feat: add project boundary support to tspconfig.yaml

[Copilot]

Today tspconfig.yaml is purely build config — no project identity, no explicit entrypoint, no project-scoped settings. This implements Phase 1 of the project tspconfig design: project boundary marker and entrypoint resolution.

Usage

# Shorthand — defaults to main.tsp
project: true
emit:
  - "@typespec/openapi3"

# Explicit entrypoint
project:
  entrypoint: src/service.tsp
emit:
  - "@typespec/openapi3"

Changes

• Types (config/types.ts): Added TypeSpecProjectConfig, TypeSpecRawProjectConfig, and project field on both raw and normalized config interfaces
• Schema (config-schema.ts): project validates as true | { entrypoint?: string } via oneOf
• Config loader (config-loader.ts): resolveProjectConfig() normalizes raw project config, resolving entrypoint to an absolute path relative to config directory (default: main.tsp)
• CLI entrypoint resolution (entrypoint-resolution.ts): resolveTypeSpecEntrypointForDir checks project tspconfig before package.json tspMain and main.tsp fallback
• IDE entrypoint resolver (entrypoint-resolver.ts): At each directory in the walk-up, project tspconfig is checked first. If found, the walk stops — entrypoint is definitively resolved
• Tests: Config loading (shorthand, explicit entrypoint, nested projects, backward compat), schema validation, IDE resolver priority semantics, completion items updated

Backward compatibility

Existing tspconfig.yaml files without project continue to work identically. The project check is additive — only configs with project participate in the new resolution path.

Note: tsp init does not automatically add project: true to scaffolded configs, since the published compiler version would reject the unknown field. Users can manually opt-in by adding project: true to their tspconfig.yaml.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@typespec/compiler@10242

commit: aaca4b1

[timotheeguerin]

@copilot e2e test are failing, make sure the pnpm and test also pass

[Copilot]

@copilot e2e test are failing, make sure the pnpm and test also pass

Fixed in 7dac40b. The e2e validate rest template test was failing because the scaffold was adding project: true to generated tspconfig.yaml, but the e2e test uses the published compiler version (via npx tsp compile .) which doesn't know about the project field and rejects it with additionalProperties: false. Removed the automatic scaffold addition — users can manually add project: true once the feature is released. All e2e tests (32/32) and unit tests (3830) now pass.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/typespec/typespec/website/node_modules/.bin/../astro/bin/astro.mjs build sh -c tput-dir ../../w--llmstxt sh ules/.bin/node import @typespecnode systemd-run nfig/composer/vegenerate-scenarios-summary sh pec/�� rs && pnpm build:src sh /node_modules/.bin/sh --no-emit bash .2/node_modules/doc sh (dns block)
• update.code.visualstudio.com
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/typespec/typespec/packages/typespec-vscode/node_modules/.bin/../@vscode/test-web/out/server/index.js --quality stable --extensionDevelopmentPath=. --headless --extensionTestsPath=dist/test/web/suite.js ./test/web/data / --report-unusenode node /.bin/node pnpm olde�� on k/typespec/types@typespec/library-linter piler/node_modul--no-emit rts.ts node pnpm/dist/node-gformat pnpm (dns block)
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/typespec/typespec/packages/typespec-vscode/node_modules/.bin/../vitest/vitest.mjs run --root test/extension on k/typespec/typespec/temp/artifacts /.bin/node ite pec/node_modules-c /.bin/node pnpm pile�� --no-emit on /.bin/npm tsc && npm run bnode pnpm yp-bin/pnpm pnpm (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)