From 987f4bba803b407c2dedeceed978b54b55332c53 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sun, 5 Apr 2026 13:29:28 +0100
Subject: [PATCH] test: make vitest worker caps deterministic

---
 src/infra/vitest-config.test.ts | 36 ++++++---------------------------
 vitest.shared.config.ts         | 24 ++++------------------
 2 files changed, 10 insertions(+), 50 deletions(-)

diff --git a/src/infra/vitest-config.test.ts b/src/infra/vitest-config.test.ts
index 3d083377bc5..8a558824cdb 100644
--- a/src/infra/vitest-config.test.ts
+++ b/src/infra/vitest-config.test.ts
@@ -7,12 +7,6 @@ import baseConfig, {
 } from "../../vitest.config.ts";
 import { parseVitestProcessStats } from "../../vitest.system-load.ts";
 
-const idleVitestStats = {
-  otherVitestRootCount: 0,
-  otherVitestWorkerCount: 0,
-  otherVitestCpuPercent: 0,
-} as const;
-
 describe("resolveLocalVitestMaxWorkers", () => {
   it("uses a moderate local worker cap on larger hosts", () => {
     expect(
@@ -26,7 +20,6 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 64 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(6);
   });
@@ -43,7 +36,6 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(2);
   });
@@ -60,7 +52,6 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(3);
   });
@@ -75,7 +66,6 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 16 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(2);
   });
@@ -90,7 +80,6 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(8);
   });
@@ -105,7 +94,6 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(2);
   });
@@ -120,54 +108,43 @@ describe("resolveLocalVitestMaxWorkers", () => {
           totalMemoryBytes: 256 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toBe(12);
   });
 });
 
 describe("resolveLocalVitestScheduling", () => {
-  it("scales back to half capacity when other Vitest work is already consuming most cores", () => {
+  it("scales back to half capacity when the host load is already saturated", () => {
     expect(
       resolveLocalVitestScheduling(
         {},
         {
           cpuCount: 16,
-          loadAverage1m: 0.5,
+          loadAverage1m: 16,
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        {
-          otherVitestRootCount: 2,
-          otherVitestWorkerCount: 12,
-          otherVitestCpuPercent: 1200,
-        },
       ),
     ).toEqual({
-      maxWorkers: 4,
+      maxWorkers: 2,
       fileParallelism: true,
       throttledBySystem: true,
     });
   });
 
-  it("keeps big hosts parallel under moderate contention", () => {
+  it("keeps big hosts parallel under moderate host contention", () => {
     expect(
       resolveLocalVitestScheduling(
         {},
         {
           cpuCount: 16,
-          loadAverage1m: 0.5,
+          loadAverage1m: 12,
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        {
-          otherVitestRootCount: 1,
-          otherVitestWorkerCount: 7,
-          otherVitestCpuPercent: 700,
-        },
       ),
     ).toEqual({
-      maxWorkers: 6,
+      maxWorkers: 5,
       fileParallelism: true,
       throttledBySystem: true,
     });
@@ -185,7 +162,6 @@ describe("resolveLocalVitestScheduling", () => {
           totalMemoryBytes: 128 * 1024 ** 3,
         },
         "threads",
-        idleVitestStats,
       ),
     ).toEqual({
       maxWorkers: 8,
diff --git a/vitest.shared.config.ts b/vitest.shared.config.ts
index cc02c2ba161..256f06183c6 100644
--- a/vitest.shared.config.ts
+++ b/vitest.shared.config.ts
@@ -7,11 +7,7 @@ import {
   BUNDLED_PLUGIN_TEST_GLOB,
 } from "./vitest.bundled-plugin-paths.ts";
 import { loadVitestExperimentalConfig } from "./vitest.performance-config.ts";
-import {
-  detectVitestProcessStats,
-  shouldPrintVitestThrottle,
-  type VitestProcessStats,
-} from "./vitest.system-load.ts";
+import { shouldPrintVitestThrottle } from "./vitest.system-load.ts";
 
 const clamp = (value: number, min: number, max: number) => Math.max(min, Math.min(max, value));
 
@@ -61,16 +57,14 @@ export function resolveLocalVitestMaxWorkers(
   env: Record<string, string | undefined> = process.env,
   system: VitestHostInfo = detectVitestHostInfo(),
   pool: OpenClawVitestPool = resolveDefaultVitestPool(env),
-  processStats: VitestProcessStats = detectVitestProcessStats(env),
 ): number {
-  return resolveLocalVitestScheduling(env, system, pool, processStats).maxWorkers;
+  return resolveLocalVitestScheduling(env, system, pool).maxWorkers;
 }
 
 export function resolveLocalVitestScheduling(
   env: Record<string, string | undefined> = process.env,
   system: VitestHostInfo = detectVitestHostInfo(),
   pool: OpenClawVitestPool = resolveDefaultVitestPool(env),
-  processStats: VitestProcessStats = detectVitestProcessStats(env),
 ): LocalVitestScheduling {
   const override = parsePositiveInt(env.OPENCLAW_VITEST_MAX_WORKERS ?? env.OPENCLAW_TEST_WORKERS);
   if (override !== null) {
@@ -134,14 +128,7 @@ export function resolveLocalVitestScheduling(
     };
   }
 
-  const totalCpuPercentCapacity = Math.max(100, cpuCount * 100);
-  const otherVitestCpuRatio = processStats.otherVitestCpuPercent / totalCpuPercentCapacity;
-  const otherVitestWorkerRatio = processStats.otherVitestWorkerCount / cpuCount;
-
-  const highSystemContention =
-    loadRatio >= 1 || otherVitestWorkerRatio >= 0.75 || otherVitestCpuRatio >= 0.75;
-
-  if (highSystemContention) {
+  if (loadRatio >= 1) {
     const maxWorkers = Math.max(1, Math.floor(inferred / 2));
     return {
       maxWorkers,
@@ -150,10 +137,7 @@ export function resolveLocalVitestScheduling(
     };
   }
 
-  const moderateSystemContention =
-    loadRatio >= 0.75 || otherVitestWorkerRatio >= 0.4 || otherVitestCpuRatio >= 0.4;
-
-  if (moderateSystemContention) {
+  if (loadRatio >= 0.75) {
     const maxWorkers = Math.max(2, Math.ceil(inferred * 0.75));
     return {
       maxWorkers,