checking-changes

Validates all code changes before committing by running format, lint, type, and unit test checks. Use after making backend (Python) or frontend (TypeScript) changes, before committing or finishing a work session.

44,152 stars
Complexity: easy

About this skill

The `checking-changes` skill streamlines your development workflow by automating crucial pre-commit validation steps. Designed for both backend (Python) and frontend (TypeScript) changes within the Streamlit project, this skill executes a comprehensive suite of checks including code formatting, linting, type verification, and unit tests on all uncommitted files (staged, unstaged, and untracked). It provides a clear workflow: run the `make check` command, identify and fix any reported errors, and repeat until all checks pass, ensuring high code quality and consistency before final commit or session completion.

Best use case

Ensuring code quality and consistency across a project by automatically validating changes against established standards (formatting, linting, typing, unit tests) before they are committed or a work session is finished.

Validates all code changes before committing by running format, lint, type, and unit test checks. Use after making backend (Python) or frontend (TypeScript) changes, before committing or finishing a work session.

All code changes pass format, lint, type, and unit tests, indicating that the code adheres to project quality standards and is ready for committing. The agent will confirm that 'make check' succeeded.

Practical example

Example input

Please check all my recent code changes for formatting, linting, type errors, and run unit tests. Let me know if everything passes.

Example output

Running 'make check' to validate uncommitted changes...

Formatting checks passed.
Linting checks passed.
Type checks passed.
Unit tests passed.

All checks completed successfully. Your code changes meet the project's quality standards and are ready to be committed.

When to use this skill

  • After completing a set of code changes (Python or TypeScript), before committing your work, or at the end of a development session to verify all modifications meet project standards.

When not to use this skill

  • After every minor edit or small change; this skill is intended for validating a completed set of changes, not for real-time, granular feedback on individual keystrokes. It also does not include End-to-End (E2E) tests by default.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/checking-changes/SKILL.md --create-dirs "https://raw.githubusercontent.com/streamlit/streamlit/main/.claude/skills/checking-changes/SKILL.md"

Manual Installation

  1. Download SKILL.md from GitHub
  2. Place it in .claude/skills/checking-changes/SKILL.md inside your project
  3. Restart your AI agent — it will auto-discover the skill

How checking-changes Compares

Feature / Agentchecking-changesStandard Approach
Platform SupportClaudeLimited / Varies
Context Awareness High Baseline
Installation ComplexityeasyN/A

Frequently Asked Questions

What does this skill do?

Validates all code changes before committing by running format, lint, type, and unit test checks. Use after making backend (Python) or frontend (TypeScript) changes, before committing or finishing a work session.

Which AI agents support this skill?

This skill is designed for Claude.

How difficult is it to install?

The installation complexity is rated as easy. You can find the installation instructions above.

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

Related Guides

SKILL.md Source

# Checking Changes

**Run at the end of a work session** or after completing a set of changes — not after every small edit.

```bash
make check
```

This runs formatting, linting, type checking, and unit tests on all uncommitted files (staged, unstaged, and untracked).

## Workflow

1. Run `make check`
2. If issues are found:
   - Fix the reported errors
   - Re-run `make check`
   - Repeat until all checks pass
3. Only consider work complete when `make check` succeeds

## Notes

- E2E tests are not included by default; use `E2E_CHECK=true make check` to also run changed e2e tests
- E2E snapshot mismatches can be ignored (they require manual updates)

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