Initial commit

packages/core-analytics/src/with-analytics.test.ts

@@ -0,0 +1,55 @@
+import { describe, it, expect, expectTypeOf } from "vitest";
+import { withAnalytics, type Analyzed } from "@/with-analytics";
+import type { IAnalytics } from "@/analytics.interface";
+import { isAnalyzed } from "@repo/core-shared/conformance";
+
+function makeAnalytics(): IAnalytics {
+  return {
+    track: () => undefined,
+    identify: () => undefined,
+    pageView: () => undefined,
+    flush: () => Promise.resolve(),
+  };
+}
+
+describe("withAnalytics", () => {
+  it("returns an Analyzed<F>", () => {
+    const analytics = makeAnalytics();
+    const fn = async (_input: { id: string }) => ({ ok: true });
+    const wrapped = withAnalytics(analytics, fn);
+    expectTypeOf(wrapped).toMatchTypeOf<Analyzed<typeof fn>>();
+  });
+
+  it("attaches __analyzed as a non-enumerable property on the wrapped function", () => {
+    const analytics = makeAnalytics();
+    const fn = async () => ({ ok: true });
+    const wrapped = withAnalytics(analytics, fn);
+    expect(isAnalyzed(wrapped)).toBe(true);
+    expect(Object.keys(wrapped)).not.toContain("__analyzed");
+  });
+
+  it("does NOT pollute the original input function with the brand", () => {
+    const analytics = makeAnalytics();
+    const fn = async () => ({ ok: true });
+    const wrapped = withAnalytics(analytics, fn);
+    expect(isAnalyzed(fn)).toBe(false);
+    expect(wrapped).not.toBe(fn);
+  });
+
+  it("passes input and output through unchanged", async () => {
+    const analytics = makeAnalytics();
+    const fn = async (input: { id: string }) => ({ ok: true, id: input.id });
+    const wrapped = withAnalytics(analytics, fn);
+    const result = await wrapped({ id: "abc" });
+    expect(result).toEqual({ ok: true, id: "abc" });
+  });
+
+  it("propagates errors", async () => {
+    const analytics = makeAnalytics();
+    const err = new Error("boom");
+    const wrapped = withAnalytics(analytics, async () => {
+      throw err;
+    });
+    await expect(wrapped()).rejects.toBe(err);
+  });
+});