devtools-frontend

Use when starting a new task, creating a branch, switching branches, managing branches, creating and uploading CLs, handling stacked changes, or checking release and roll status in the DevTools Gerrit-based workflow. ALWAYS use this instead of running standard git checkout/switch commands for branch creation.

Guidelines for building UI widgets using the MVP architecture in DevTools. Covers Widget lifecycle, lit-html views, and state management.

Promotes legacy views to modern UI.Widget classes, hooks up performUpdate() rendering, and exports default views.

Scaffolds unit tests and screenshot tests to establish visual and functional rendering baselines for views before refactoring.

High-level orchestrator for managing multi-pass migration of Chrome DevTools legacy components to the modern UI engineering vision (UI.Widget & Lit-html).

Consolidates manual DOM creation, updates, and constructors into private helper methods and structured state interfaces.

Migrates legacy imperative DOM construction to local declarative Lit-html templates rendered inside existing containers.

Reproduce and investigate flakiness in a test.

Use when migrating Chromium layout tests to DevTools unit tests or API tests.

Workflow for merging a DevTools submodule into its parent module. Covers BUILD.gn consolidation and updating devtools_grd_files.gni.

Migrating unit tests to foundation unit tests using TestUniverse and devtools_foundation_module. Use when moving tests away from DOM-heavy helpers like describeWithEnvironment or describeWithMockConnection.

Use this skill when unskipping a test that was previously skipped.

Expose a temporary evaluation hook in DevTools and run a Puppeteer script to validate CSS code completion trigger rates.

MANDATORY: Activate this skill ANY TIME you need to build the project, run tests, or verify code health in DevTools. You MUST use this skill before executing commands like npm test, npm run build, autoninja, or linters, as it contains critical, repository-specific instructions on how to correctly format these commands, filter test runs, and interpret failures.

Refactor user-facing UIStrings and localization comments in a DevTools module folder according to UX writing guidelines (child task of b/40799900). Use when simplifying wording, checking sentence case, or improving L10n comments in UIStrings for a specific folder or issue. Don’t use for general code changes or non-UIStrings files.

Guidelines for escaping strings and handling user-controlled data in DevTools to prevent layout bleed-through, XSS, and security issues.

Guidance on selecting the appropriate test suite (Unit, API, or E2E tests) when writing new tests in Chrome DevTools. MUST be used when writing new tests.

Guidelines for utilizing source maps and structured stack traces in DevTools. Covers DebuggerWorkspaceBinding, StackTrace, SymbolizedError, and related UI widgets.

Workflow for splitting an existing SettingRegistration into a SettingDescriptor (placed in the lowest layer where used: core/, models/, or ui/settings/) and SettingUIDescriptor (registered in a higher-level -meta.ts file, outside of core/ and models/).

Guidelines for creating, migrating, and registering models in front_end/models/. Covers BUILD.gn, devtools_grd_files.gni, and entrypoints.

Conventions for importing code in Devtools to avoid build errors. Covers cross-module imports, internal imports, and the "import * as" requirement.