diff --git a/src/agents/bash-tools.exec-runtime.pty-fallback.test.ts b/src/agents/bash-tools.exec-runtime.pty-fallback.test.ts
index 3b8708a025b..4d1c5a7c6cd 100644
--- a/src/agents/bash-tools.exec-runtime.pty-fallback.test.ts
+++ b/src/agents/bash-tools.exec-runtime.pty-fallback.test.ts
@@ -141,11 +141,13 @@ test("exec emits bounded process diagnostics without command text", async () =>
     const event = events.find(
       (item): item is DiagnosticExecProcessCompletedEvent => item.type === "exec.process.completed",
     );
-    expect(event).toBeDefined();
-    expect(event?.type).toBe("exec.process.completed");
-    expect(event?.target).toBe("host");
-    expect(event?.mode).toBe("child");
-    expect(event?.outcome).toBe("completed");
+    if (!event) {
+      throw new Error("Expected exec process completed event");
+    }
+    expect(event.type).toBe("exec.process.completed");
+    expect(event.target).toBe("host");
+    expect(event.mode).toBe("child");
+    expect(event.outcome).toBe("completed");
     expect(typeof event?.durationMs).toBe("number");
     expect(event?.commandLength).toBe(command.length);
     expect(event?.exitCode).toBe(0);
diff --git a/src/agents/btw.test.ts b/src/agents/btw.test.ts
index 58ec37ad98a..3b8f6aa1e0d 100644
--- a/src/agents/btw.test.ts
+++ b/src/agents/btw.test.ts
@@ -280,8 +280,10 @@ function streamContext(callIndex = 0): {
 
 function contextMessages(context: unknown): Array<Record<string, unknown>> {
   const messages = (context as { messages?: Array<Record<string, unknown>> }).messages;
-  expect(messages).toBeDefined();
-  return messages ?? [];
+  if (!messages) {
+    throw new Error("Expected BTW context messages");
+  }
+  return messages;
 }
 
 function expectTextBlockContains(block: unknown, text: string): void {
@@ -752,7 +754,9 @@ describe("runBtwSideQuestion", () => {
           `<btw_side_question>\n${MATH_QUESTION}\n</btw_side_question>`,
         ),
     );
-    expect(sideQuestionMessage).toBeDefined();
+    if (!sideQuestionMessage) {
+      throw new Error("Expected BTW side question message");
+    }
   });
 
   it("uses the in-flight prompt as background only when there is no prior transcript context", async () => {
@@ -792,7 +796,9 @@ describe("runBtwSideQuestion", () => {
           "Ignore any unfinished task in the conversation while answering it.",
         ),
     );
-    expect(sideQuestionMessage).toBeDefined();
+    if (!sideQuestionMessage) {
+      throw new Error("Expected isolated side question message");
+    }
   });
 
   it("branches away from an unresolved trailing user turn before building BTW context", async () => {
diff --git a/src/agents/model-fallback.probe.test.ts b/src/agents/model-fallback.probe.test.ts
index 868418c3b2c..a4bfa97ec5d 100644
--- a/src/agents/model-fallback.probe.test.ts
+++ b/src/agents/model-fallback.probe.test.ts
@@ -157,7 +157,9 @@ function expectRecordWithFields(
   const matching = records.find((record) =>
     Object.entries(expected).every(([key, value]) => record[key] === value),
   );
-  expect(matching, `expected matching record for ${JSON.stringify(expected)}`).toBeDefined();
+  if (!matching) {
+    throw new Error(`Expected matching record for ${JSON.stringify(expected)}`);
+  }
 }
 
 async function expectProbeFailureFallsBack({
diff --git a/src/agents/openclaw-gateway-tool.test.ts b/src/agents/openclaw-gateway-tool.test.ts
index 2a0bf6733ad..0465d8995e0 100644
--- a/src/agents/openclaw-gateway-tool.test.ts
+++ b/src/agents/openclaw-gateway-tool.test.ts
@@ -66,7 +66,9 @@ function expectGatewayCallFields(
   expectedParams: Record<string, unknown>,
 ): Record<string, unknown> {
   const [, , params] = gatewayCall(method);
-  expect(params).toBeDefined();
+  if (params === undefined) {
+    throw new Error(`Expected gateway call params for ${method}`);
+  }
   const record = params as Record<string, unknown>;
   for (const [key, value] of Object.entries(expectedParams)) {
     expect(record[key]).toEqual(value);
diff --git a/src/agents/pi-embedded-runner/compact.hooks.test.ts b/src/agents/pi-embedded-runner/compact.hooks.test.ts
index c9b7206098c..da1382b86cb 100644
--- a/src/agents/pi-embedded-runner/compact.hooks.test.ts
+++ b/src/agents/pi-embedded-runner/compact.hooks.test.ts
@@ -381,13 +381,17 @@ describe("compactEmbeddedPiSessionDirect hooks", () => {
       ([provider, modelId]) => provider === "openai" && modelId === "gpt-primary",
     );
     expect(primaryCall[2]).toBeTypeOf("string");
-    expect(primaryCall[3]).toBeDefined();
+    if (primaryCall[3] === undefined) {
+      throw new Error("Expected primary resolve-model options");
+    }
     const fallbackCall = findMockCall(
       resolveModelMock,
       ([provider, modelId]) => provider === "anthropic" && modelId === "claude-fallback",
     );
     expect(fallbackCall[2]).toBeTypeOf("string");
-    expect(fallbackCall[3]).toBeDefined();
+    if (fallbackCall[3] === undefined) {
+      throw new Error("Expected fallback resolve-model options");
+    }
   });
 
   it("keeps compaction fallback selection ephemeral", async () => {
@@ -442,13 +446,17 @@ describe("compactEmbeddedPiSessionDirect hooks", () => {
       ([provider, modelId]) => provider === "openai" && modelId === "gpt-primary",
     );
     expect(primaryCall[2]).toBeTypeOf("string");
-    expect(primaryCall[3]).toBeDefined();
+    if (primaryCall[3] === undefined) {
+      throw new Error("Expected primary resolve-model options");
+    }
     const fallbackCall = findMockCall(
       resolveModelMock,
       ([provider, modelId]) => provider === "anthropic" && modelId === "claude-fallback",
     );
     expect(fallbackCall[2]).toBeTypeOf("string");
-    expect(fallbackCall[3]).toBeDefined();
+    if (fallbackCall[3] === undefined) {
+      throw new Error("Expected fallback resolve-model options");
+    }
     expect(config).toEqual(configBefore);
   });
 
@@ -490,7 +498,9 @@ describe("compactEmbeddedPiSessionDirect hooks", () => {
     expect(mockCallArg(resolveModelMock)).toBe("azure");
     expect(mockCallArg(resolveModelMock, 0, 1)).toBe("compact-primary");
     expect(mockCallArg(resolveModelMock, 0, 2)).toBeTypeOf("string");
-    expect(mockCallArg(resolveModelMock, 0, 3)).toBeDefined();
+    if (mockCallArg(resolveModelMock, 0, 3) === undefined) {
+      throw new Error("Expected resolve-model options");
+    }
   });
 
   it("preserves compaction failure status and code metadata", async () => {
@@ -1266,7 +1276,9 @@ describe("compactEmbeddedPiSession hooks (ownsCompaction engine)", () => {
     expect(mockCallArg(resolveModelMock)).toBe("anthropic");
     expect(mockCallArg(resolveModelMock, 0, 1)).toBe("claude-opus-4-6");
     expect(mockCallArg(resolveModelMock, 0, 2)).toBeTypeOf("string");
-    expect(mockCallArg(resolveModelMock, 0, 3)).toBeDefined();
+    if (mockCallArg(resolveModelMock, 0, 3) === undefined) {
+      throw new Error("Expected resolve-model options");
+    }
     const compactArg = mockCallArg(contextEngineCompactMock) as {
       runtimeContext?: Record<string, unknown>;
     };
@@ -1299,7 +1311,9 @@ describe("compactEmbeddedPiSession hooks (ownsCompaction engine)", () => {
 
     expect(result.ok).toBe(true);
     const harnessArg = mockCallArg(maybeCompactAgentHarnessSessionMock) as Record<string, unknown>;
-    expect(harnessArg.contextEngine).toBeDefined();
+    if (harnessArg.contextEngine === undefined) {
+      throw new Error("Expected compact harness context engine");
+    }
     expect(harnessArg.contextTokenBudget).toBeTypeOf("number");
     expectRecordFields(harnessArg.contextEngineRuntimeContext, {
       sessionKey: TEST_SESSION_KEY,
diff --git a/src/agents/pi-embedded-runner/model.skip-pi-discovery-hooks.test.ts b/src/agents/pi-embedded-runner/model.skip-pi-discovery-hooks.test.ts
index 753621c8d3b..ddf9757b0e0 100644
--- a/src/agents/pi-embedded-runner/model.skip-pi-discovery-hooks.test.ts
+++ b/src/agents/pi-embedded-runner/model.skip-pi-discovery-hooks.test.ts
@@ -78,7 +78,6 @@ describe("resolveModelAsync skipPiDiscovery runtime hooks", () => {
     });
 
     expect(result.error).toBeUndefined();
-    expect(result.model).toBeDefined();
     if (!result.model) {
       throw new Error("Expected resolved model");
     }
diff --git a/src/agents/pi-tools.read.host-edit-access.test.ts b/src/agents/pi-tools.read.host-edit-access.test.ts
index 94ad2c58b29..dbc467c6a0f 100644
--- a/src/agents/pi-tools.read.host-edit-access.test.ts
+++ b/src/agents/pi-tools.read.host-edit-access.test.ts
@@ -66,7 +66,6 @@ describe("createHostWorkspaceEditTool host access mapping", () => {
       // By resolving silently the subsequent readFile call surfaces the real
       // "Path escapes workspace root" / "outside-workspace" error instead.
       const operations = mocks.operations;
-      expect(operations).toBeDefined();
       if (!operations) {
         throw new Error("Expected workspace edit operations to be registered.");
       }
diff --git a/src/agents/provider-local-service.test.ts b/src/agents/provider-local-service.test.ts
index 23e871d0ea0..9b08f7e27af 100644
--- a/src/agents/provider-local-service.test.ts
+++ b/src/agents/provider-local-service.test.ts
@@ -89,9 +89,11 @@ describe("provider local service", () => {
 
     const lease = await ensureModelProviderLocalService(model);
 
-    expect(lease).toBeDefined();
+    if (!lease) {
+      throw new Error("Expected provider local service lease");
+    }
     expect((await fetch(healthUrl)).ok).toBe(true);
-    lease?.release();
+    lease.release();
     await waitForProbeFailure(healthUrl);
   });
 
@@ -121,7 +123,9 @@ describe("provider local service", () => {
       "X-Tenant": "acme",
     });
 
-    expect(lease).toBeDefined();
+    if (!lease) {
+      throw new Error("Expected provider local service lease");
+    }
     expect((await fetch(healthUrl)).status).toBe(401);
     expect(
       (
@@ -283,9 +287,11 @@ describe("provider local service", () => {
       expect((await fetch(healthUrl)).status).toBe(503);
 
       const secondLease = await ensureModelProviderLocalService(model);
-      expect(secondLease).toBeDefined();
+      if (!secondLease) {
+        throw new Error("Expected restarted provider local service lease");
+      }
       expect((await fetch(healthUrl)).ok).toBe(true);
-      secondLease?.release();
+      secondLease.release();
 
       const starts = (await fs.readFile(startsPath, "utf8")).trim().split("\n");
       expect(starts).toHaveLength(2);
diff --git a/src/agents/subagent-spawn.depth-limits.test.ts b/src/agents/subagent-spawn.depth-limits.test.ts
index 72dc4469bad..feb7fc8c4c1 100644
--- a/src/agents/subagent-spawn.depth-limits.test.ts
+++ b/src/agents/subagent-spawn.depth-limits.test.ts
@@ -121,7 +121,6 @@ describe("subagent spawn depth + child limits", () => {
     expect(accepted.childSessionKey).toMatch(/^agent:main:subagent:/);
 
     const childSession = persistedStore?.[accepted.childSessionKey];
-    expect(childSession).toBeDefined();
     if (!childSession) {
       throw new Error("Expected persisted child session");
     }
diff --git a/src/agents/tools/message-tool.test.ts b/src/agents/tools/message-tool.test.ts
index bea295a5183..ca1dfa6c7b1 100644
--- a/src/agents/tools/message-tool.test.ts
+++ b/src/agents/tools/message-tool.test.ts
@@ -1005,11 +1005,13 @@ describe("message tool schema scoping", () => {
     });
 
     const context = seenContexts.find((item) => item.phase === "describeMessageTool");
-    expect(context).toBeDefined();
-    expect(context?.currentChannelProvider).toBe("discord");
-    expect(context?.currentChannelId).toBe("channel:123");
-    expect(context?.currentThreadTs).toBe("thread-456");
-    expect(context?.currentMessageId).toBe("msg-789");
+    if (!context) {
+      throw new Error("Expected describeMessageTool discovery context");
+    }
+    expect(context.currentChannelProvider).toBe("discord");
+    expect(context.currentChannelId).toBe("channel:123");
+    expect(context.currentThreadTs).toBe("thread-456");
+    expect(context.currentMessageId).toBe("msg-789");
     expect(context?.accountId).toBe("ops");
     expect(context?.sessionKey).toBe("agent:alpha:main");
     expect(context?.sessionId).toBe("session-123");
diff --git a/src/agents/tools/music-generate-background.test.ts b/src/agents/tools/music-generate-background.test.ts
index 605f99b8c24..e9d6acfc992 100644
--- a/src/agents/tools/music-generate-background.test.ts
+++ b/src/agents/tools/music-generate-background.test.ts
@@ -36,7 +36,9 @@ function expectReplyInstructionContains(text: string) {
   const event = getDeliveredInternalEvents().find(
     (item) => typeof item.replyInstruction === "string" && item.replyInstruction.includes(text),
   );
-  expect(event).toBeDefined();
+  if (!event) {
+    throw new Error(`Expected reply instruction containing ${text}`);
+  }
 }
 
 describe("music generate background helpers", () => {
diff --git a/src/agents/tools/video-generate-tool.test.ts b/src/agents/tools/video-generate-tool.test.ts
index f5b1ad316d2..19f6cc49b2e 100644
--- a/src/agents/tools/video-generate-tool.test.ts
+++ b/src/agents/tools/video-generate-tool.test.ts
@@ -148,14 +148,18 @@ function mockSavedVideoResult(fileName = "out.mp4") {
 }
 
 function resultDetails(result: { details?: unknown }): Record<string, unknown> {
-  expect(result.details).toBeDefined();
+  if (result.details === undefined) {
+    throw new Error("Expected video generation result details");
+  }
   expect(typeof result.details).toBe("object");
   return result.details as Record<string, unknown>;
 }
 
 function firstMockCallArg(mock: { mock: { calls: unknown[][] } }): unknown {
   const firstCall = mock.mock.calls[0];
-  expect(firstCall).toBeDefined();
+  if (!firstCall) {
+    throw new Error("Expected first mock call");
+  }
   return firstCall[0];
 }