Testing Guide

Use the Node/pnpm versions in package.json. Tests use Mocha and an extension host via @vscode/test-cli; dependencies must be installed before running them.

Commands

Run from the repository root:

pnpm check-types
pnpm lint
pnpm test

pnpm test compiles tests, type-checks/builds the extension, runs lint, and launches the VS Code test host. Use type-check/lint during editing, then the full suite for behavior changes. For tests-only iteration, pnpm build-tests refreshes compiled tests and pnpm watch-tests watches them.

The checked-in .vscode-test.mjs selects out/test/**/*.test.js. If the host cannot start (for example, a missing cached executable), fix the test-host installation or select a verified local installation with a temporary test-runner configuration. A launch failure is not a passing test run; do not commit machine-specific paths.

Suite Map

Area under src/test	Coverage
extension.test.ts	Activation and registered commands
schemas	Request schema validation
utils	Configuration, models, images, and shared helpers
server conversion suites	Anthropic, Chat, Responses, and Gemini message/tool conversion
server/toolHistory*.test.ts	Shared normalization and official SDK stream compatibility
server/*WebSearch.test.ts	Hosted/standalone search, provider limits, and isolation
server/sseHeartbeat.test.ts and languageModelRequestLifecycle.test.ts	Heartbeats, cancellation, timeouts, and stream ordering

Use the test runner's output for current counts; parameterized suites make manually maintained totals unreliable.

Adding Tests

Follow existing suite / test conventions with Node assert. Cover the observable regression, restore mocks/listeners in cleanup hooks, and use isolated temporary files/ports. Do not make ordinary tests consume external model or Exa quota. See AGENTS.md for required coverage.

Manual Validation

Unit tests do not prove UI behavior or live provider compatibility. Record the AM revision, VS Code/client versions, model, isolated ports, expected output, and relevant AM logs for manual runs. Avoid sharing raw request/session logs without applying the logging guidance.

• Use the Codex collaboration runbook for Responses namespace/plaintext collaboration changes.
• Recheck image MIME behavior when changing the VS Code engine.
• For documentation-only edits, check links, anchors, examples, and diagrams. Build the website if its source changes; model requests and a full extension-host run are unnecessary unless behavior also changes.