From 5b294b7fbd63221497afacf17e8ff6be7aa5dcda Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sat, 4 Apr 2026 05:20:07 +0100
Subject: [PATCH] test: keep vitest thread workers conservative

---
 src/infra/vitest-config.test.ts   | 26 ++++++++++++++++++++++----
 test/vitest-scoped-config.test.ts | 16 ++++++++++++----
 vitest.shared.config.ts           | 18 ++++++++++++++++--
 3 files changed, 50 insertions(+), 10 deletions(-)

diff --git a/src/infra/vitest-config.test.ts b/src/infra/vitest-config.test.ts
index 500f9afdd38..bbd373a210f 100644
--- a/src/infra/vitest-config.test.ts
+++ b/src/infra/vitest-config.test.ts
@@ -17,8 +17,9 @@ describe("resolveLocalVitestMaxWorkers", () => {
           loadAverage1m: 0,
           totalMemoryBytes: 64 * 1024 ** 3,
         },
+        "threads",
       ),
-    ).toBe(3);
+    ).toBe(2);
   });
 
   it("lets OPENCLAW_VITEST_MAX_WORKERS override the inferred cap", () => {
@@ -60,8 +61,9 @@ describe("resolveLocalVitestMaxWorkers", () => {
           loadAverage1m: 0,
           totalMemoryBytes: 16 * 1024 ** 3,
         },
+        "threads",
       ),
-    ).toBe(2);
+    ).toBe(1);
   });
 
   it("lets roomy hosts use more local parallelism", () => {
@@ -73,8 +75,9 @@ describe("resolveLocalVitestMaxWorkers", () => {
           loadAverage1m: 0,
           totalMemoryBytes: 128 * 1024 ** 3,
         },
+        "threads",
       ),
-    ).toBe(4);
+    ).toBe(3);
   });
 
   it("backs off further when the host is already busy", () => {
@@ -86,8 +89,23 @@ describe("resolveLocalVitestMaxWorkers", () => {
           loadAverage1m: 16,
           totalMemoryBytes: 128 * 1024 ** 3,
         },
+        "threads",
       ),
-    ).toBe(2);
+    ).toBe(1);
+  });
+
+  it("keeps fork pools less conservative than thread pools on roomy hosts", () => {
+    expect(
+      resolveLocalVitestMaxWorkers(
+        {},
+        {
+          cpuCount: 16,
+          loadAverage1m: 0,
+          totalMemoryBytes: 128 * 1024 ** 3,
+        },
+        "forks",
+      ),
+    ).toBe(4);
   });
 });
 
diff --git a/test/vitest-scoped-config.test.ts b/test/vitest-scoped-config.test.ts
index a4706dac02d..94bc8c9444e 100644
--- a/test/vitest-scoped-config.test.ts
+++ b/test/vitest-scoped-config.test.ts
@@ -65,7 +65,11 @@ describe("createScopedVitestConfig", () => {
       setupFiles: ["test/setup.extensions.ts"],
     });
 
-    expect(config.test?.setupFiles).toEqual(["test/setup.extensions.ts"]);
+    expect(config.test?.setupFiles).toEqual([
+      "test/setup.ts",
+      "test/setup.extensions.ts",
+      "test/setup-openclaw-runtime.ts",
+    ]);
   });
 });
 
@@ -85,7 +89,7 @@ describe("scoped vitest configs", () => {
 
   it("defaults channel tests to non-isolated mode", () => {
     expect(defaultChannelsConfig.test?.isolate).toBe(false);
-    expect(defaultChannelsConfig.test?.pool).toBe("forks");
+    expect(defaultChannelsConfig.test?.pool).toBe("threads");
   });
 
   it("keeps the core channel lane limited to non-extension roots", () => {
@@ -121,7 +125,7 @@ describe("scoped vitest configs", () => {
 
   it("defaults extension tests to non-isolated mode", () => {
     expect(defaultExtensionsConfig.test?.isolate).toBe(false);
-    expect(defaultExtensionsConfig.test?.pool).toBe("forks");
+    expect(defaultExtensionsConfig.test?.pool).toBe("threads");
   });
 
   it("normalizes extension channel include patterns relative to the scoped dir", () => {
@@ -165,7 +169,11 @@ describe("scoped vitest configs", () => {
     expect(defaultChannelsConfig.test?.exclude).not.toContain(
       bundledPluginFile("telegram", "src/fetch.test.ts"),
     );
-    expect(defaultExtensionsConfig.test?.setupFiles).toEqual(["test/setup.extensions.ts"]);
+    expect(defaultExtensionsConfig.test?.setupFiles).toEqual([
+      "test/setup.ts",
+      "test/setup.extensions.ts",
+      "test/setup-openclaw-runtime.ts",
+    ]);
   });
 
   it("keeps provider plugin tests out of the shared extensions lane", () => {
diff --git a/vitest.shared.config.ts b/vitest.shared.config.ts
index 1f782386cbb..34ec87d641d 100644
--- a/vitest.shared.config.ts
+++ b/vitest.shared.config.ts
@@ -44,6 +44,7 @@ function detectVitestHostInfo(): Required<VitestHostInfo> {
 export function resolveLocalVitestMaxWorkers(
   env: Record<string, string | undefined> = process.env,
   system: VitestHostInfo = detectVitestHostInfo(),
+  pool: OpenClawVitestPool = resolveDefaultVitestPool(env),
 ): number {
   const override = parsePositiveInt(env.OPENCLAW_VITEST_MAX_WORKERS ?? env.OPENCLAW_TEST_WORKERS);
   if (override !== null) {
@@ -76,6 +77,19 @@ export function resolveLocalVitestMaxWorkers(
     inferred = Math.max(1, inferred - 1);
   }
 
+  if (pool === "threads") {
+    // Thread workers are faster per slot on the steady state, but their startup
+    // compile pressure is much burstier. Keep headroom so a second local Vitest
+    // run can start without immediately saturating the host.
+    inferred = Math.min(inferred, 4);
+    if (cpuCount >= 8) {
+      inferred = Math.max(1, inferred - 1);
+    }
+    if (loadRatio >= 0.5) {
+      inferred = Math.max(1, inferred - 1);
+    }
+  }
+
   return clamp(inferred, 1, 16);
 }
 
@@ -92,9 +106,9 @@ export function resolveDefaultVitestPool(
 const repoRoot = path.dirname(fileURLToPath(import.meta.url));
 const isCI = process.env.CI === "true" || process.env.GITHUB_ACTIONS === "true";
 const isWindows = process.platform === "win32";
-const localWorkers = resolveLocalVitestMaxWorkers();
-const ciWorkers = isWindows ? 2 : 3;
 const defaultPool = resolveDefaultVitestPool();
+const localWorkers = resolveLocalVitestMaxWorkers(process.env, detectVitestHostInfo(), defaultPool);
+const ciWorkers = isWindows ? 2 : 3;
 
 export const sharedVitestConfig = {
   resolve: {