/AGENTS.md

This repository contains an MCP server and CLI for Chrome DevTools.

Instructions

• Use only scripts from package.json to run commands.
• Use npm run build to run tsc and test build.
• Use npm run test to build and run tests, run all tests to verify correctness.
• Use npm run test path-to-test.ts to build and run a single test file, for example, npm run test tests/McpContext.test.ts.
• Use npm run format to fix formatting and get linting errors.

Rules for TypeScript

• Do not use any type.
• Do not use as keyword for type casting.
• Do not use ! operator for type assertion.
• Do not use // @ts-ignore comments.
• Do not use // @ts-nocheck comments.
• Do not use // @ts-expect-error comments.
• Prefer for..of instead of forEach.

Testing Layering

When writing tests, follow this layered approach:

1. Tool Tests (tests/tools/*.test.ts): Should test that tools correctly configure the McpResponse based on their inputs.
2. Data Fetching Tests (tests/McpResponse.test.ts): Should test that data is correctly fetched from the browser based on the McpResponse configuration. These tests should use snapshots. Data fetching should happen in McpResponse ONLY if it is used by more than one tool.
3. Formatter Tests (tests/formatters/*.test.ts): Should test that mock data is formatted and output correctly by the formatters. These tests should use snapshots.