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");
+    });
+  });
+});

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

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+import { HTTPError } from "ky";
+
+export interface ApiError {
+  /**
+   * Client error response status code
+   */
+  status: number;
+  /**
+   * Error message
+   */
+  message: string;
+}
+
+/**
+ * Helper function that calls Ky and manages its errors;
+ * @returns A tuple [data, error] in Golang-like fashion
+ */
+export async function callApi<T>(
+  fn: () => Promise<T>,
+): Promise<[T, null] | [null, ApiError]> {
+  try {
+    const data = await fn();
+    return [data, null];
+  } catch (error) {
+    if (error instanceof HTTPError) {
+      const body = await error.response.json<{ message: string }>();
+      return [null, { status: error.response.status, message: body.message }];
+    }
+
+    // re-throw unexpected errors
+    throw error;
+  }
+}

src/shared/utils/helpers/index.ts

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+export * from "./callApi/callApi";

src/shared/utils/index.ts

@@ -0,0 +1 @@
+export * from "./helpers";