Port style50.vsix formatting capability over

[rongxin-liu]

Related PR: cs50/style50.vsix#12

[Copilot]

Pull request overview

Ports formatting capabilities from the style50 VSIX into the core CLI/library, adding formatters for additional languages and a new CLI output mode for emitting formatted source.

Changes:

• Add HTML/CSS/SQL formatting support (djhtml/cssbeautifier/sqlparse).
• Add --clang-format-style support and a per-run configure() hook for style checks.
• Add CLI -o format mode plus API format_file(), and bump package version to 3.0.0 with new dependencies.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

File	Description
style50/languages.py	Adds HTML/CSS/SQL style checks and introduces clang-format style override support for C-derived checks.
style50/_api.py	Adds clang_format_style plumbing, format_file(), and invokes optional configure() hook before checks run.
style50/main.py	Adds format output mode and --clang-format-style CLI flag.
setup.py	Adds new formatter dependencies and bumps version to 3.0.0.

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[Copilot]

Pull request overview

This PR ports “formatting mode” capabilities into style50, adding a CLI/API path to emit formatted code (or rewrite files in place) and expanding formatter support beyond the existing languages to better match the VS Code extension’s needs.

Changes:

• Adds output=format + --in-place / --side-by-side CLI support, and threads --clang-format-style through the API.
• Introduces new formatters for HTML (djhtml), CSS (cssbeautifier), and SQL (sqlparse), plus tests for formatter invocation and clang-format flag preservation.
• Updates packaging/CI to install test extras and run pytest.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
style50/__main__.py	Adds format mode, --in-place, --side-by-side, --clang-format-style, and updates argument wiring.
style50/_api.py	Adds format_file() / format_files_in_place(), threads clang_format_style into checks, and guards run() in format mode.
style50/languages.py	Adds HTML/CSS/SQL formatters and clang-format style override behavior in C (preserving subclass flags).
tests/test_languages.py	Unit tests for new formatters and clang-format override behavior.
tests/test_cli.py	CLI integration tests for format mode, in-place rewriting, ignore patterns, and flag conflicts.
setup.py	Adds new formatter dependencies + test extras and bumps version to 3.0.0.
.github/workflows/main.yml	Runs pytest in CI via pip install '.[test]'.

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