin(Stdio::null())
-        .stderr(Stdio::null())
-        .status();
+    if init_git {
+        // Ignore any Git error because Git initialization is not required.
+        let _ = Command::new("git")
+            .arg("init")
+            .stdin(Stdio::null())
+            .stderr(Stdio::null())
+            .status();
+    }

-    println!(
+    writeln!(
+        stdout,
        "\n{}\n\n{}",
        "Initialization done ✓".green(),
        POST_INIT_MSG.bold(),
-    );
+    )?;

    Ok(())
 }

+const CARGO_LOCATE_PROJECT_ERR: &str = "Failed to run the command `cargo locate-project …`
+Did you already install Rust?
+Try running `cargo --version` to diagnose the problem.";
+
 const INIT_SOLUTION_FILE: &[u8] = b"fn main() {
    // DON'T EDIT THIS SOLUTION FILE!
    // It will be automatically filled after you finish the exercise.
 }
 ";

-const GITIGNORE: &[u8] = b".rustlings-state.txt
-solutions
-Cargo.lock
-target
-.vscode
+const GITIGNORE: &[u8] = b"Cargo.lock
+target/
+.vscode/
 ";

 pub const VS_CODE_EXTENSIONS_JSON: &[u8] = br#"{"recommendations":["rust-lang.rust-analyzer"]}"#;

-const CARGO_TOML_EXISTS_ERR: &str = "The current directory contains the file `Cargo.toml`.
+const IN_INITIALIZED_DIR_ERR: &str = "It looks like Rustlings is already initialized in this directory.

 If you already initialized Rustlings, run the command `rustlings` for instructions on getting started with the exercises.
-Otherwise, please run `rustlings init` again in another directory.";
+Otherwise, please run `rustlings init` again in a different directory.";

 const RUSTLINGS_DIR_ALREADY_EXISTS_ERR: &str =
    "A directory with the name `rustlings` already exists in the current directory.
--- a/src/list.rs
+++ b/src/list.rs
@@ -1,10 +1,13 @@
 use anyhow::Result;
-use crossterm::{
-    event::{self, Event, KeyCode, KeyEventKind},
-    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
-    ExecutableCommand,
+use ratatui::{
+    backend::CrosstermBackend,
+    crossterm::{
+        event::{self, Event, KeyCode, KeyEventKind},
+        terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+        ExecutableCommand,
+    },
+    Terminal,
 };
-use ratatui::{backend::CrosstermBackend, Terminal};
 use std::io;

 use crate::app_state::AppState;
@@ -24,7 +27,7 @@ pub fn list(app_state: &mut AppState) -> Result<()> {
    let mut ui_state = UiState::new(app_state);

    'outer: loop {
-        terminal.draw(|frame| ui_state.draw(frame).unwrap())?;
+        terminal.try_draw(|frame| ui_state.draw(frame).map_err(io::Error::other))?;

        let key = loop {
            match event::read()? {
--- a/src/list/state.rs
+++ b/src/list/state.rs
@@ -161,7 +161,7 @@ impl<'a> UiState<'a> {
    }

    pub fn draw(&mut self, frame: &mut Frame) -> Result<()> {
-        let area = frame.size();
+        let area = frame.area();

        frame.render_stateful_widget(
            &self.table,
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,16 +2,18 @@ use anyhow::{bail, Context, Result};
 use app_state::StateFileStatus;
 use clap::{Parser, Subcommand};
 use std::{
-    io::{self, BufRead, IsTerminal, StdoutLock, Write},
+    io::{self, IsTerminal, Write},
    path::Path,
    process::exit,
 };
+use term::{clear_terminal, press_enter_prompt};

 use self::{app_state::AppState, dev::DevCommands, info_file::InfoFile, watch::WatchExit};

 mod app_state;
 mod cargo_toml;
 mod cmd;
+mod collections;
 mod dev;
 mod embedded;
 mod exercise;
@@ -20,35 +22,11 @@ mod init;
 mod list;
 mod progress_bar;
 mod run;
+mod term;
 mod terminal_link;
 mod watch;

 const CURRENT_FORMAT_VERSION: u8 = 1;
-const DEBUG_PROFILE: bool = {
-    #[allow(unused_assignments, unused_mut)]
-    let mut debug_profile = false;
-
-    #[cfg(debug_assertions)]
-    {
-        debug_profile = true;
-    }
-
-    debug_profile
-};
-
-// The current directory is the official Rustligns repository.
-fn in_official_repo() -> bool {
-    Path::new("dev/rustlings-repo.txt").exists()
-}
-
-fn clear_terminal(stdout: &mut StdoutLock) -> io::Result<()> {
-    stdout.write_all(b"\x1b[H\x1b[2J\x1b[3J")
-}
-
-fn press_enter_prompt() -> io::Result<()> {
-    io::stdin().lock().read_until(b'\n', &mut Vec::new())?;
-    Ok(())
-}

 /// Rustlings is a collection of small exercises to get you used to writing and reading Rust code
 #[derive(Parser)]
@@ -89,24 +67,12 @@ enum Subcommands {
 fn main() -> Result<()> {
    let args = Args::parse();

-    if !DEBUG_PROFILE && in_official_repo() {
+    if cfg!(not(debug_assertions)) && Path::new("dev/rustlings-repo.txt").exists() {
        bail!("{OLD_METHOD_ERR}");
    }

    match args.command {
        Some(Subcommands::Init) => {
-            if DEBUG_PROFILE {
-                bail!("Disabled in the debug build");
-            }
-
-            {
-                let mut stdout = io::stdout().lock();
-                stdout.write_all(b"This command will create the directory `rustlings/` which will contain the exercises.\nPress ENTER to continue ")?;
-                stdout.flush()?;
-                press_enter_prompt()?;
-                stdout.write_all(b"\n")?;
-            }
-
            return init::init().context("Initialization failed");
        }
        Some(Subcommands::Dev(dev_command)) => return dev_command.run(),
@@ -136,11 +102,12 @@ fn main() -> Result<()> {
                let mut stdout = io::stdout().lock();
                clear_terminal(&mut stdout)?;

-                let welcome_message = welcome_message.trim();
+                let welcome_message = welcome_message.trim_ascii();
                write!(stdout, "{welcome_message}\n\nPress ENTER to continue ")?;
-                stdout.flush()?;
-                press_enter_prompt()?;
+                press_enter_prompt(&mut stdout)?;
                clear_terminal(&mut stdout)?;
+                // Flush to be able to show errors occurring before printing a newline to stdout.
+                stdout.flush()?;
            }
            StateFileStatus::Read => (),
        }
--- a/src/progress_bar.rs
+++ b/src/progress_bar.rs
@@ -14,7 +14,7 @@ const PROGRESS_EXCEEDS_MAX_ERR: &str =

 /// Terminal progress bar to be used when not using Ratataui.
 pub fn progress_bar(progress: u16, total: u16, line_width: u16) -> Result<String> {
-    use crossterm::style::Stylize;
+    use ratatui::crossterm::style::Stylize;

    if progress > total {
        bail!(PROGRESS_EXCEEDS_MAX_ERR);
--- a/src/run.rs
+++ b/src/run.rs
@@ -1,5 +1,5 @@
 use anyhow::{bail, Result};
-use crossterm::style::{style, Stylize};
+use ratatui::crossterm::style::{style, Stylize};
 use std::io::{self, Write};

 use crate::{
@@ -11,7 +11,7 @@ use crate::{
 pub fn run(app_state: &mut AppState) -> Result<()> {
    let exercise = app_state.current_exercise();
    let mut output = Vec::with_capacity(OUTPUT_CAPACITY);
-    let success = exercise.run_exercise(&mut output, app_state.target_dir())?;
+    let success = exercise.run_exercise(Some(&mut output), app_state.cmd_runner())?;

    let mut stdout = io::stdout().lock();
    stdout.write_all(&output)?;
--- a/src/term.rs
+++ b/src/term.rs
@@ -0,0 +1,12 @@
+use std::io::{self, BufRead, StdoutLock, Write};
+
+pub fn clear_terminal(stdout: &mut StdoutLock) -> io::Result<()> {
+    stdout.write_all(b"\x1b[H\x1b[2J\x1b[3J")
+}
+
+pub fn press_enter_prompt(stdout: &mut StdoutLock) -> io::Result<()> {
+    stdout.flush()?;
+    io::stdin().lock().read_until(b'\n', &mut Vec::new())?;
+    stdout.write_all(b"\n")?;
+    Ok(())
+}
--- a/src/watch.rs
+++ b/src/watch.rs
@@ -102,8 +102,7 @@ pub fn watch(
                watch_state.render()?;
            }
            WatchEvent::NotifyErr(e) => {
-                watch_state.into_writer().write_all(NOTIFY_ERR.as_bytes())?;
-                return Err(Error::from(e));
+                return Err(Error::from(e).context(NOTIFY_ERR));
            }
            WatchEvent::TerminalEventErr(e) => {
                return Err(Error::from(e).context("Terminal event listener failed"));
--- a/src/watch/state.rs
+++ b/src/watch/state.rs
@@ -1,5 +1,5 @@
 use anyhow::Result;
-use crossterm::{
+use ratatui::crossterm::{
    style::{style, Stylize},
    terminal,
 };
@@ -51,10 +51,15 @@ impl<'a> WatchState<'a> {
    pub fn run_current_exercise(&mut self) -> Result<()> {
        self.show_hint = false;

+        writeln!(
+            self.writer,
+            "\nChecking the exercise `{}`. Please wait…",
+            self.app_state.current_exercise().name,
+        )?;
        let success = self
            .app_state
            .current_exercise()
-            .run_exercise(&mut self.output, self.app_state.target_dir())?;
+            .run_exercise(Some(&mut self.output), self.app_state.cmd_runner())?;
        if success {
            self.done_status =
                if let Some(solution_path) = self.app_state.current_solution_path()? {
--- a/src/watch/terminal_event.rs
+++ b/src/watch/terminal_event.rs
@@ -1,4 +1,4 @@
-use crossterm::event::{self, Event, KeyCode, KeyEventKind, KeyModifiers};
+use ratatui::crossterm::event::{self, Event, KeyCode, KeyEventKind, KeyModifiers};
 use std::sync::mpsc::Sender;

 use super::WatchEvent;
--- a/tests/fixture/failure/Cargo.toml
+++ b/tests/fixture/failure/Cargo.toml
@@ -1,20 +0,0 @@
-[package]
-name = "failure"
-edition = "2021"
-publish = false
-
-[[bin]]
-name = "compFailure"
-path = "exercises/compFailure.rs"
-
-[[bin]]
-name = "compNoExercise"
-path = "exercises/compNoExercise.rs"
-
-[[bin]]
-name = "testFailure"
-path = "exercises/testFailure.rs"
-
-[[bin]]
-name = "testNotPassed"
-path = "exercises/testNotPassed.rs"
--- a/tests/fixture/failure/exercises/testFailure.rs
+++ b/tests/fixture/failure/exercises/testFailure.rs
@@ -1,6 +0,0 @@
-fn main() {}
-
-#[test]
-fn passing() {
-    asset!(true);
-}
--- a/tests/fixture/failure/exercises/testNotPassed.rs
+++ b/tests/fixture/failure/exercises/testNotPassed.rs
@@ -1,6 +0,0 @@
-fn main() {}
-
-#[test]
-fn not_passing() {
-    assert!(false);
-}
--- a/tests/fixture/failure/info.toml
+++ b/tests/fixture/failure/info.toml
@@ -1,10 +0,0 @@
-format_version = 1
-
-[[exercises]]
-name = "compFailure"
-test = false
-hint = ""
-
-[[exercises]]
-name = "testFailure"
-hint = "Hello!"
--- a/tests/fixture/state/Cargo.toml
+++ b/tests/fixture/state/Cargo.toml
@@ -1,16 +0,0 @@
-[package]
-name = "state"
-edition = "2021"
-publish = false
-
-[[bin]]
-name = "pending_exercise"
-path = "exercises/pending_exercise.rs"
-
-[[bin]]
-name = "pending_test_exercise"
-path = "exercises/pending_test_exercise.rs"
-
-[[bin]]
-name = "finished_exercise"
-path = "exercises/finished_exercise.rs"
--- a/tests/fixture/state/exercises/pending_exercise.rs
+++ b/tests/fixture/state/exercises/pending_exercise.rs
@@ -1 +0,0 @@
-fn main() {}
--- a/tests/fixture/state/exercises/pending_test_exercise.rs
+++ b/tests/fixture/state/exercises/pending_test_exercise.rs
@@ -1,4 +0,0 @@
-fn main() {}
-
-#[test]
-fn it_works() {}
--- a/tests/fixture/state/info.toml
+++ b/tests/fixture/state/info.toml
@@ -1,15 +0,0 @@
-format_version = 1
-
-[[exercises]]
-name = "pending_exercise"
-test = false
-hint = """"""
-
-[[exercises]]
-name = "pending_test_exercise"
-hint = """"""
-
-[[exercises]]
-name = "finished_exercise"
-test = false
-hint = """"""
--- a/tests/fixture/success/Cargo.toml
+++ b/tests/fixture/success/Cargo.toml
@@ -1,12 +0,0 @@
-[package]
-name = "success"
-edition = "2021"
-publish = false
-
-[[bin]]
-name = "compSuccess"
-path = "exercises/compSuccess.rs"
-
-[[bin]]
-name = "testSuccess"
-path = "exercises/testSuccess.rs"
--- a/tests/fixture/success/exercises/compSuccess.rs
+++ b/tests/fixture/success/exercises/compSuccess.rs
@@ -1 +0,0 @@
-fn main() {}
--- a/tests/fixture/success/exercises/testSuccess.rs
+++ b/tests/fixture/success/exercises/testSuccess.rs
@@ -1,7 +0,0 @@
-fn main() {}
-
-#[test]
-fn passing() {
-    println!("THIS TEST TOO SHALL PASS");
-    assert!(true);
-}
--- a/tests/fixture/success/info.toml
+++ b/tests/fixture/success/info.toml
@@ -1,10 +0,0 @@
-format_version = 1
-
-[[exercises]]
-name = "compSuccess"
-test = false
-hint = """"""
-
-[[exercises]]
-name = "testSuccess"
-hint = """"""
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -1,134 +1,182 @@
-use assert_cmd::prelude::*;
-use std::process::Command;
+use std::{
+    env::{self, consts::EXE_SUFFIX},
+    process::{Command, Stdio},
+    str::from_utf8,
+};

-#[test]
-fn fails_when_in_wrong_dir() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .current_dir("tests/")
-        .assert()
-        .code(1);
+enum Output<'a> {
+    FullStdout(&'a str),
+    PartialStdout(&'a str),
+    PartialStderr(&'a str),
+}
+
+use Output::*;
+
+#[derive(Default)]
+struct Cmd<'a> {
+    current_dir: Option<&'a str>,
+    args: &'a [&'a str],
+    output: Option<Output<'a>>,
+}
+
+impl<'a> Cmd<'a> {
+    #[inline]
+    fn current_dir(&mut self, current_dir: &'a str) -> &mut Self {
+        self.current_dir = Some(current_dir);
+        self
+    }
+
+    #[inline]
+    fn args(&mut self, args: &'a [&'a str]) -> &mut Self {
+        self.args = args;
+        self
+    }
+
+    #[inline]
+    fn output(&mut self, output: Output<'a>) -> &mut Self {
+        self.output = Some(output);
+        self
+    }
+
+    fn assert(&self, success: bool) {
+        let rustlings_bin = {
+            let mut path = env::current_exe().unwrap();
+            // Pop test binary name
+            path.pop();
+            // Pop `/deps`
+            path.pop();
+
+            path.push("rustlings");
+            let mut path = path.into_os_string();
+            path.push(EXE_SUFFIX);
+            path
+        };
+
+        let mut cmd = Command::new(rustlings_bin);
+
+        if let Some(current_dir) = self.current_dir {
+            cmd.current_dir(current_dir);
+        }
+
+        cmd.args(self.args).stdin(Stdio::null());
+
+        let status = match self.output {
+            None => cmd
+                .stdout(Stdio::null())
+                .stderr(Stdio::null())
+                .status()
+                .unwrap(),
+            Some(FullStdout(stdout)) => {
+                let output = cmd.stderr(Stdio::null()).output().unwrap();
+                assert_eq!(from_utf8(&output.stdout).unwrap(), stdout);
+                output.status
+            }
+            Some(PartialStdout(stdout)) => {
+                let output = cmd.stderr(Stdio::null()).output().unwrap();
+                assert!(from_utf8(&output.stdout).unwrap().contains(stdout));
+                output.status
+            }
+            Some(PartialStderr(stderr)) => {
+                let output = cmd.stdout(Stdio::null()).output().unwrap();
+                assert!(from_utf8(&output.stderr).unwrap().contains(stderr));
+                output.status
+            }
+        };
+
+        assert_eq!(status.success(), success, "{cmd:?}");
+    }
+
+    #[inline]
+    fn success(&self) {
+        self.assert(true);
+    }
+
+    #[inline]
+    fn fail(&self) {
+        self.assert(false);
+    }
 }

 #[test]
-fn run_single_compile_success() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "compSuccess"])
-        .current_dir("tests/fixture/success/")
-        .assert()
+fn run_compilation_success() {
+    Cmd::default()
+        .current_dir("tests/test_exercises")
+        .args(&["run", "compilation_success"])
        .success();
 }

 #[test]
-fn run_single_compile_failure() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "compFailure"])
-        .current_dir("tests/fixture/failure/")
-        .assert()
-        .code(1);
+fn run_compilation_failure() {
+    Cmd::default()
+        .current_dir("tests/test_exercises")
+        .args(&["run", "compilation_failure"])
+        .fail();
 }

 #[test]
-fn run_single_test_success() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "testSuccess"])
-        .current_dir("tests/fixture/success/")
-        .assert()
+fn run_test_success() {
+    Cmd::default()
+        .current_dir("tests/test_exercises")
+        .args(&["run", "test_success"])
+        .output(PartialStdout("\nOutput from `main` function\n"))
        .success();
 }

 #[test]
-fn run_single_test_failure() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "testFailure"])
-        .current_dir("tests/fixture/failure/")
-        .assert()
-        .code(1);
+fn run_test_failure() {
+    Cmd::default()
+        .current_dir("tests/test_exercises")
+        .args(&["run", "test_failure"])
+        .fail();
 }

 #[test]
-fn run_single_test_not_passed() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "testNotPassed.rs"])
-        .current_dir("tests/fixture/failure/")
-        .assert()
-        .code(1);
+fn run_exercise_not_in_info() {
+    Cmd::default()
+        .current_dir("tests/test_exercises")
+        .args(&["run", "not_in_info"])
+        .fail();
 }

 #[test]
-fn run_single_test_no_exercise() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "compNoExercise.rs"])
-        .current_dir("tests/fixture/failure")
-        .assert()
-        .code(1);
+fn reset_without_exercise_name() {
+    Cmd::default().args(&["reset"]).fail();
 }

 #[test]
-fn reset_single_exercise() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["reset", "intro1"])
-        .assert()
-        .code(0);
+fn hint() {
+    Cmd::default()
+        .current_dir("tests/test_exercises")
+        .args(&["hint", "test_failure"])
+        .output(FullStdout("The answer to everything: 42\n"))
+        .success();
 }

 #[test]
-fn reset_no_exercise() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .arg("reset")
-        .assert()
-        .code(2)
-        .stderr(predicates::str::contains(
-            "required arguments were not provided",
-        ));
-}
+fn init() {
+    let test_dir = tempfile::TempDir::new().unwrap();
+    let test_dir = test_dir.path().to_str().unwrap();

-#[test]
-fn get_hint_for_single_test() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["hint", "testFailure"])
-        .current_dir("tests/fixture/failure")
-        .assert()
-        .code(0)
-        .stdout("Hello!\n");
-}
+    Cmd::default().current_dir(test_dir).fail();

-#[test]
-fn run_compile_exercise_does_not_prompt() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "pending_exercise"])
-        .current_dir("tests/fixture/state")
-        .assert()
-        .code(0);
-}
+    Cmd::default()
+        .current_dir(test_dir)
+        .args(&["init"])
+        .success();

-#[test]
-fn run_test_exercise_does_not_prompt() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "pending_test_exercise"])
-        .current_dir("tests/fixture/state")
-        .assert()
-        .code(0);
-}
+    // Running `init` after a successful initialization.
+    Cmd::default()
+        .current_dir(test_dir)
+        .args(&["init"])
+        .output(PartialStderr("`cd rustlings`"))
+        .fail();

-#[test]
-fn run_single_test_success_with_output() {
-    Command::cargo_bin("rustlings")
-        .unwrap()
-        .args(["run", "testSuccess"])
-        .current_dir("tests/fixture/success/")
-        .assert()
-        .code(0)
-        .stdout(predicates::str::contains("THIS TEST TOO SHALL PASS"));
+    let initialized_dir = format!("{test_dir}/rustlings");
+
+    // Running `init` in the initialized directory.
+    Cmd::default()
+        .current_dir(&initialized_dir)
+        .args(&["init"])
+        .output(PartialStderr("already initialized"))
+        .fail();
 }
--- a/tests/test_exercises/dev/Cargo.toml
+++ b/tests/test_exercises/dev/Cargo.toml
@@ -0,0 +1,11 @@
+bin = [
+  { name = "compilation_success", path = "../exercises/compilation_success.rs" },
+  { name = "compilation_failure", path = "../exercises/compilation_failure.rs" },
+  { name = "test_success", path = "../exercises/test_success.rs" },
+  { name = "test_failure", path = "../exercises/test_failure.rs" },
+]
+
+[package]
+name = "test_exercises"
+edition = "2021"
+publish = false
--- a/tests/test_exercises/exercises/compilation_failure.rs
+++ b/tests/test_exercises/exercises/compilation_failure.rs
--- a/tests/test_exercises/exercises/compilation_success.rs
+++ b/tests/test_exercises/exercises/compilation_success.rs
--- a/tests/fixture/state/exercises/finished_exercise.rs
+++ b/tests/fixture/state/exercises/finished_exercise.rs
--- a/tests/test_exercises/exercises/test_failure.rs
+++ b/tests/test_exercises/exercises/test_failure.rs
@@ -0,0 +1,9 @@
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn fails() {
+        assert!(false);
+    }
+}
--- a/tests/test_exercises/exercises/test_success.rs
+++ b/tests/test_exercises/exercises/test_success.rs
@@ -0,0 +1,9 @@
+fn main() {
+    println!("Output from `main` function");
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn passes() {}
+}
--- a/tests/test_exercises/info.toml
+++ b/tests/test_exercises/info.toml
@@ -0,0 +1,19 @@
+format_version = 1
+
+[[exercises]]
+name = "compilation_success"
+test = false
+hint = ""
+
+[[exercises]]
+name = "compilation_failure"
+test = false
+hint = ""
+
+[[exercises]]
+name = "test_success"
+hint = ""
+
+[[exercises]]
+name = "test_failure"
+hint = "The answer to everything: 42"
Author	SHA1	Message	Date
mo8it	4472d50eba	chore: Release	2024-08-09 11:52:31 +02:00
mo8it	a1d5702ba0	Ready for publish	2024-08-09 11:51:56 +02:00
mo8it	52a231ce2f	Update Ratatui	2024-08-09 02:17:01 +02:00
mo8it	16af981772	Hide stderr of `cargo locate-project`	2024-08-09 01:27:31 +02:00
mo8it	fc141b8dfc	Put Cargo.toml in ``	2024-08-09 01:16:45 +02:00
mo8it	82ebd29ff6	Add a special confirmation for initialization in a workspace	2024-08-09 01:14:08 +02:00
mo8it	f5737b5a49	Fix typos	2024-08-09 01:08:52 +02:00
mo8it	55e68d2c63	Update deps	2024-08-09 01:06:27 +02:00
mo8it	479f45da9b	test_dir is a str anyway	2024-08-09 01:05:44 +02:00
mo8it	140c4e4812	Improve initialization in a Cargo workspace	2024-08-09 00:49:30 +02:00
mo8it	337460d299	Check the status of the `cargo metadata` command	2024-08-09 00:12:49 +02:00
mo8it	e41c3a7c92	Use fixed seeds with ahash	2024-08-08 23:48:54 +02:00
mo8it	1b9faa4d61	Update CHANGELOG	2024-08-08 23:48:54 +02:00
Mo	9f9a754a64	Merge pull request #2076 from senekor/remo/snryotxotoxv Improve initialization in workspace	2024-08-08 23:48:09 +02:00
Mo	f7b0cfe8d1	Merge pull request #2075 from senekor/remo/swzqnkxqzutw Replace hashbrown with ahash	2024-08-08 23:12:43 +02:00
mo8it	4ce8667b9d	Show the exercise name in the waiting message	2024-08-08 22:48:53 +02:00
mo8it	0785b24192	Show a message before running the exercise	2024-08-08 22:41:41 +02:00
mo8it	34f02cf83d	Attach error message as context	2024-08-08 22:37:56 +02:00
Remo Senekowitsch	8b43d79257	Fix integration tests	2024-08-08 14:08:06 +02:00
Remo Senekowitsch	dc086c6bf1	Improve initialization in workspace - Detect if we are in a cargo project more reliably. (e.g. if `rustlings init` is run in the `src/` directory) - Refuse to initialize rustlings in a non-workspace cargo project. - Automatically populate the `workspace.members` field if `rustlings init` is run in a workspace. This may be considered risky, as there is no guarantee that's what the user wanted to do. However, it is consistent with the behavior of `cargo new`. Also, newcomers to Rust are unlikely to accidentally be in a cargo workspace, as they won't know how to create one in the first place. The use case for initialization in a workspace is when a workshop organizer wants to use rustlings alongside other exerices and provide a single repository with everything in one place.	2024-08-08 13:34:27 +02:00
Remo Senekowitsch	dc0ffbe16e	Replace hashbrown with ahash hashbrown is already used in the standard library, but we want the improved performance of the different hash algorithm. Using ahash directly conveys this intent more clearly.	2024-08-08 11:12:17 +02:00
mo8it	8df66f7991	Allow initialization in a workspace	2024-08-08 02:45:18 +02:00
mo8it	39580381fa	rust-analyzer problem isn't fixed :(	2024-08-08 01:48:57 +02:00
mo8it	06a0f278e5	Don't recommend the builtin VS-Code terminal because it can't clear scrollback	2024-08-08 01:35:47 +02:00
mo8it	fd97470f35	Adapt type name in hint	2024-08-08 00:42:26 +02:00
mo8it	11fc3f1e56	Fix errors not being shown after the welcome message	2024-08-08 00:41:12 +02:00
mo8it	693bb708b2	Add README to the solutions dir	2024-08-08 00:41:12 +02:00
mo8it	97719fe8da	Remove state file and solutions dir from .gitignore	2024-08-08 00:41:12 +02:00
mo8it	4933ace50b	Add `panic = "abort"` for exercises	2024-08-08 00:41:12 +02:00
mo8it	81bf0a6430	Remove redundant rustfmt check for solutions	2024-08-08 00:41:12 +02:00
mo8it	24aed1b14e	Update CHANGELOG	2024-08-08 00:41:12 +02:00
Mo	09c3ac02f8	Merge pull request #2062 from jimbo5922/jimbo5922-fix-hashmap3-struct-name update struct name in hashmap3	2024-08-08 00:40:51 +02:00
Mo	45a39585b3	Merge pull request #2066 from matthewjnield/main chore: Fix snakecase convention in errors6.rs	2024-08-08 00:36:46 +02:00
mo8it	286a455fa9	Avoid using `RUSTFLAGS` to not trigger rebuilding, especially in rust-analyzer	2024-08-07 23:35:50 +02:00
mo8it	bdf4960b6a	Fix exercise name shift in exercise check	2024-08-07 23:25:22 +02:00
mo8it	13124aafe3	Update deps	2024-08-05 03:15:43 +02:00
Matt Nield	2128be8b28	chore: Fix snakecase convention in errors6.rs Exercise errors6.rs prompts the user to add a method named `from_parseint`. This commit changes the method name to the corrected snakecase format, `from_parse_int`.	2024-08-04 02:36:45 -04:00
mo8it	175294fa5d	Add `rust-version`	2024-08-02 16:40:06 +02:00
mo8it	5016c7cf7c	Use `trim_ascii` instead of `trim`	2024-08-02 16:28:05 +02:00
mo8it	1468206052	Stop on first exercise solved	2024-08-02 15:54:14 +02:00
mo8it	d1ff4b5cf0	Remove newline	2024-08-01 19:19:25 +02:00
mo8it	700a065abd	Fix rustfmt option	2024-08-01 19:19:14 +02:00
mo8it	3fc462f90f	Fix tests	2024-08-01 19:17:40 +02:00
mo8it	65a8f6bb4b	Run rustfmt on solutions in `dev check`	2024-08-01 19:14:09 +02:00
mo8it	e0f0944bff	Refactor check_solutions	2024-08-01 15:53:32 +02:00
mo8it	c7590dd752	Improve the runner	2024-08-01 15:23:54 +02:00
mo8it	33a5680328	Hide `cargo build` warnings if there is no output	2024-08-01 11:28:26 +02:00
mo8it	455d87cadd	Fix capacity	2024-08-01 11:26:30 +02:00
Yudai Kawabuchi	e65ae09789	fix format	2024-08-01 09:55:25 +09:00
Yudai Kawabuchi	dacdce1ea2	fix: update struct name in hashmap3	2024-08-01 09:47:50 +09:00
mo8it	766f3c50ec	Add hint to run `dev check` again after `dev update`	2024-08-01 01:07:56 +02:00
mo8it	802b97b2ed	Set stdin to null when running the binary of an exercise	2024-08-01 01:07:31 +02:00
mo8it	2ad408f2b8	Update deps	2024-07-31 18:54:24 +02:00
mo8it	c8fddd8f62	Add Github profile links for every author	2024-07-31 18:53:25 +02:00
mo8it	74fab994e2	Make the output optional	2024-07-28 20:30:23 +02:00
mo8it	3a99542f73	Run the final check in parallel	2024-07-28 17:39:46 +02:00
mo8it	2ae9f3555b	Update deps	2024-07-28 13:30:31 +02:00
mo8it	1937b4bf66	Use the rexported crossterm from ratatui	2024-07-25 16:26:48 +02:00
mo8it	8beb290842	Test initialization	2024-07-25 16:14:38 +02:00
mo8it	8fec5155c7	Clean up tests	2024-07-25 15:12:14 +02:00
mo8it	3f49decce9	Remove assert_cmd and predicates	2024-07-25 14:34:43 +02:00
mo8it	e2492f65a0	Update deps	2024-07-25 12:51:44 +02:00
mo8it	5116a812fb	tests3: Fix panic message	2024-07-22 12:02:59 +02:00
mo8it	82409c060f	Update deps	2024-07-22 12:01:41 +02:00
mo8it	183ed3f88f	Update dep	2024-07-17 14:33:29 +02:00
mo8it	447ac3c40b	strings3: Improve hint	2024-07-17 14:32:45 +02:00
Mo	96f96927da	Merge pull request #2050 from yapjiahong/main doc: enchane string3 exercise hint	2024-07-17 14:31:17 +02:00
yapjiahong	2c79e29483	doc: enchane string3 exercise hint	2024-07-17 00:43:42 +08:00
mo8it	362473dde0	Sync exercise and solution	2024-07-16 18:21:07 +02:00
Mo	8339682112	Merge pull request #2049 from Vexcited/patch-1 fix: Lyche becomes Lychee	2024-07-16 18:18:46 +02:00
Mikkel ALMONTE--RINGAUD	3f06d767b5	fix: Lyche becomes Lychee Small typo.	2024-07-16 17:20:26 +02:00
mo8it	2854dc9ab3	Update CI and release hook	2024-07-13 12:32:23 +02:00
mo8it	516fcf9168	Update section	2024-07-13 12:07:52 +02:00
mo8it	12d1971b0d	Update section about command not found	2024-07-13 12:02:39 +02:00
mo8it	3e09e509d6	Add section about rustlings not found	2024-07-13 12:00:22 +02:00
mo8it	99fb11cc72	Update syn	2024-07-13 11:53:59 +02:00
mo8it	d176ddd27e	Improve TODO comment	2024-07-12 16:29:41 +02:00