perf(cli): skip native-binary build tests by default

The build-exe and build-exe-cross suites invoke `bun build` in beforeAll
hooks and pegged CPU for ~6 min on every test run (one cached-on-miss
build plus three unconditional cross-target builds). Move them to a
dedicated vitest project, skip them unless CI=1 or FUSION_TEST_BUILD_EXE=1
is set, and add cache guards so CI re-runs skip rebuilds when the target
binary already exists. With build-exe out of the default cli run, the
main config can enable fileParallelism.

Run on demand via `pnpm --filter @runfusion/fusion test:build-exe`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/cli/package.json

@@ -42,7 +42,8 @@
     "build:exe": "bun run build.ts",
     "build:exe:all": "bun run build.ts --all",
     "typecheck": "tsc --noEmit",
-    "test": "vitest run --silent=passed-only --reporter=dot"
+    "test": "vitest run --silent=passed-only --reporter=dot",
+    "test:build-exe": "FUSION_TEST_BUILD_EXE=1 vitest run --config vitest.build-exe.config.ts --silent=passed-only --reporter=dot"
   },
   "dependencies": {
     "@fusion/pi-claude-cli": "workspace:*",

packages/cli/src/__tests__/build-exe-cross.test.ts

@@ -38,9 +38,15 @@ function nativeTarget(): string | null {
   return `bun-${platform}-${arch}`;
 }
 
-describe("build-exe-cross: single target", () => {
+// Cross-compiling native binaries pegs CPU for ~60s per target. Skip by
+// default locally; opt in with FUSION_TEST_BUILD_EXE=1 or run on CI.
+const SHOULD_RUN_BUILD_EXE =
+  Boolean(process.env.FUSION_TEST_BUILD_EXE) || Boolean(process.env.CI);
+
+describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe-cross: single target", () => {
   beforeAll(() => {
-    // Build for linux-x64 specifically
+    const bin = join(distDir, "fn-linux-x64");
+    if (existsSync(bin)) return;
     execSync("bun run build.ts --target bun-linux-x64", {
       cwd: cliRoot,
       stdio: "pipe",
@@ -59,8 +65,10 @@ describe("build-exe-cross: single target", () => {
   });
 });
 
-describe("build-exe-cross: windows target has .exe extension", () => {
+describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe-cross: windows target has .exe extension", () => {
   beforeAll(() => {
+    const bin = join(distDir, "fn-windows-x64.exe");
+    if (existsSync(bin)) return;
     execSync("bun run build.ts --target bun-windows-x64", {
       cwd: cliRoot,
       stdio: "pipe",
@@ -75,8 +83,12 @@ describe("build-exe-cross: windows target has .exe extension", () => {
   });
 });
 
-describe("build-exe-cross: --all builds all platforms", () => {
+describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe-cross: --all builds all platforms", () => {
   beforeAll(() => {
+    const allBuilt = SUPPORTED_TARGETS.every((target) =>
+      existsSync(join(distDir, expectedBinaryName(target))),
+    );
+    if (allBuilt) return;
     execSync("bun run build.ts --all", {
       cwd: cliRoot,
       stdio: "pipe",
@@ -147,8 +159,11 @@ describe("build-exe-cross: --all builds all platforms", () => {
   }, 60_000);
 });
 
-describe("build-exe-cross: default (no args) backward compatibility", () => {
+describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe-cross: default (no args) backward compatibility", () => {
   beforeAll(() => {
+    const defaultName = process.platform === "win32" ? "fn.exe" : "fn";
+    const bin = join(distDir, defaultName);
+    if (existsSync(bin)) return;
     execSync("bun run build.ts", {
       cwd: cliRoot,
       stdio: "pipe",

packages/cli/src/__tests__/build-exe.test.ts

@@ -61,7 +61,12 @@ async function stopChildProcess(child: ChildProcess | null): Promise<void> {
   });
 }
 
-describe("build-exe", () => {
+// Native-binary build tests are expensive (~2 min of pegged CPU). Skip by
+// default locally; opt in with FUSION_TEST_BUILD_EXE=1 or run on CI.
+const SHOULD_RUN_BUILD_EXE =
+  Boolean(process.env.FUSION_TEST_BUILD_EXE) || Boolean(process.env.CI);
+
+describe.skipIf(!SHOULD_RUN_BUILD_EXE)("build-exe", () => {
   beforeAll(() => {
     // Build the executable (skip if already built to speed up re-runs)
     if (!existsSync(outBinary)) {

packages/cli/vitest.build-exe.config.ts

@@ -0,0 +1,34 @@
+import { defineConfig } from "vitest/config";
+import { resolve } from "node:path";
+
+// Separate project for the native-binary build tests. These invoke `bun build`
+// and can peg CPU for minutes. They are skipped by default (see skipIf guards
+// inside the test files) and run via `pnpm test:build-exe` or when CI=1 /
+// FUSION_TEST_BUILD_EXE=1 is set.
+//
+// fileParallelism is false here because both suites write to packages/cli/dist/
+// and would race each other in parallel workers.
+
+export default defineConfig({
+  resolve: {
+    alias: [
+      { find: /^@fusion\/core\/gh-cli$/, replacement: resolve(__dirname, "../core/src/gh-cli.ts") },
+      { find: /^@fusion\/core$/, replacement: resolve(__dirname, "../core/src/index.ts") },
+      { find: /^@fusion\/dashboard\/planning$/, replacement: resolve(__dirname, "../dashboard/src/planning.ts") },
+      { find: /^@fusion\/dashboard$/, replacement: resolve(__dirname, "../dashboard/src/index.ts") },
+      { find: /^@fusion\/engine$/, replacement: resolve(__dirname, "../engine/src/index.ts") },
+      { find: /^@fusion\/test-utils$/, replacement: resolve(__dirname, "../core/src/__test-utils__/workspace.ts") },
+    ],
+  },
+  test: {
+    include: ["src/__tests__/build-exe*.test.ts"],
+    setupFiles: [
+      "./src/__tests__/setup-test-isolation.ts",
+      resolve(__dirname, "../core/src/__test-utils__/vitest-setup.ts"),
+    ],
+    globalSetup: [resolve(__dirname, "../core/src/__test-utils__/vitest-teardown.ts")],
+    fileParallelism: false,
+    testTimeout: 360_000,
+    hookTimeout: 360_000,
+  },
+});

packages/cli/vitest.config.ts

@@ -23,6 +23,10 @@ export default defineConfig({
   },
   test: {
     include: ["src/**/*.test.ts"],
+    // build-exe + build-exe-cross live in their own vitest project
+    // (see vitest.build-exe.config.ts) so the rest of the CLI suite can
+    // run with file parallelism enabled.
+    exclude: ["**/node_modules/**", "**/dist/**", "src/__tests__/build-exe*.test.ts"],
     setupFiles: [
       "./src/__tests__/setup-test-isolation.ts",
       resolve(__dirname, "../core/src/__test-utils__/vitest-setup.ts"),
@@ -30,9 +34,7 @@ export default defineConfig({
     globalSetup: [resolve(__dirname, "../core/src/__test-utils__/vitest-teardown.ts")],
     maxWorkers,
     poolOptions: { threads: { minThreads: 1, maxThreads: maxWorkers }, forks: { minForks: 1, maxForks: maxWorkers } },
-    // build-exe and build-exe-cross suites both operate on packages/cli/dist/
-    // and can race when run in parallel workers.
-    fileParallelism: false,
+    fileParallelism: true,
     coverage: {
       enabled: false,
       reporter: ["text", "html", "json"],