Sim-PR-Lifier

A cross-browser browser extension that adds focusable change categories to a GitHub pull request's Files changed page. Selections are stored with browser sync and continue to work as GitHub loads more files or navigates without a full page refresh.

The pull-request header replaces GitHub's combined line total with a breakdown for Core, Comments, Tests, Config, Migrations, and test Artifacts. JSON, JSONC, YAML, and YML files count as Config; SQL counts as Migrations. Snapshots, golden files, fixtures, recordings, cassettes, and testdata paths count as Artifacts. A category excluded by the active filters is muted and struck through. An Other category appears only if GitHub has not yet loaded enough file metadata to classify every changed line.

Click one or more categories to compose a focused view, such as Core + Config. Click selected categories again to remove them; clearing the final selection returns to the full diff. GitHub's gear menu is left unchanged.

Whitespace-only changes are hidden by default. When a pull-request diff opens, the extension preserves the existing URL options and enables GitHub's native w=1 diff mode if it is not already active.

The extension supports both GitHub's current /changes interface and the legacy /files interface.

Example:

Supported browsers

Chrome, Firefox, and Edge (Manifest V3).

Install

1. Open chrome://extensions in Chrome/Edge, or about:debugging#/runtime/this-firefox in Firefox.
2. Enable Developer mode.
3. Click Load unpacked and select this directory.
4. Open a pull request and choose Files changed.

Reload an already-open GitHub tab once after installing the extension.

Test-file detection

The extension recognizes common conventions including tests/, test/, __tests__/, spec/, e2e/, Cypress, *_test.go, test_*.py, *.test.tsx, *.spec.js, and popular test-runner config files. Test fixtures, snapshots, golden files, recordings, and cassettes are classified separately as Artifacts.

Development

The extension has no runtime dependencies or build step. To run its tests:

npm install
npm test

To package distributable zips for Chrome and Firefox:

npm run package

The Firefox build adds browser_specific_settings to its manifest copy.

Architecture

• src/classify.js — pure file-category classification.
• src/storage.js — cross-browser promise-based settings sync and extension-context guard.
• src/dom.js — DOM selectors, path reading, and line-stat parsing.
• src/ui.js — breakdown rendering and filter class application.
• src/content.js — orchestrator: lifecycle, scheduling, and routing.