Support vitest 5

.github/workflows/codspeed.yml

@@ -28,6 +28,7 @@ jobs:
             bench: |
               pnpm turbo run bench --filter=@codspeed/vitest-plugin
               pnpm --workspace-concurrency 1 -r bench-vitest
+              for ex in examples/with-vitest-*; do pnpm -C "$ex" bench-vitest || exit 1; done
           - plugin: benchmark.js
             bench: |
               pnpm turbo run bench --filter=@codspeed/benchmark.js-plugin
@@ -48,6 +49,11 @@ jobs:
           key-suffix: ${{ matrix.plugin }}
       - run: pnpm install --frozen-lockfile --prefer-offline
       - run: pnpm turbo run build
+      # Outside the root workspace; installed after the build so their copy of
+      # the plugin includes `dist/`.
+      - name: Install vitest examples
+        if: matrix.plugin == 'vitest'
+        run: for ex in examples/with-vitest-*; do pnpm -C "$ex" install --frozen-lockfile --prefer-offline; done
 
       - name: Run simulation benchmarks
         uses: CodSpeedHQ/action@main
@@ -76,8 +82,14 @@ jobs:
           node-version-file: .nvmrc
       - name: Restore turbo cache
         uses: ./.github/actions/turbo-cache
+        # The native addon prebuild links against the host's libstdc++, which
+        # Turbo does not hash; keep GitHub's arm64 runners' builds out.
+        with:
+          key-suffix: codspeed-macro
       - run: pnpm install --frozen-lockfile --prefer-offline
       - run: pnpm turbo run build
+      - name: Install vitest examples
+        run: for ex in examples/with-vitest-*; do pnpm -C "$ex" install --frozen-lockfile --prefer-offline; done
 
       - name: Run benchmarks
         # use version from `main` branch to always test the latest version, in real projects, use a tag, like `@v2`
@@ -92,6 +104,7 @@ jobs:
             pnpm turbo run bench --filter=@codspeed/benchmark.js-plugin
             pnpm --workspace-concurrency 1 -r bench-tinybench
             pnpm --workspace-concurrency 1 -r bench-vitest
+            for ex in examples/with-vitest-*; do pnpm -C "$ex" bench-vitest || exit 1; done
 
   codspeed-walltime-macos:
     runs-on: macos-latest
@@ -145,6 +158,8 @@ jobs:
 
       - name: Restore turbo cache
         uses: ./.github/actions/turbo-cache
+        with:
+          key-suffix: codspeed-macro
 
       - name: Install repo dependencies
         run: pnpm install --frozen-lockfile --prefer-offline

.gitignore

@@ -132,3 +132,5 @@ packages/app/.env
 # turbo
 .turbo/
 .rollup.cache/
+
+.codspeed

CLAUDE.md

@@ -94,4 +94,25 @@ Based on the codebase analysis, to add stats access features:
   - Build: `pnpm turbo run build --filter=<package-name>`
   - Typecheck: `pnpm turbo run typecheck --filter=<package-name>`
   - Lint: `pnpm turbo run lint --filter=<package-name>`
-  - Run a task across all packages by omitting `--filter` (e.g. `pnpm turbo run build`).
+  - Run a task across all packages by omitting `--filter` (e.g. `pnpm turbo run build`).
+
+## Testing a plugin during development
+
+A plugin behaves differently depending on whether CodSpeed is driving the run,
+so exercise all three of these when developing or reviewing a plugin change
+(build the plugin first — the benches import from `dist`):
+
+1. **Fallback (not under CodSpeed).** No env vars. The plugin must stay out of
+   the way and let the framework run its benchmarks normally (no instrumentation,
+   no hijacked output). e.g. `pnpm turbo run bench --filter=<package-name>`.
+2. **Instrumentation / simulation.** `CODSPEED_ENV=true CODSPEED_RUNNER_MODE=simulation`
+   (or `instrumentation`). The plugin hijacks the run to do a single instrumented
+   pass per benchmark and prints `Measured/Checked <uri>` instead of the normal
+   harness output.
+3. **Walltime.** `CODSPEED_ENV=true CODSPEED_RUNNER_MODE=walltime`. The plugin
+   instruments the framework's real benchmark loop and collects walltime results.
+
+Running these locally outside the CodSpeed runner is expected to log
+`instrument-hooks: failed to write environment.json` and skip actual measurement
+writes — the point is to verify the plugin's control flow and output per mode,
+not to produce real measurements.

examples/with-typescript-esm/package.json

@@ -16,6 +16,6 @@
     "tinybench": "^4.0.1",
     "tsx": "^4.23.12",
     "typescript": "^5.1.3",
-    "vitest": "^4.0.18"
+    "vitest": "^5.0.0"
   }
 }

examples/with-typescript-esm/src/fibonacci.bench.ts

@@ -1,8 +1,14 @@
-import { bench, describe } from "vitest";
-import { recursiveFibonacci } from "./fibonacci";
+import { describe, test } from "vitest";
+import { recursiveFibonacci as recursiveFibonacciExport } from "./fibonacci";
+
+// Imports are getters under Vite's module runner; read them once, outside the
+// measured loop.
+const recursiveFibonacci = recursiveFibonacciExport;
 
 describe("recursiveFibonacci", () => {
-  bench("fibo 30", () => {
-    recursiveFibonacci(30);
+  test("fibo 30", async ({ bench }) => {
+    await bench("fibo 30", () => {
+      recursiveFibonacci(30);
+    }).run();
   });
 });

examples/with-vitest-v3/package.json

@@ -6,8 +6,9 @@
     "bench-vitest": "vitest bench --run"
   },
   "devDependencies": {
-    "@codspeed/vitest-plugin": "workspace:*",
+    "@codspeed/vitest-plugin": "file:../../packages/vitest-plugin",
     "typescript": "^5.1.3",
     "vitest": "^3.2.4"
-  }
+  },
+  "packageManager": "pnpm@10.12.4"
 }