feat(callApi): create callApi helper to call ky callbacks and use Go-like pattern to return [data, error] tuple

src/shared/utils/helpers/callApi/callApi.spec.ts

@@ -0,0 +1,40 @@
+import { HTTPError } from "ky";
+import { callApi } from "./callApi";
+
+function makeHttpError(status: number, body: object) {
+  const response = new Response(JSON.stringify(body), {
+    status,
+    headers: { "Content-Type": "application/json" },
+  });
+  return new HTTPError(response, new Request("http://test.com"), {});
+}
+
+describe("callApi", () => {
+  describe("happy path", () => {
+    it("returns [data, null] when the fn resolves", async () => {
+      const [data, error] = await callApi(() => Promise.resolve({ id: 1 }));
+
+      expect(data).toEqual({ id: 1 });
+      expect(error).toBeNull();
+    });
+  });
+
+  describe("error cases", () => {
+    it("returns [null, ApiError] on HTTPError", async () => {
+      const [data, error] = await callApi(() =>
+        Promise.reject(makeHttpError(401, { message: "Unauthorized" })),
+      );
+
+      expect(data).toBeNull();
+      expect(error).toEqual({ status: 401, message: "Unauthorized" });
+    });
+
+    it("re-throws non-HTTP errors", async () => {
+      const unexpected = new TypeError("Network failure");
+
+      await expect(
+        callApi(() => Promise.reject(unexpected)),
+      ).rejects.toThrow("Network failure");
+    });
+  });
+});