test: tighten runner image helper assertions

src/agents/pi-embedded-helpers.isbillingerrormessage.test.ts

@@ -963,10 +963,11 @@ describe("image dimension errors", () => {
     const raw =
       '400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.84.content.1.image.source.base64.data: At least one of the image dimensions exceed max allowed size for many-image requests: 2000 pixels"}}';
     const parsed = parseImageDimensionError(raw);
-    expect(parsed).not.toBeNull();
-    expect(parsed?.maxDimensionPx).toBe(2000);
-    expect(parsed?.messageIndex).toBe(84);
-    expect(parsed?.contentIndex).toBe(1);
+    expect(parsed).toMatchObject({
+      maxDimensionPx: 2000,
+      messageIndex: 84,
+      contentIndex: 1,
+    });
     expect(isImageDimensionErrorMessage(raw)).toBe(true);
   });
 });

src/agents/pi-embedded-runner/run.incomplete-turn.test.ts

@@ -1072,8 +1072,7 @@ describe("runEmbeddedPiAgent incomplete-turn safety", () => {
       }),
     });
 
-    expect(incompleteTurnText).not.toBeNull();
-    expect(incompleteTurnText).toContain("couldn't generate a response");
+    expect(incompleteTurnText).toEqual(expect.stringContaining("couldn't generate a response"));
   });
 
   it("surfaces tool-use terminal with pre-tool text and side effects as replay-unsafe (#76477)", () => {

src/agents/pi-embedded-runner/run/images.test.ts

@@ -267,8 +267,7 @@ describe("loadImageFromRef", () => {
         },
       );
 
-      expect(image).not.toBeNull();
-      expect(image?.type).toBe("image");
+      expect(image).toMatchObject({ type: "image" });
       expect(image?.data.length).toBeGreaterThan(0);
     } finally {
       await fs.rm(sandboxParent, { recursive: true, force: true });