diff --git a/extensions/codex/src/app-server/run-attempt.test.ts b/extensions/codex/src/app-server/run-attempt.test.ts
index af2031fa68e..d6858e6a355 100644
--- a/extensions/codex/src/app-server/run-attempt.test.ts
+++ b/extensions/codex/src/app-server/run-attempt.test.ts
@@ -1882,7 +1882,7 @@ describe("runCodexAppServerAttempt", () => {
         },
       ]),
     );
-    expect(agentEvents.filter((event) => event.stream === "assistant")).toEqual([]);
+    expect(agentEvents.some((event) => event.stream === "assistant")).toBe(false);
     expect(agentEnd).toHaveBeenCalledWith(
       expect.objectContaining({
         success: false,
diff --git a/extensions/memory-core/src/memory/qmd-manager.test.ts b/extensions/memory-core/src/memory/qmd-manager.test.ts
index 6baee0c0d77..aa5a467358c 100644
--- a/extensions/memory-core/src/memory/qmd-manager.test.ts
+++ b/extensions/memory-core/src/memory/qmd-manager.test.ts
@@ -2974,7 +2974,7 @@ describe("QmdMemoryManager", () => {
     await manager.search("hello again", { sessionKey: "agent:main:slack:dm:u123" });
 
     expect(selectors.length).toBeGreaterThanOrEqual(2);
-    expect(selectors.filter((selector) => selector !== "qmd.query")).toEqual([]);
+    expect(selectors.every((selector) => selector === "qmd.query")).toBe(true);
     expect(logWarnMock).not.toHaveBeenCalledWith(
       expect.stringContaining("falling back to v1 tool names"),
     );
@@ -3043,7 +3043,7 @@ describe("QmdMemoryManager", () => {
 
     expect(runMcporterSpy).toHaveBeenCalled();
     expect(selectors.length).toBeGreaterThanOrEqual(1);
-    expect(selectors.filter((selector) => selector !== "qmd.query")).toEqual([]);
+    expect(selectors.every((selector) => selector === "qmd.query")).toBe(true);
     expect(logWarnMock).not.toHaveBeenCalledWith(
       expect.stringContaining("falling back to v1 tool names"),
     );
diff --git a/src/agents/harness/v2.test.ts b/src/agents/harness/v2.test.ts
index 3170ce4cf62..d5086a017a1 100644
--- a/src/agents/harness/v2.test.ts
+++ b/src/agents/harness/v2.test.ts
@@ -181,7 +181,7 @@ describe("AgentHarness V2 compatibility adapter", () => {
       "harness.run.started",
       "harness.run.completed",
     ]);
-    expect(diagnostics.events.filter(({ metadata }) => !metadata.trusted)).toEqual([]);
+    expect(diagnostics.events.every(({ metadata }) => metadata.trusted)).toBe(true);
     expect(diagnostics.events[1]?.event).toMatchObject({
       type: "harness.run.completed",
       runId: "run-1",
@@ -238,7 +238,7 @@ describe("AgentHarness V2 compatibility adapter", () => {
       "harness.run.started",
       "harness.run.error",
     ]);
-    expect(diagnostics.events.filter(({ metadata }) => !metadata.trusted)).toEqual([]);
+    expect(diagnostics.events.every(({ metadata }) => metadata.trusted)).toBe(true);
     expect(diagnostics.events[1]?.event).toMatchObject({
       type: "harness.run.error",
       phase: "send",
diff --git a/src/agents/openai-ws-stream.test.ts b/src/agents/openai-ws-stream.test.ts
index c65f872059a..b90caff3e74 100644
--- a/src/agents/openai-ws-stream.test.ts
+++ b/src/agents/openai-ws-stream.test.ts
@@ -1458,7 +1458,7 @@ describe("buildAssistantMessageFromResponse", () => {
     };
 
     expect(msg.phase).toBeUndefined();
-    expect(msg.content.filter((part) => part.type === "text")).toEqual([]);
+    expect(msg.content.some((part) => part.type === "text")).toBe(false);
     expect(msg.content).toMatchObject([{ type: "toolCall", name: "exec" }]);
     expect(msg.stopReason).toBe("toolUse");
   });
@@ -2182,7 +2182,7 @@ describe("createOpenAIWebSocketStreamFn", () => {
         }
       | undefined;
     expect(doneEvent?.message.phase).toBeUndefined();
-    expect(doneEvent?.message.content?.filter((part) => part.type === "text")).toEqual([]);
+    expect(doneEvent?.message.content?.some((part) => part.type === "text")).toBe(false);
     expect(doneEvent?.message.stopReason).toBe("toolUse");
   });
 
@@ -2752,7 +2752,7 @@ describe("createOpenAIWebSocketStreamFn", () => {
     expect(streamSimpleCalls.length).toBeGreaterThanOrEqual(1);
     expect(manager.closeCallCount).toBeGreaterThanOrEqual(1);
     expect(events.filter((event) => event.type === "start")).toHaveLength(1);
-    expect(events.filter((event) => event.type === "error")).toEqual([]);
+    expect(events.some((event) => event.type === "error")).toBe(false);
     const doneEvent = events.find((event) => event.type === "done");
     expect(doneEvent?.message?.content?.[0]?.text).toBe("http fallback response");
   });
@@ -2786,7 +2786,7 @@ describe("createOpenAIWebSocketStreamFn", () => {
     expect(streamSimpleCalls.length).toBeGreaterThanOrEqual(1);
     expect(manager.closeCallCount).toBeGreaterThanOrEqual(1);
     expect(events.filter((event) => event.type === "start")).toHaveLength(1);
-    expect(events.filter((event) => event.type === "error")).toEqual([]);
+    expect(events.some((event) => event.type === "error")).toBe(false);
     const doneEvent = events.find((event) => event.type === "done");
     expect(doneEvent?.message?.content?.[0]?.text).toBe("http fallback response");
   });
diff --git a/src/agents/pi-embedded-runner/context-engine-maintenance.test.ts b/src/agents/pi-embedded-runner/context-engine-maintenance.test.ts
index b920078c115..4c67541cbd6 100644
--- a/src/agents/pi-embedded-runner/context-engine-maintenance.test.ts
+++ b/src/agents/pi-embedded-runner/context-engine-maintenance.test.ts
@@ -607,7 +607,7 @@ describe("runContextEngineMaintenance", () => {
           (task) => task.taskKind === TURN_MAINTENANCE_TASK_KIND,
         );
         expect(completedTasks).toHaveLength(2);
-        expect(completedTasks.filter((task) => task.status !== "succeeded")).toEqual([]);
+        expect(completedTasks.every((task) => task.status === "succeeded")).toBe(true);
 
         await foregroundTurn;
       } finally {
@@ -684,7 +684,7 @@ describe("runContextEngineMaintenance", () => {
           (task) => task.taskKind === TURN_MAINTENANCE_TASK_KIND,
         );
         expect(tasks).toHaveLength(2);
-        expect(tasks.filter((task) => task.status !== "succeeded")).toEqual([]);
+        expect(tasks.every((task) => task.status === "succeeded")).toBe(true);
       } finally {
         vi.useRealTimers();
       }
diff --git a/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts b/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
index 8e2fda36bc8..e3db6aa8ab9 100644
--- a/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
@@ -631,7 +631,7 @@ describe("runEmbeddedAttempt context engine sessionKey forwarding", () => {
       .trim()
       .split("\n")
       .map((line) => JSON.parse(line) as TrajectoryEvent);
-    expect(trajectoryEvents.filter((event) => event.type === "prompt.submitted")).toEqual([]);
+    expect(trajectoryEvents.some((event) => event.type === "prompt.submitted")).toBe(false);
     expect(trajectoryEvents).toEqual(
       expect.arrayContaining([
         expect.objectContaining({
diff --git a/src/agents/pi-embedded-runner/run/idle-timeout-breaker.test.ts b/src/agents/pi-embedded-runner/run/idle-timeout-breaker.test.ts
index 4d4ee31c0c6..6034ffdd033 100644
--- a/src/agents/pi-embedded-runner/run/idle-timeout-breaker.test.ts
+++ b/src/agents/pi-embedded-runner/run/idle-timeout-breaker.test.ts
@@ -79,7 +79,7 @@ describe("stepIdleTimeoutBreaker (#76293)", () => {
       ],
       { cap: 0 },
     );
-    expect(steps.filter((step) => step.tripped)).toEqual([]);
+    expect(steps.some((step) => step.tripped)).toBe(false);
     expect(steps.at(-1)?.consecutive).toBe(7);
   });
 
@@ -94,7 +94,7 @@ describe("stepIdleTimeoutBreaker (#76293)", () => {
         outputTokens: 220,
       })),
     );
-    expect(steps.filter((step) => step.tripped)).toEqual([]);
+    expect(steps.some((step) => step.tripped)).toBe(false);
     expect(steps.at(-1)?.consecutive).toBe(0);
   });