## Summary
- make `check-merge-conflict` detect conflict blocks contextually
instead of flagging any bare `=======`
- add support for diff3 ancestor markers (`|||||||`)
Closes#1924Closes#1523
## Description
Following the information provided in
[880](https://github.com/j178/prek/issues/880). This is an
implementation of the `pretty-format-json` hook.
The
[pretty-format-json](https://grep.app/search?f.path.pattern=.pre-commit-config.yaml&q=pretty-format-json)
has 1k grep.app hits. It's the final unimplemented hook used by
`airflow` as mentioned in [this
comment](https://github.com/j178/prek/issues/880#issuecomment-3405716137).
----
## Notes
- **Preserve JSON Order**
- Added the `preserve_order` feature to `serde_json`. This prevents
`serde` from automatically ordering JSON data, which is important for
comparisons with older implementations.
- This change does not appear to affect other tests/features.
- By default, `serde` uses a `BTreeMap` for `Object`. Enabling
`preserve_order` switches it to `IndexMap`.
- This keeps the sorting logic within the `sort-keys` argument.
- **Git-Style Diff with `similar`**
- Added the `similar` library to perform git-style diff checks.
- Binary size increase is minimal.
- Useful as a general utility and could be leveraged in other parts of
the project, maybe needed to be relocated?
- Added color highlighting to the diffs, improving readability compared
to original `pre-commit`.
```bash
cargo clean
cargo build --release
```
- Master branch: **8.49 MB**
- Feature branch: **8.55 MB**
- **+66,176 bytes** (**+0.74%**) increase from master to feature branch
_Q: why is my size so much smaller than both sizes mentioned
[here](https://github.com/j178/prek/pull/884#issuecomment-3406885242)?_
-----
### Performance
Ran these commands on the `airflow` repository:
```bash
# old
pre-commit run pretty-format-json --all-files --verbose
Format JSON files........................................................Passed
- hook id: pretty-format-json
- duration: 0.03s
# Old prek implementation (python)
prek run pretty-format-json --all-files --verbose
Format JSON files........................................................Passed
- hook id: pretty-format-json
- duration: 0.03s
# New implementation (rust)
prek run pretty-format-json --all-files --verbose
Format JSON files........................................................Passed
- hook id: pretty-format-json
- duration: 0.00s
```
## Output
Old pre-commit:
<img width="601" height="376" alt="image"
src="https://github.com/user-attachments/assets/f0553015-24cf-4d23-98e8-2759f912c9b3"
/>
New:
<img width="707" height="430" alt="image"
src="https://github.com/user-attachments/assets/fa7ce303-caa9-4139-9e77-6e58db5f0725"
/>
Where both would autofix to the same:
<img width="349" height="304" alt="image"
src="https://github.com/user-attachments/assets/67baf526-787b-4aa6-a0fe-7859a2a5fb8b"
/>
---------
Co-authored-by: Felix Blom <70511386+Felix-Blom@users.noreply.github.com>
Co-authored-by: Jo <10510431+j178@users.noreply.github.com>
## Summary
Add a native Rust fast path for the `check-vcs-permalinks` hook from
`pre-commit/pre-commit-hooks`.
## Why this matters
Without a fast path, prek must clone the `pre-commit/pre-commit-hooks`
repo, install Python, and run the hook script. The native implementation
avoids that overhead for a simple regex-based check.
## Changes
- New file:
`crates/prek/src/hooks/pre_commit_hooks/check_vcs_permalinks.rs`
- Port of the [upstream Python
implementation](https://github.com/pre-commit/pre-commit-hooks/blob/main/pre_commit_hooks/check_vcs_permalinks.py)
- Detects GitHub blob URLs that use a branch name (e.g. `main`,
`master`) instead of a commit hash, combined with a `#L` line number
anchor
- Scans files concurrently using the existing
`run_concurrent_file_checks` helper
- Reports file path, line number, and offending line content
- Includes unit tests for permalinks, branch links, and edge cases
- Updated `crates/prek/src/hooks/pre_commit_hooks/mod.rs`: added
`CheckVcsPermalinks` variant
## Testing
- `cargo check -p prek` passes
- Unit tests verify both positive (branch link) and negative (commit
hash permalink) cases
Fixes#1833
This contribution was developed with AI assistance (Claude Code).
---------
Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Jo <10510431+j178@users.noreply.github.com>
## Summary
Add a native Rust fast path for the `check-illegal-windows-names` hook
from `pre-commit/pre-commit-hooks`.
## Why this matters
Without a fast path, prek must clone the `pre-commit/pre-commit-hooks`
repo and parse `.pre-commit-hooks.yaml` just to run a regex-based
filename check. The native implementation skips that overhead entirely.
## Changes
- New file:
`crates/prek/src/hooks/pre_commit_hooks/check_illegal_windows_names.rs`
- Uses the same regex from upstream's
[`.pre-commit-hooks.yaml`](https://github.com/pre-commit/pre-commit-hooks/blob/f1dff44d3a9ae852957f34def96390f28719c232/.pre-commit-hooks.yaml#L49)
- Detects reserved names (CON, PRN, AUX, NUL, COM1-9, LPT1-9), illegal
characters (<>:"|?*), control characters, and trailing dots/spaces
- Includes unit tests for legal filenames, reserved names, illegal
characters, and trailing dots/spaces
- Updated `crates/prek/src/hooks/pre_commit_hooks/mod.rs`: added
`CheckIllegalWindowsNames` variant to enum and wired up the `run`
dispatch
## Testing
- `cargo check -p prek` passes
- Unit tests cover legal names, reserved names, illegal characters, and
trailing dots/spaces
Fixes#1835
This contribution was developed with AI assistance (Claude Code).
---------
Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Jo <10510431+j178@users.noreply.github.com>
Jo
RicardoVercetti
Felix Blom
Matt Van Horn
Shaan Majid
Matthias Schoettle
Louis Maddox
ChiLin Chiu
Les Freire
Kushagra Udai