diff --git a/src/commands/doctor-session-transcripts.test.ts b/src/commands/doctor-session-transcripts.test.ts
index 1d9b22ba9a2..7ef9c8e7d8f 100644
--- a/src/commands/doctor-session-transcripts.test.ts
+++ b/src/commands/doctor-session-transcripts.test.ts
@@ -14,6 +14,16 @@ import {
   repairBrokenSessionTranscriptFile,
 } from "./doctor-session-transcripts.js";
 
+function countNonEmptyLines(value: string): number {
+  let count = 0;
+  for (const line of value.split(/\r?\n/)) {
+    if (line) {
+      count += 1;
+    }
+  }
+  return count;
+}
+
 describe("doctor session transcript repair", () => {
   let root: string;
 
@@ -129,7 +139,7 @@ describe("doctor session transcript repair", () => {
     expect(title).toBe("Session transcripts");
     expect(message).toContain("duplicated prompt-rewrite branches");
     expect(message).toContain('Run "openclaw doctor --fix"');
-    expect((await fs.readFile(filePath, "utf-8")).split(/\r?\n/).filter(Boolean)).toHaveLength(3);
+    expect(countNonEmptyLines(await fs.readFile(filePath, "utf-8"))).toBe(3);
   });
 
   it("ignores ordinary branch history without internal runtime context", async () => {
@@ -152,6 +162,6 @@ describe("doctor session transcript repair", () => {
     const result = await repairBrokenSessionTranscriptFile({ filePath, shouldRepair: true });
 
     expect(result.broken).toBe(false);
-    expect((await fs.readFile(filePath, "utf-8")).split(/\r?\n/).filter(Boolean)).toHaveLength(3);
+    expect(countNonEmptyLines(await fs.readFile(filePath, "utf-8"))).toBe(3);
   });
 });
diff --git a/src/gateway/server-methods/server-methods.test.ts b/src/gateway/server-methods/server-methods.test.ts
index c49dede5266..9fa3b49f2db 100644
--- a/src/gateway/server-methods/server-methods.test.ts
+++ b/src/gateway/server-methods/server-methods.test.ts
@@ -31,6 +31,16 @@ vi.mock("../../commands/status.js", () => ({
   getStatusSummary: vi.fn().mockResolvedValue({ ok: true }),
 }));
 
+function countMatching<T>(items: readonly T[], predicate: (item: T) => boolean): number {
+  let count = 0;
+  for (const item of items) {
+    if (predicate(item)) {
+      count += 1;
+    }
+  }
+  return count;
+}
+
 describe("waitForAgentJob", () => {
   async function runLifecycleScenario(params: {
     runIdPrefix: string;
@@ -1212,7 +1222,7 @@ describe("exec approval handlers", () => {
 
     expect(firstResolveRespond).toHaveBeenCalledWith(true, { ok: true }, undefined);
     expect(repeatResolveRespond).toHaveBeenCalledWith(true, { ok: true }, undefined);
-    expect(broadcasts.filter((entry) => entry.event === "exec.approval.resolved")).toHaveLength(
+    expect(countMatching(broadcasts, (entry) => entry.event === "exec.approval.resolved")).toBe(
       resolvedBroadcastCount,
     );
     expect(conflictingResolveRespond).toHaveBeenCalledWith(
diff --git a/src/plugins/loader.test.ts b/src/plugins/loader.test.ts
index 08bad34ba37..d39dfa2f0ad 100644
--- a/src/plugins/loader.test.ts
+++ b/src/plugins/loader.test.ts
@@ -4282,7 +4282,7 @@ module.exports = { id: "throws-after-import", register() {} };`,
       },
     });
 
-    expect(registry.services.filter((entry) => entry.service.id === "shared-service")).toHaveLength(
+    expect(countMatching(registry.services, (entry) => entry.service.id === "shared-service")).toBe(
       1,
     );
     expectNoDiagnosticContaining({
diff --git a/src/secrets/audit.test.ts b/src/secrets/audit.test.ts
index 43564a141fa..b2b69b0cffa 100644
--- a/src/secrets/audit.test.ts
+++ b/src/secrets/audit.test.ts
@@ -18,6 +18,16 @@ type AuditFixture = {
 const OPENAI_API_KEY_MARKER = "OPENAI_API_KEY"; // pragma: allowlist secret
 const MAX_AUDIT_MODELS_JSON_BYTES = 5 * 1024 * 1024;
 
+function countNonEmptyLines(value: string): number {
+  let count = 0;
+  for (const line of value.split("\n")) {
+    if (line.trim().length > 0) {
+      count += 1;
+    }
+  }
+  return count;
+}
+
 async function writeJsonFile(filePath: string, value: unknown): Promise<void> {
   await fs.writeFile(filePath, `${JSON.stringify(value, null, 2)}\n`, "utf8");
 }
@@ -334,7 +344,7 @@ describe("secrets audit", () => {
     expect(report.summary.unresolvedRefCount).toBe(0);
 
     const callLog = await fs.readFile(execLogPath, "utf8");
-    const callCount = callLog.split("\n").filter((line) => line.trim().length > 0).length;
+    const callCount = countNonEmptyLines(callLog);
     expect(callCount).toBe(1);
   });
 
@@ -398,7 +408,7 @@ describe("secrets audit", () => {
     expect(report.summary.unresolvedRefCount).toBeGreaterThanOrEqual(2);
 
     const callLog = await fs.readFile(execLogPath, "utf8");
-    const callCount = callLog.split("\n").filter((line) => line.trim().length > 0).length;
+    const callCount = countNonEmptyLines(callLog);
     expect(callCount).toBe(1);
   });
 
diff --git a/test/scripts/parallels-smoke-model.test.ts b/test/scripts/parallels-smoke-model.test.ts
index eb4c8bc821e..d538f1d22da 100644
--- a/test/scripts/parallels-smoke-model.test.ts
+++ b/test/scripts/parallels-smoke-model.test.ts
@@ -35,6 +35,16 @@ const TS_PATHS = {
 
 const OS_TS_PATHS = [TS_PATHS.linux, TS_PATHS.macos, TS_PATHS.windows];
 
+function countNonEmptyLines(value: string): number {
+  let count = 0;
+  for (const line of value.split("\n")) {
+    if (line) {
+      count += 1;
+    }
+  }
+  return count;
+}
+
 function runTsEval(source: string, env: Record<string, string> = {}) {
   return execFileSync("node", ["--import", "tsx", "--input-type=module", "--eval", source], {
     encoding: "utf8",
@@ -79,7 +89,7 @@ describe("Parallels smoke model selection", () => {
       } else {
         expect(wrapper, wrapperPath).toContain(TS_PATHS[platform as "linux" | "macos" | "windows"]);
       }
-      expect(wrapper.split("\n").filter(Boolean).length).toBeLessThanOrEqual(5);
+      expect(countNonEmptyLines(wrapper)).toBeLessThanOrEqual(5);
     }
   });
 
diff --git a/test/vitest-unit-fast-config.test.ts b/test/vitest-unit-fast-config.test.ts
index b6c64b8532e..5c62b7bb9fc 100644
--- a/test/vitest-unit-fast-config.test.ts
+++ b/test/vitest-unit-fast-config.test.ts
@@ -20,6 +20,16 @@ function requireTestConfig<T extends { test?: unknown }>(config: T): NonNullable
   return config.test as NonNullable<T["test"]>;
 }
 
+function countMatching<T>(items: readonly T[], predicate: (item: T) => boolean): number {
+  let count = 0;
+  for (const item of items) {
+    if (predicate(item)) {
+      count += 1;
+    }
+  }
+  return count;
+}
+
 describe("unit-fast vitest lane", () => {
   it("runs cache-friendly tests without the reset-heavy runner or runtime setup", () => {
     const config = createUnitFastVitestConfig({});
@@ -122,7 +132,7 @@ describe("unit-fast vitest lane", () => {
 
     expect(currentCandidates.length).toBeGreaterThanOrEqual(unitFastTestFiles.length);
     expect(broadCandidates.length).toBeGreaterThan(currentCandidates.length);
-    expect(broadAnalysis.filter((entry) => entry.unitFast).length).toBeGreaterThan(
+    expect(countMatching(broadAnalysis, (entry) => entry.unitFast)).toBeGreaterThan(
       unitFastTestFiles.length,
     );
   });