diff --git a/extensions/canvas/src/host/file-resolver.test.ts b/extensions/canvas/src/host/file-resolver.test.ts
index 800a189b318..819d62306ff 100644
--- a/extensions/canvas/src/host/file-resolver.test.ts
+++ b/extensions/canvas/src/host/file-resolver.test.ts
@@ -4,6 +4,8 @@ import { resolvePreferredOpenClawTmpDir, withTempWorkspace } from "openclaw/plug
 import { describe, expect, it } from "vitest";
 import { normalizeUrlPath, resolveFileWithinRoot } from "./file-resolver.js";
 
+type ResolvedFile = NonNullable<Awaited<ReturnType<typeof resolveFileWithinRoot>>>;
+
 async function withCanvasTemp<T>(prefix: string, run: (dir: string) => Promise<T>): Promise<T> {
   return await withTempWorkspace(
     { rootDir: resolvePreferredOpenClawTmpDir(), prefix },
@@ -11,6 +13,16 @@ async function withCanvasTemp<T>(prefix: string, run: (dir: string) => Promise<T
   );
 }
 
+function expectResolvedFile(
+  result: Awaited<ReturnType<typeof resolveFileWithinRoot>>,
+): ResolvedFile {
+  expect(result).toEqual(expect.objectContaining({ handle: expect.any(Object) }));
+  if (result === null) {
+    throw new Error("Expected resolved file within root");
+  }
+  return result;
+}
+
 describe("resolveFileWithinRoot", () => {
   it("normalizes URL paths", () => {
     expect(normalizeUrlPath("/nested/../file.txt")).toBe("/file.txt");
@@ -23,11 +35,11 @@ describe("resolveFileWithinRoot", () => {
       await fs.writeFile(path.join(root, "docs", "index.html"), "<h1>docs</h1>");
 
       const result = await resolveFileWithinRoot(root, "/docs");
-      expect(result).not.toBeNull();
+      const resolved = expectResolvedFile(result);
       try {
-        await expect(result?.handle.readFile({ encoding: "utf8" })).resolves.toBe("<h1>docs</h1>");
+        await expect(resolved.handle.readFile({ encoding: "utf8" })).resolves.toBe("<h1>docs</h1>");
       } finally {
-        await result?.handle.close().catch(() => {});
+        await resolved.handle.close().catch(() => {});
       }
     });
   });
diff --git a/extensions/codex/src/app-server/trajectory.test.ts b/extensions/codex/src/app-server/trajectory.test.ts
index 91b0e3a3076..ab611db3a73 100644
--- a/extensions/codex/src/app-server/trajectory.test.ts
+++ b/extensions/codex/src/app-server/trajectory.test.ts
@@ -8,6 +8,8 @@ import {
   resolveCodexTrajectoryPointerFlags,
 } from "./trajectory.js";
 
+type CodexTrajectoryRecorder = NonNullable<ReturnType<typeof createCodexTrajectoryRecorder>>;
+
 const tempDirs: string[] = [];
 
 function makeTempDir(): string {
@@ -22,6 +24,16 @@ afterEach(() => {
   }
 });
 
+function expectTrajectoryRecorder(
+  recorder: ReturnType<typeof createCodexTrajectoryRecorder>,
+): CodexTrajectoryRecorder {
+  expect(recorder).toEqual(expect.objectContaining({ recordEvent: expect.any(Function) }));
+  if (recorder === null) {
+    throw new Error("Expected Codex trajectory recorder");
+  }
+  return recorder;
+}
+
 describe("Codex trajectory recorder", () => {
   it("keeps write flags usable when O_NOFOLLOW is unavailable", () => {
     const constants = {
@@ -52,13 +64,13 @@ describe("Codex trajectory recorder", () => {
       env: {},
     });
 
-    expect(recorder).not.toBeNull();
-    recorder?.recordEvent("session.started", {
+    const trajectoryRecorder = expectTrajectoryRecorder(recorder);
+    trajectoryRecorder.recordEvent("session.started", {
       apiKey: "secret",
       headers: [{ name: "Authorization", value: "Bearer sk-test-secret-token" }],
       command: "curl -H 'Authorization: Bearer sk-other-secret-token'",
     });
-    await recorder?.flush();
+    await trajectoryRecorder.flush();
 
     const filePath = path.join(tmpDir, "session.trajectory.jsonl");
     const content = fs.readFileSync(filePath, "utf8");
@@ -82,8 +94,9 @@ describe("Codex trajectory recorder", () => {
       env: { OPENCLAW_TRAJECTORY_DIR: tmpDir },
     });
 
-    recorder?.recordEvent("session.started");
-    await recorder?.flush();
+    const trajectoryRecorder = expectTrajectoryRecorder(recorder);
+    trajectoryRecorder.recordEvent("session.started");
+    await trajectoryRecorder.flush();
 
     expect(fs.existsSync(path.join(tmpDir, "___evil_session.jsonl"))).toBe(true);
   });
@@ -119,8 +132,9 @@ describe("Codex trajectory recorder", () => {
       env: {},
     });
 
-    recorder?.recordEvent("session.started");
-    await recorder?.flush();
+    const trajectoryRecorder = expectTrajectoryRecorder(recorder);
+    trajectoryRecorder.recordEvent("session.started");
+    await trajectoryRecorder.flush();
 
     expect(fs.existsSync(path.join(targetDir, "session.trajectory.jsonl"))).toBe(false);
   });
@@ -137,12 +151,13 @@ describe("Codex trajectory recorder", () => {
       env: {},
     });
 
-    recorder?.recordEvent("context.compiled", {
+    const trajectoryRecorder = expectTrajectoryRecorder(recorder);
+    trajectoryRecorder.recordEvent("context.compiled", {
       fields: Object.fromEntries(
         Array.from({ length: 100 }, (_, index) => [`field-${index}`, "x".repeat(3_000)]),
       ),
     });
-    await recorder?.flush();
+    await trajectoryRecorder.flush();
 
     const parsed = JSON.parse(
       fs.readFileSync(path.join(tmpDir, "session.trajectory.jsonl"), "utf8"),
diff --git a/extensions/discord/src/monitor/presence.test.ts b/extensions/discord/src/monitor/presence.test.ts
index 1ea06f9dc28..6c1d117105b 100644
--- a/extensions/discord/src/monitor/presence.test.ts
+++ b/extensions/discord/src/monitor/presence.test.ts
@@ -1,44 +1,61 @@
 import { describe, expect, it } from "vitest";
 import { resolveDiscordPresenceUpdate } from "./presence.js";
 
+type DiscordPresenceUpdate = NonNullable<ReturnType<typeof resolveDiscordPresenceUpdate>>;
+
+function expectPresenceUpdate(
+  result: ReturnType<typeof resolveDiscordPresenceUpdate>,
+): DiscordPresenceUpdate {
+  expect(result).toEqual(expect.objectContaining({ activities: expect.any(Array) }));
+  if (result === null) {
+    throw new Error("Expected Discord presence update");
+  }
+  return result;
+}
+
 describe("resolveDiscordPresenceUpdate", () => {
   it("returns online presence when no config is provided", () => {
-    const result = resolveDiscordPresenceUpdate({});
-    expect(result).not.toBeNull();
-    expect(result!.status).toBe("online");
-    expect(result!.activities).toEqual([]);
+    const result = expectPresenceUpdate(resolveDiscordPresenceUpdate({}));
+    expect(result.status).toBe("online");
+    expect(result.activities).toEqual([]);
   });
 
   it("uses configured status", () => {
-    const result = resolveDiscordPresenceUpdate({ status: "dnd" });
-    expect(result!.status).toBe("dnd");
+    const result = expectPresenceUpdate(resolveDiscordPresenceUpdate({ status: "dnd" }));
+    expect(result.status).toBe("dnd");
   });
 
   it("includes activity when configured", () => {
-    const result = resolveDiscordPresenceUpdate({ activity: "Helping humans" });
-    expect(result!.status).toBe("online");
-    expect(result!.activities).toHaveLength(1);
-    expect(result!.activities[0].state).toBe("Helping humans");
+    const result = expectPresenceUpdate(
+      resolveDiscordPresenceUpdate({ activity: "Helping humans" }),
+    );
+    expect(result.status).toBe("online");
+    expect(result.activities).toHaveLength(1);
+    expect(result.activities[0].state).toBe("Helping humans");
   });
 
   it("uses custom activity type by default", () => {
-    const result = resolveDiscordPresenceUpdate({ activity: "test" });
-    expect(result!.activities[0].type).toBe(4);
-    expect(result!.activities[0].name).toBe("Custom Status");
+    const result = expectPresenceUpdate(resolveDiscordPresenceUpdate({ activity: "test" }));
+    expect(result.activities[0].type).toBe(4);
+    expect(result.activities[0].name).toBe("Custom Status");
   });
 
   it("respects explicit activityType", () => {
-    const result = resolveDiscordPresenceUpdate({ activity: "test", activityType: 3 });
-    expect(result!.activities[0].type).toBe(3);
-    expect(result!.activities[0].name).toBe("test");
+    const result = expectPresenceUpdate(
+      resolveDiscordPresenceUpdate({ activity: "test", activityType: 3 }),
+    );
+    expect(result.activities[0].type).toBe(3);
+    expect(result.activities[0].name).toBe("test");
   });
 
   it("sets streaming URL for type 1", () => {
-    const result = resolveDiscordPresenceUpdate({
-      activity: "Live",
-      activityType: 1,
-      activityUrl: "https://twitch.tv/test",
-    });
-    expect(result!.activities[0].url).toBe("https://twitch.tv/test");
+    const result = expectPresenceUpdate(
+      resolveDiscordPresenceUpdate({
+        activity: "Live",
+        activityType: 1,
+        activityUrl: "https://twitch.tv/test",
+      }),
+    );
+    expect(result.activities[0].url).toBe("https://twitch.tv/test");
   });
 });
diff --git a/extensions/memory-wiki/src/tool.test.ts b/extensions/memory-wiki/src/tool.test.ts
index 9fd0acf780e..5c0888862b0 100644
--- a/extensions/memory-wiki/src/tool.test.ts
+++ b/extensions/memory-wiki/src/tool.test.ts
@@ -3,9 +3,11 @@ import type { ResolvedMemoryWikiConfig } from "./config.js";
 import { createWikiApplyTool } from "./tool.js";
 
 function asSchemaObject(value: unknown): Record<string, unknown> {
-  expect(typeof value).toBe("object");
-  expect(value).not.toBeNull();
+  expect(value).toEqual(expect.any(Object));
   expect(Array.isArray(value)).toBe(false);
+  if (typeof value !== "object" || value === null || Array.isArray(value)) {
+    throw new Error("Expected JSON schema object");
+  }
   return value as Record<string, unknown>;
 }