2.2.1

feat: Add clippy lints

This is a feature PR which adds the possiblity to create clippy exercises.

Clippy has many awesome linting rules, which can give a deeper understanding about the Rust programming language, therefor I made this PR.

.gitignore

@@ -2,3 +2,6 @@
 target/
 **/*.rs.bk
 .DS_Store
+*.pdb
+exercises/clippy/Cargo.toml
+exercises/clippy/Cargo.lock

CHANGELOG.md

@@ -1,3 +1,14 @@
+<a name="2.2.1"></a>
+### 2.2.1 (2020-02-27)
+
+#### Bug Fixes
+
+*   Re-add cloning the repo to install scripts ([3d9b03c5](https://github.com/rust-lang/rustlings/commit/3d9b03c52b8dc51b140757f6fd25ad87b5782ef5))
+
+#### Features
+
+*   Add clippy lints (#269) ([1e2fd9c9](https://github.com/rust-lang/rustlings/commit/1e2fd9c92f8cd6e389525ca1a999fca4c90b5921))
+
 <a name="2.2.0"></a>
 ## 2.2.0 (2020-02-25)
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rustlings"
-version = "2.2.0"
+version = "2.2.1"
 authors = ["Marisa <mokou@posteo.de>", "Carol (Nichols || Goulding) <carol.nichols@gmail.com"]
 edition = "2018"
 

README.md

@@ -54,7 +54,7 @@ Basically: Clone the repository, checkout to the latest tag, run `cargo install`
 ```bash
 git clone https://github.com/rust-lang/rustlings
 cd rustlings
-git checkout tags/2.2.0 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
+git checkout tags/2.2.1 # or whatever the latest version is (find out at https://github.com/rust-lang/rustlings/releases/latest)
 cargo install --force --path .
 ```
 

exercises/clippy/README.md

@@ -0,0 +1,8 @@
+### Clippy
+
+The Clippy tool is a collection of lints to analyze your code so you can catch common mistakes and improve your Rust code.
+
+If you used the installation script for Rustlings, Clippy should be already installed.
+If not you can install it manually via `rustup component add clippy`.
+
+For more information about Clippy lints, please see [their documentation page](https://rust-lang.github.io/rust-clippy/master/).

exercises/clippy/clippy1.rs

@@ -0,0 +1,15 @@
+// clippy1.rs
+// The Clippy tool is a collection of lints to analyze your code
+// so you can catch common mistakes and improve your Rust code.
+//
+// Execute `rustlings hint clippy1` for hints :)
+
+// I AM NOT DONE
+
+fn main() {
+    let x = 1.2331f64;
+    let y = 1.2332f64;
+    if y != x {
+        println!("Success!");
+    }
+}

exercises/clippy/clippy2.rs

@@ -0,0 +1,13 @@
+// clippy2.rs
+// Make me compile! Execute `rustlings hint clippy2` for hints :)
+
+// I AM NOT DONE
+
+fn main() {
+    let mut res = 42;
+    let option = Some(12);
+    for x in option {
+        res += x;
+    }
+    println!("{}", res);
+}

info.toml

@@ -529,6 +529,22 @@ hint = """
 It should be doing some checking, returning an `Err` result if those checks fail, and only
 returning an `Ok` result if those checks determine that everything is... okay :)"""
 
+#  CLIPPY
+
+[[exercises]]
+name = "clippy1"
+path = "exercises/clippy/clippy1.rs"
+mode = "clippy"
+hint = """
+Floating point calculations are usually imprecise, so asking if two values are exactly equal is asking for trouble"""
+
+[[exercises]]
+name = "clippy2"
+path = "exercises/clippy/clippy2.rs"
+mode = "clippy"
+hint = """
+`for` loops over Option values are more clearly expressed as an `if let`"""
+
 # STANDARD LIBRARY TYPES
 
 [[exercises]]

install.ps1

@@ -72,6 +72,7 @@ if (!($LASTEXITCODE -eq 0)) {
 # but anyone running pwsh 5 will have to pass the argument.
 $version = Invoke-WebRequest -UseBasicParsing https://api.github.com/repos/rust-lang/rustlings/releases/latest `
     | ConvertFrom-Json | Select-Object -ExpandProperty tag_name
+
 Write-Host "Checking out version $version..."
 Set-Location $path
 git checkout -q tags/$version
@@ -82,4 +83,12 @@ if (!(Get-Command rustlings -ErrorAction SilentlyContinue)) {
     Write-Host "WARNING: Please check that you have '~/.cargo/bin' in your PATH environment variable!"
 }
 
+# Checking whether Clippy is installed.
+# Due to a bug in Cargo, this must be done with Rustup: https://github.com/rust-lang/rustup/issues/1514
+$clippy = (rustup component list | Select-String "clippy" | Select-String "installed") | Out-String
+if (!$clippy) {
+    Write-Host "Installing the 'cargo-clippy' executable..."
+    rustup component add clippy
+}
+
 Write-Host "All done! Run 'rustlings' to get started."

install.sh

@@ -87,6 +87,8 @@ echo "Cloning Rustlings at $Path..."
 git clone -q https://github.com/rust-lang/rustlings $Path
 
 Version=$(curl -s https://api.github.com/repos/rust-lang/rustlings/releases/latest | python -c "import json,sys;obj=json.load(sys.stdin);print(obj['tag_name']);")
+CargoBin="${CARGO_HOME:-$HOME/.cargo}/bin"
+
 echo "Checking out version $Version..."
 cd $Path
 git checkout -q tags/$Version
@@ -96,7 +98,16 @@ cargo install --force --path .
 
 if ! [ -x "$(command -v rustlings)" ]
 then
-    echo "WARNING: Please check that you have '~/.cargo/bin' in your PATH environment variable!"
+    echo "WARNING: Please check that you have '$CargoBin' in your PATH environment variable!"
+fi
+
+# Checking whether Clippy is installed.
+# Due to a bug in Cargo, this must be done with Rustup: https://github.com/rust-lang/rustup/issues/1514
+Clippy=$(rustup component list | grep "clippy" | grep "installed")
+if [ -z "$Clippy" ]
+then
+    echo "Installing the 'cargo-clippy' executable..."
+    rustup component add clippy
 fi
 
 echo "All done! Run 'rustlings' to get started."

src/exercise.rs

@@ -1,14 +1,15 @@
 use regex::Regex;
 use serde::Deserialize;
 use std::fmt::{self, Display, Formatter};
-use std::fs::{remove_file, File};
+use std::fs::{self, remove_file, File};
 use std::io::Read;
 use std::path::PathBuf;
-use std::process::{self, Command, Output};
+use std::process::{self, Command};
 
 const RUSTC_COLOR_ARGS: &[&str] = &["--color", "always"];
 const I_AM_DONE_REGEX: &str = r"(?m)^\s*///?\s*I\s+AM\s+NOT\s+DONE";
 const CONTEXT: usize = 2;
+const CLIPPY_CARGO_TOML_PATH: &str = "./exercises/clippy/Cargo.toml";
 
 fn temp_file() -> String {
     format!("./temp_{}", process::id())
@@ -19,6 +20,7 @@ fn temp_file() -> String {
 pub enum Mode {
     Compile,
     Test,
+    Clippy,
 }
 
 #[derive(Deserialize)]
@@ -47,9 +49,34 @@ pub struct ContextLine {
     pub important: bool,
 }
 
+pub struct CompiledExercise<'a> {
+    exercise: &'a Exercise,
+    _handle: FileHandle,
+}
+
+impl<'a> CompiledExercise<'a> {
+    pub fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
+        self.exercise.run()
+    }
+}
+
+#[derive(Debug)]
+pub struct ExerciseOutput {
+    pub stdout: String,
+    pub stderr: String,
+}
+
+struct FileHandle;
+
+impl Drop for FileHandle {
+    fn drop(&mut self) {
+        clean();
+    }
+}
+
 impl Exercise {
-    pub fn compile(&self) -> Output {
-        match self.mode {
+    pub fn compile(&self) -> Result<CompiledExercise, ExerciseOutput> {
+        let cmd = match self.mode {
             Mode::Compile => Command::new("rustc")
                 .args(&[self.path.to_str().unwrap(), "-o", &temp_file()])
                 .args(RUSTC_COLOR_ARGS)
@@ -58,18 +85,66 @@ impl Exercise {
                 .args(&["--test", self.path.to_str().unwrap(), "-o", &temp_file()])
                 .args(RUSTC_COLOR_ARGS)
                 .output(),
+            Mode::Clippy => {
+                let cargo_toml = format!(
+                    r#"[package]
+name = "{}"
+version = "0.0.1"
+edition = "2018"
+[[bin]]
+name = "{}"
+path = "{}.rs""#,
+                    self.name, self.name, self.name
+                );
+                fs::write(CLIPPY_CARGO_TOML_PATH, cargo_toml)
+                    .expect("Failed to write 📎 Clippy 📎 Cargo.toml file.");
+                // Due to an issue with Clippy, a cargo clean is required to catch all lints.
+                // See https://github.com/rust-lang/rust-clippy/issues/2604
+                // This is already fixed on master branch. See this issue to track merging into Cargo:
+                // https://github.com/rust-lang/rust-clippy/issues/3837
+                Command::new("cargo")
+                    .args(&["clean", "--manifest-path", CLIPPY_CARGO_TOML_PATH])
+                    .args(RUSTC_COLOR_ARGS)
+                    .output()
+                    .expect("Failed to run 'cargo clean'");
+                Command::new("cargo")
+                    .args(&["clippy", "--manifest-path", CLIPPY_CARGO_TOML_PATH])
+                    .args(RUSTC_COLOR_ARGS)
+                    .args(&["--", "-D", "warnings"])
+                    .output()
+            }
+        }
+        .expect("Failed to run 'compile' command.");
+
+        if cmd.status.success() {
+            Ok(CompiledExercise {
+                exercise: &self,
+                _handle: FileHandle,
+            })
+        } else {
+            clean();
+            Err(ExerciseOutput {
+                stdout: String::from_utf8_lossy(&cmd.stdout).to_string(),
+                stderr: String::from_utf8_lossy(&cmd.stderr).to_string(),
+            })
         }
-        .expect("Failed to run 'compile' command.")
     }
 
-    pub fn run(&self) -> Output {
-        Command::new(&temp_file())
+    fn run(&self) -> Result<ExerciseOutput, ExerciseOutput> {
+        let cmd = Command::new(&temp_file())
             .output()
-            .expect("Failed to run 'run' command")
-    }
+            .expect("Failed to run 'run' command");
 
-    pub fn clean(&self) {
-        let _ignored = remove_file(&temp_file());
+        let output = ExerciseOutput {
+            stdout: String::from_utf8_lossy(&cmd.stdout).to_string(),
+            stderr: String::from_utf8_lossy(&cmd.stderr).to_string(),
+        };
+
+        if cmd.status.success() {
+            Ok(output)
+        } else {
+            Err(output)
+        }
     }
 
     pub fn state(&self) -> State {
@@ -121,6 +196,10 @@ impl Display for Exercise {
     }
 }
 
+fn clean() {
+    let _ignored = remove_file(&temp_file());
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -131,11 +210,12 @@ mod test {
         File::create(&temp_file()).unwrap();
         let exercise = Exercise {
             name: String::from("example"),
-            path: PathBuf::from("example.rs"),
-            mode: Mode::Test,
+            path: PathBuf::from("tests/fixture/state/pending_exercise.rs"),
+            mode: Mode::Compile,
             hint: String::from(""),
         };
-        exercise.clean();
+        let compiled = exercise.compile().unwrap();
+        drop(compiled);
         assert!(!Path::new(&temp_file()).exists());
     }
 

src/main.rs

@@ -15,6 +15,9 @@ use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
 
+#[macro_use]
+mod ui;
+
 mod exercise;
 mod run;
 mod verify;

src/run.rs

@@ -1,52 +1,51 @@
 use crate::exercise::{Exercise, Mode};
 use crate::verify::test;
-use console::{style, Emoji};
 use indicatif::ProgressBar;
 
 pub fn run(exercise: &Exercise) -> Result<(), ()> {
     match exercise.mode {
         Mode::Test => test(exercise)?,
         Mode::Compile => compile_and_run(exercise)?,
+        Mode::Clippy => compile_and_run(exercise)?,
     }
     Ok(())
 }
 
-pub fn compile_and_run(exercise: &Exercise) -> Result<(), ()> {
+fn compile_and_run(exercise: &Exercise) -> Result<(), ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Compiling {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
 
-    let compilecmd = exercise.compile();
+    let compilation_result = exercise.compile();
+    let compilation = match compilation_result {
+        Ok(compilation) => compilation,
+        Err(output) => {
+            progress_bar.finish_and_clear();
+            warn!(
+                "Compilation of {} failed!, Compiler error message:\n",
+                exercise
+            );
+            println!("{}", output.stderr);
+            return Err(());
+        }
+    };
+
     progress_bar.set_message(format!("Running {}...", exercise).as_str());
-    if compilecmd.status.success() {
-        let runcmd = exercise.run();
-        progress_bar.finish_and_clear();
+    let result = compilation.run();
+    progress_bar.finish_and_clear();
 
-        if runcmd.status.success() {
-            println!("{}", String::from_utf8_lossy(&runcmd.stdout));
-            let formatstr = format!("{} Successfully ran {}", Emoji("✅", "✓"), exercise);
-            println!("{}", style(formatstr).green());
-            exercise.clean();
+    match result {
+        Ok(output) => {
+            println!("{}", output.stdout);
+            success!("Successfully ran {}", exercise);
             Ok(())
-        } else {
-            println!("{}", String::from_utf8_lossy(&runcmd.stdout));
-            println!("{}", String::from_utf8_lossy(&runcmd.stderr));
+        }
+        Err(output) => {
+            println!("{}", output.stdout);
+            println!("{}", output.stderr);
 
-            let formatstr = format!("{} Ran {} with errors", Emoji("⚠️ ", "!"), exercise);
-            println!("{}", style(formatstr).red());
-            exercise.clean();
+            warn!("Ran {} with errors", exercise);
             Err(())
         }
-    } else {
-        progress_bar.finish_and_clear();
-        let formatstr = format!(
-            "{} Compilation of {} failed! Compiler error message:\n",
-            Emoji("⚠️ ", "!"),
-            exercise
-        );
-        println!("{}", style(formatstr).red());
-        println!("{}", String::from_utf8_lossy(&compilecmd.stderr));
-        exercise.clean();
-        Err(())
     }
 }

src/ui.rs

@@ -0,0 +1,23 @@
+macro_rules! warn {
+    ($fmt:literal, $ex:expr) => {{
+        use console::{style, Emoji};
+        let formatstr = format!($fmt, $ex);
+        println!(
+            "{} {}",
+            style(Emoji("⚠️ ", "!")).red(),
+            style(formatstr).red()
+        );
+    }};
+}
+
+macro_rules! success {
+    ($fmt:literal, $ex:expr) => {{
+        use console::{style, Emoji};
+        let formatstr = format!($fmt, $ex);
+        println!(
+            "{} {}",
+            style(Emoji("✅", "✓")).green(),
+            style(formatstr).green()
+        );
+    }};
+}

src/verify.rs

@@ -1,12 +1,13 @@
 use crate::exercise::{Exercise, Mode, State};
-use console::{style, Emoji};
+use console::style;
 use indicatif::ProgressBar;
 
 pub fn verify<'a>(start_at: impl IntoIterator<Item = &'a Exercise>) -> Result<(), &'a Exercise> {
     for exercise in start_at {
         let compile_result = match exercise.mode {
-            Mode::Test => compile_and_test_interactively(&exercise),
+            Mode::Test => compile_and_test(&exercise, RunMode::Interactive),
             Mode::Compile => compile_only(&exercise),
+            Mode::Clippy => compile_only(&exercise),
         };
         if !compile_result.unwrap_or(false) {
             return Err(exercise);
@@ -15,8 +16,13 @@ pub fn verify<'a>(start_at: impl IntoIterator<Item = &'a Exercise>) -> Result<()
     Ok(())
 }
 
+enum RunMode {
+    Interactive,
+    NonInteractive,
+}
+
 pub fn test(exercise: &Exercise) -> Result<(), ()> {
-    compile_and_test(exercise, true)?;
+    compile_and_test(exercise, RunMode::NonInteractive)?;
     Ok(())
 }
 
@@ -24,69 +30,64 @@ fn compile_only(exercise: &Exercise) -> Result<bool, ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Compiling {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
-    let compile_output = exercise.compile();
+    let compilation_result = exercise.compile();
     progress_bar.finish_and_clear();
-    if compile_output.status.success() {
-        let formatstr = format!("{} Successfully compiled {}!", Emoji("✅", "✓"), exercise);
-        println!("{}", style(formatstr).green());
-        exercise.clean();
-        Ok(prompt_for_completion(&exercise))
-    } else {
-        let formatstr = format!(
-            "{} Compilation of {} failed! Compiler error message:\n",
-            Emoji("⚠️ ", "!"),
-            exercise
-        );
-        println!("{}", style(formatstr).red());
-        println!("{}", String::from_utf8_lossy(&compile_output.stderr));
-        exercise.clean();
-        Err(())
+
+    match compilation_result {
+        Ok(_) => {
+            success!("Successfully compiled {}!", exercise);
+            Ok(prompt_for_completion(&exercise))
+        }
+        Err(output) => {
+            warn!(
+                "Compilation of {} failed! Compiler error message:\n",
+                exercise
+            );
+            println!("{}", output.stderr);
+            Err(())
+        }
     }
 }
 
-fn compile_and_test_interactively(exercise: &Exercise) -> Result<bool, ()> {
-    compile_and_test(exercise, false)
-}
-
-fn compile_and_test(exercise: &Exercise, skip_prompt: bool) -> Result<bool, ()> {
+fn compile_and_test(exercise: &Exercise, run_mode: RunMode) -> Result<bool, ()> {
     let progress_bar = ProgressBar::new_spinner();
     progress_bar.set_message(format!("Testing {}...", exercise).as_str());
     progress_bar.enable_steady_tick(100);
 
-    let compile_output = exercise.compile();
-    if compile_output.status.success() {
-        progress_bar.set_message(format!("Running {}...", exercise).as_str());
+    let compilation_result = exercise.compile();
 
-        let runcmd = exercise.run();
-        progress_bar.finish_and_clear();
-
-        if runcmd.status.success() {
-            let formatstr = format!("{} Successfully tested {}!", Emoji("✅", "✓"), exercise);
-            println!("{}", style(formatstr).green());
-            exercise.clean();
-            Ok(skip_prompt || prompt_for_completion(exercise))
-        } else {
-            let formatstr = format!(
-                "{} Testing of {} failed! Please try again. Here's the output:",
-                Emoji("⚠️ ", "!"),
+    let compilation = match compilation_result {
+        Ok(compilation) => compilation,
+        Err(output) => {
+            progress_bar.finish_and_clear();
+            warn!(
+                "Compiling of {} failed! Please try again. Here's the output:",
                 exercise
             );
-            println!("{}", style(formatstr).red());
-            println!("{}", String::from_utf8_lossy(&runcmd.stdout));
-            exercise.clean();
+            println!("{}", output.stderr);
+            return Err(());
+        }
+    };
+
+    let result = compilation.run();
+    progress_bar.finish_and_clear();
+
+    match result {
+        Ok(_) => {
+            if let RunMode::Interactive = run_mode {
+                Ok(prompt_for_completion(&exercise))
+            } else {
+                Ok(true)
+            }
+        }
+        Err(output) => {
+            warn!(
+                "Testing of {} failed! Please try again. Here's the output:",
+                exercise
+            );
+            println!("{}", output.stdout);
             Err(())
         }
-    } else {
-        progress_bar.finish_and_clear();
-        let formatstr = format!(
-            "{} Compiling of {} failed! Please try again. Here's the output:",
-            Emoji("⚠️ ", "!"),
-            exercise
-        );
-        println!("{}", style(formatstr).red());
-        println!("{}", String::from_utf8_lossy(&compile_output.stderr));
-        exercise.clean();
-        Err(())
     }
 }
 
@@ -99,6 +100,7 @@ fn prompt_for_completion(exercise: &Exercise) -> bool {
     let success_msg = match exercise.mode {
         Mode::Compile => "The code is compiling!",
         Mode::Test => "The code is compiling, and the tests pass!",
+        Mode::Clippy => "The code is compiling, and 📎 Clippy 📎 is happy!",
     };
 
     println!("");