Context Drift

A small CLI for spotting when new code starts to drift from your repository's naming conventions.

Context Drift scans supported source files, summarizes their naming styles, and highlights the files that changed relative to git or an explicit file list.

What it checks **/*.ts **/*.tsx **/*.js **/*.jsx What it ignores node_modules .git .next dist build coverage

Quick Start

npm install
npm run build
npx context-drift check --base main

If you already know which files changed, you can pass them directly:

npx context-drift check --changed src/cli.ts,src/scanner.ts

Output

The default report is intentionally simple:

Context Drift

Files scanned: 142
Changed files: 3
Format: markdown

Naming conventions:
- PascalCase: 12%
- kebab-case: 18%
- camelCase: 41%
- snake_case: 9%
- lower-case: 20%
- upper-case: 0%

CLI

The project exposes one command:

context-drift check

Options:

• --base <branch>: diff against base...HEAD and treat those files as changed.
• --changed <files>: comma-separated, repo-relative paths to mark as changed.
• --format <format>: accepts markdown or json and is reflected in the report header.

Examples:

npx context-drift check --base origin/main
npx context-drift check --format json
npx context-drift check --changed src/index.ts,src/cli.ts

Demo

This repository includes a small clean/drifted Next.js-style example under examples/. After building, run:

node dist/index.js check --changed "examples/nextjs-drifted/src/utils/apiClient.ts,examples/nextjs-drifted/src/components/user_profile_card.tsx,examples/nextjs-drifted/src/utils/dateFormat.ts"

The drifted example includes an API helper in an unusual folder, a snake_case component file, and a date helper that resembles existing utilities.

GitHub Action

This repository runs Context Drift automatically on pull requests with .github/workflows/context-drift.yml. The workflow checks out the full git history, runs the local action against the pull request diff, and posts or updates a single bot comment when drift findings exist.

Add this workflow to run Context Drift on pull requests:

name: Context Drift

on:
  pull_request:
    types: [opened, synchronize, reopened, ready_for_review]

jobs:
  context-drift:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: read
      issues: write

    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: actions/setup-node@v4
        with:
          node-version: 20

      - uses: 7shep/context-drift@v0.1
        with:
          base-ref: origin/${{ github.base_ref }}
          min-confidence: "0.75"
          format: markdown
          github-token: ${{ secrets.GITHUB_TOKEN }}

When github-token is provided on a pull request event, the action posts one Context Drift comment and updates that same comment on later runs.

Development

npm run dev
npm test
npm run typecheck

Contributing

Read CONTRIBUTING.md before opening a pull request.

Typical contribution flow:

1. Create a branch for one issue.
2. Make the smallest change that solves that issue.
3. Run the relevant checks:
   • npm run build
   • npm test
   • npm run typecheck
4. Open a focused PR with a clear summary and validation notes.

How It Works

1. Resolve changed files from --changed or git diff --name-only <base>...HEAD.
2. Scan the repository for supported source files.
3. Normalize paths and mark files that are part of the changed set.
4. Classify file names into naming styles such as PascalCase, camelCase, kebab-case, and snake_case.
5. Print a compact summary that is easy to read in a terminal or CI log.

Project Layout

• src/index.ts bootstraps the CLI.
• src/cli.ts defines commands and output.
• src/scanner.ts finds supported files and normalizes paths.
• src/git.ts reads git diff output.
• src/naming.ts classifies file naming styles.
• tests/ contains the Vitest coverage for the scanner, git helpers, and naming logic.

Requirements

• Node.js 20 or newer
• Git for --base comparisons