🔬 diag: isolate effect.events under CodSpeed at depths 2/10/50/100

Author: Taras Mankovski

.github/workflows/codspeed-diag.yaml

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+name: CodSpeed Diag
+
+on:
+  push:
+    branches: [codspeed-diag]
+
+permissions:
+  contents: read
+  id-token: write
+
+jobs:
+  diag:
+    runs-on: ubuntu-latest
+    timeout-minutes: 12
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+
+      - name: setup deno
+        uses: denoland/setup-deno@v2
+        with:
+          deno-version: v2.x
+
+      - name: setup node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+
+      - name: build effection npm package
+        run: |
+          deno task build:npm 0.0.0-bench
+          cd build/npm
+          npm pack
+          mv *.tgz ../../effection.tgz
+
+      - name: install bench-node deps
+        working-directory: bench-node
+        run: |
+          npm install ../effection.tgz --legacy-peer-deps
+          npm install --legacy-peer-deps
+
+      - name: run effect.events diagnostic under CodSpeed
+        uses: CodSpeedHQ/action@v4
+        with:
+          mode: simulation
+          run: node --experimental-strip-types bench-node/diag.bench.ts

bench-node/diag.bench.ts

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+/**
+ * DIAGNOSTIC (throwaway): isolate effect.events under CodSpeed instrumentation
+ * at several depths to tell hang-vs-slow apart.
+ *
+ * Watch the runner's "Measured … effect.events@N" markers:
+ *  - all complete quickly  -> size/slowness (a smaller depth rescues it)
+ *  - @2 itself never prints -> fundamental hang under Valgrind (drop it)
+ *
+ * Run: node --experimental-strip-types bench-node/diag.bench.ts
+ */
+
+import { Bench } from "tinybench";
+import { withCodSpeed } from "@codspeed/tinybench-plugin";
+import { run } from "effection";
+import { effectEvents } from "./scenarios/effect.events.ts";
+
+const bench = withCodSpeed(new Bench());
+
+for (const depth of [2, 10, 50, 100]) {
+  bench.add(`effect.events@${depth}`, async () => {
+    await run(() => effectEvents.run(depth));
+  });
+}
+
+await bench.run();
+console.table(bench.table());