feat(core-testing): RecordingTracer for span assertions

packages/core-testing/src/instrumentation/recording-tracer.test.ts

@@ -0,0 +1,70 @@
+import { describe, it, expect } from "vitest";
+import { RecordingTracer } from "@/instrumentation/recording-tracer";
+
+describe("RecordingTracer", () => {
+  it("records every startSpan call with name, op, attributes, status, durationMs", async () => {
+    const tracer = new RecordingTracer();
+    await tracer.startSpan(
+      { name: "blog.getArticles", op: "use-case", attributes: { limit: 10 } },
+      async (span) => {
+        span.setAttribute("count", 3);
+        span.setStatus("ok");
+        return undefined;
+      },
+    );
+    expect(tracer.spans).toHaveLength(1);
+    const s = tracer.spans[0]!;
+    expect(s.name).toBe("blog.getArticles");
+    expect(s.op).toBe("use-case");
+    expect(s.attributes).toMatchObject({ limit: 10, count: 3 });
+    expect(s.status).toBe("ok");
+    expect(typeof s.durationMs).toBe("number");
+    expect(s.durationMs).toBeGreaterThanOrEqual(0);
+  });
+
+  it("records error status when fn throws", async () => {
+    const tracer = new RecordingTracer();
+    await expect(
+      tracer.startSpan({ name: "x" }, async () => {
+        throw new Error("boom");
+      }),
+    ).rejects.toThrow("boom");
+    expect(tracer.spans).toHaveLength(1);
+    expect(tracer.spans[0]!.status).toBe("error");
+    expect(tracer.spans[0]!.statusMessage).toBe("boom");
+  });
+
+  it("records error status when set explicitly via span.setStatus", async () => {
+    const tracer = new RecordingTracer();
+    await tracer.startSpan({ name: "x" }, async (span) => {
+      span.setStatus("error", "validation failed");
+      return undefined;
+    });
+    expect(tracer.spans[0]!.status).toBe("error");
+    expect(tracer.spans[0]!.statusMessage).toBe("validation failed");
+  });
+
+  it("reset() clears recorded spans", async () => {
+    const tracer = new RecordingTracer();
+    await tracer.startSpan({ name: "x" }, async () => undefined);
+    expect(tracer.spans).toHaveLength(1);
+    tracer.reset();
+    expect(tracer.spans).toHaveLength(0);
+  });
+
+  it("findSpan returns first matching span by name", async () => {
+    const tracer = new RecordingTracer();
+    await tracer.startSpan({ name: "a" }, async () => undefined);
+    await tracer.startSpan({ name: "b" }, async () => undefined);
+    expect(tracer.findSpan("b")).toBeDefined();
+    expect(tracer.findSpan("missing")).toBeUndefined();
+  });
+
+  it("nested spans are recorded in order (children appear after parent end)", async () => {
+    const tracer = new RecordingTracer();
+    await tracer.startSpan({ name: "parent" }, async () => {
+      await tracer.startSpan({ name: "child" }, async () => undefined);
+    });
+    expect(tracer.spans.map((s) => s.name)).toEqual(["child", "parent"]);
+  });
+});