Run typespec-ts unit tests in the repo-wide vitest run

.chronus/changes/typespec-ts-unit-tests-repo-wide-2026-06-30-16-50-00.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@azure-tools/typespec-ts"
+---
+
+Include the fast `test-next` typespec-ts unit suite in the repo-wide vitest run as a cross-package smoke net, while keeping the heavier `unit-modular` suite and the Spector end-to-end integration project out of it. Those still run in the dedicated typespec-ts CI job, which now also triggers on the TypeSpec libraries typespec-ts emits from (`typespec-client-generator-core` and `typespec-azure-resource-manager`) so cross-package emit regressions are still caught. Scenario paths in the modular-unit suite now resolve against the package root so they no longer depend on the current working directory.

.github/workflows/ci-typescript.yml

@@ -7,6 +7,8 @@ on:
       - release/*
     paths:
       - "packages/typespec-ts/**"
+      - "packages/typespec-client-generator-core/**"
+      - "packages/typespec-azure-resource-manager/**"
       - ".github/workflows/ci-typescript.yml"
   merge_group:
 

packages/typespec-ts/test/modular-unit/scenario-runner.ts

@@ -3,6 +3,7 @@ import { afterAll, assert, describe, it } from "vitest";
 import { readdirSync, readFileSync, statSync, writeFileSync } from "fs";
 import path from "path";
 import { format } from "prettier";
+import { fileURLToPath } from "url";
 import { parse as loadYaml } from "yaml";
 import { prettierTypeScriptOptions } from "../../src/lib.js";
 import {
@@ -16,7 +17,15 @@ import {
 } from "../util/emit-util.js";
 import { assertEqualContent, clearCompileCache, ExampleJson } from "../util/test-util.js";
 
-export const SCENARIOS_LOCATION = "./test/modular-unit/scenarios";
+// Anchor scenario paths to the package root (derived from this module's URL)
+// rather than process.cwd(). This keeps the modular-unit suite working both when
+// run from this package (cwd = packages/typespec-ts) and when it is picked up by
+// the repo-wide vitest run (cwd = repo root). This file lives at
+// `<package>/test/modular-unit/scenario-runner.ts`, so the package root is two
+// directories up.
+export const PACKAGE_ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
+
+export const SCENARIOS_LOCATION = path.resolve(PACKAGE_ROOT, "test/modular-unit/scenarios");
 
 const SCENARIOS_UPDATE = process.env["SCENARIOS_UPDATE"] === "true";
 
@@ -220,8 +229,11 @@ const OUTPUT_CODE_BLOCK_TYPES: Record<string, EmitterFunction> = {
  * themselves leaf directories with their own generated test files.
  */
 export function describeScenarioDir(location: string): void {
-  for (const child of readdirSync(location)) {
-    const fullPath = path.join(location, child);
+  // `location` is package-root-relative (as emitted by gen:scenario-suites);
+  // resolve it against the package root so it is independent of process.cwd().
+  const resolved = path.resolve(PACKAGE_ROOT, location);
+  for (const child of readdirSync(resolved)) {
+    const fullPath = path.join(resolved, child);
     if (statSync(fullPath).isFile() && child.endsWith(".md")) {
       describeScenarioFile(fullPath);
     }

packages/typespec-ts/test/modular-unit/scenario-suites.guard.test.ts

@@ -1,9 +1,9 @@
 import { readdirSync } from "fs";
 import path from "path";
 import { assert, it } from "vitest";
-import { getLeafScenarioDirs } from "./scenario-runner.js";
+import { getLeafScenarioDirs, PACKAGE_ROOT } from "./scenario-runner.js";
 
-const SUITES_DIR = path.join("test", "modular-unit", "scenario-suites");
+const SUITES_DIR = path.resolve(PACKAGE_ROOT, "test", "modular-unit", "scenario-suites");
 
 function suiteFileName(relDir: string): string {
   return relDir.split(/[\\/]/).join("__") + ".test.ts";

packages/typespec-ts/vitest.config.ts

@@ -1,25 +1,55 @@
 import { defineConfig } from "vitest/config";
 
+// The repo-wide run (root `vitest.config.ts` / `vitest.config.fast.ts`) picks up
+// this file as a single project and — in Vitest 4 — ignores the nested `projects`,
+// using only these top-level `test` options. We deliberately include ONLY the fast
+// `test-next` suite there: it is a quick cross-package smoke net (~14s). The heavy
+// `unit-modular` suite (~150s of TypeSpec compiles) is intentionally excluded from
+// the repo-wide run to keep it fast; it still runs in full via `pnpm unit-test`
+// locally and in the dedicated `ci-typescript.yml` job — which also triggers on
+// the TypeSpec libraries typespec-ts emits from (`typespec-client-generator-core`
+// and `typespec-azure-resource-manager`), so cross-package emit regressions are
+// still caught. The Spector end-to-end `integration-azure-modular`
+// project needs generated clients and a running test server, so it too is excluded
+// here and runs via its own script / the dedicated e2e CI job.
+const repoWideInclude = ["test-next/**/*.test.ts"];
+
+// The `test-next` suite includes ts-morph integration tests that invoke the
+// TypeScript type checker (e.g. `binder.test.ts`). These are sub-second when run
+// on their own, but in the repo-wide run every package's tests execute
+// concurrently, and under that CPU/memory pressure they can exceed Vitest's 5s
+// default. Double the default to give some headroom without masking a genuine
+// hang. Applied both at the top level (used by the single-project repo-wide run)
+// and on the `test-next` project (used by `pnpm test-next` / `--project
+// test-next`) so the timeout holds either way.
+const testNextTimeout = 10_000;
+
+// Settings the `unit-modular` suites need (heavy TypeSpec compiles): no per-test
+// timeout and a raised heap. In Vitest 4 `poolOptions` was removed — its
+// sub-options (here `execArgv`) are now top-level `test.*` fields, set per-project.
+const unitModularPool = {
+  testTimeout: 0,
+  pool: "forks" as const,
+  execArgv: ["--max-old-space-size=1024"],
+};
+
 export default defineConfig({
   test: {
+    include: repoWideInclude,
+    testTimeout: testNextTimeout,
     projects: [
       {
         test: {
           name: "test-next",
           include: ["test-next/**/*.test.ts"],
+          testTimeout: testNextTimeout,
         },
       },
       {
         test: {
           name: "unit-modular",
           include: ["test/modular-unit/**/*.test.ts"],
-          testTimeout: 0,
-          pool: "forks",
-          poolOptions: {
-            forks: {
-              execArgv: ["--max-old-space-size=1024"],
-            },
-          },
+          ...unitModularPool,
         },
       },
       {

vitest.config.fast.ts

@@ -6,10 +6,7 @@ export default mergeConfig(
   defineConfig({
     test: {
       // Exclude core packages so we can only run test for this repo
-      projects: [
-        "packages/!(typespec-ts)/vitest.config.ts",
-        "packages/!(typespec-ts)/vitest.config.mts",
-      ],
+      projects: ["packages/*/vitest.config.ts", "packages/*/vitest.config.mts"],
     },
   }),
 );

vitest.config.ts

@@ -6,9 +6,9 @@ export default mergeConfig(
   defineConfig({
     test: {
       projects: [
-        "packages/!(typespec-ts)/vitest.config.ts",
+        "packages/*/vitest.config.ts",
         "core/packages/*/vitest.config.ts",
-        "packages/!(typespec-ts)/vitest.config.mts",
+        "packages/*/vitest.config.mts",
         "core/packages/*/vitest.config.mts",
       ],
     },