From ceabae9dedddffd10414216be5913dd011ecb780 Mon Sep 17 00:00:00 2001
From: Ru Chern Chong <ruchern.chong@sgcarstrends.com>
Date: Wed, 16 Oct 2024 22:47:23 +0800
Subject: [PATCH] Add error handling for fetchApi helper

---
 utils/fetchApi.test.ts | 55 +++++++++++++++++++++++++++++++++++++++---
 utils/fetchApi.ts      | 32 +++++++++++++++++-------
 2 files changed, 75 insertions(+), 12 deletions(-)

diff --git a/utils/fetchApi.test.ts b/utils/fetchApi.test.ts
index 2ca3eb6..c24e4ba 100644
--- a/utils/fetchApi.test.ts
+++ b/utils/fetchApi.test.ts
@@ -2,15 +2,64 @@ import fetch from "jest-fetch-mock";
 import { fetchApi } from "@/utils/fetchApi";
 
 describe("fetchApi", () => {
-  beforeEach(() => fetch.resetMocks());
+  beforeEach(() => {
+    fetch.resetMocks();
+  });
 
   it("should return data for a successful API call", async () => {
-    fetch.mockResponseOnce(JSON.stringify({ data: "test" }));
+    const mockResponse = { data: "test" };
+    fetch.mockResponseOnce(JSON.stringify(mockResponse));
 
     const url = "https://example.com/api/test";
     const data = await fetchApi(url);
 
     expect(fetch).toHaveBeenCalledTimes(1);
-    expect(data).toEqual({ data: "test" });
+    expect(fetch).toHaveBeenCalledWith(url, {
+      cache: "no-store",
+      headers: {
+        Authorization: `Bearer ${process.env.SG_CARS_TRENDS_API_TOKEN}`,
+      },
+    });
+    expect(data).toEqual(mockResponse);
+  });
+
+  it("should throw an error for a non-OK response", async () => {
+    const errorBody = "Error occurred";
+    fetch.mockResponseOnce(errorBody, { status: 404, statusText: "Not Found" });
+
+    const url = "https://example.com/api/test";
+    await expect(fetchApi(url)).rejects.toThrow(
+      `API call failed: ${url} - 404 - Not Found`,
+    );
+  });
+
+  it("should merge custom options with default options", async () => {
+    fetch.mockResponseOnce(JSON.stringify({ data: "test" }));
+
+    const url = "https://example.com/api/test";
+    const customOptions = {
+      method: "POST",
+      headers: {
+        "Custom-Header": "CustomValue",
+      },
+    };
+
+    await fetchApi(url, customOptions);
+
+    expect(fetch).toHaveBeenCalledWith(url, {
+      method: "POST",
+      cache: "no-store",
+      headers: {
+        Authorization: `Bearer ${process.env.SG_CARS_TRENDS_API_TOKEN}`,
+        "Custom-Header": "CustomValue",
+      },
+    });
+  });
+
+  it("should handle network errors", async () => {
+    fetch.mockReject(new Error("Network error"));
+
+    const url = "https://example.com/api/test";
+    await expect(fetchApi(url)).rejects.toThrow("Network error");
   });
 });
diff --git a/utils/fetchApi.ts b/utils/fetchApi.ts
index 8e3e2c1..03c4e2e 100644
--- a/utils/fetchApi.ts
+++ b/utils/fetchApi.ts
@@ -2,21 +2,35 @@ export const fetchApi = async <T>(
   url: string,
   options: RequestInit = {},
 ): Promise<T> => {
-  options = {
-    ...options,
+  const defaultOptions: RequestInit = {
     // TODO: Remove this later
     cache: "no-store",
     headers: {
       Authorization: `Bearer ${process.env.SG_CARS_TRENDS_API_TOKEN}`,
     },
   };
-  const response = await fetch(url, options);
 
-  if (!response.ok) {
-    throw new Error(
-      `API call failed: ${url} - ${response.status} - ${response.statusText}`,
-    );
-  }
+  const mergedOptions: RequestInit = {
+    ...defaultOptions,
+    ...options,
+    headers: {
+      ...defaultOptions.headers,
+      ...options.headers,
+    },
+  };
+
+  try {
+    const response = await fetch(url, mergedOptions);
 
-  return response.json();
+    if (!response.ok) {
+      throw new Error(
+        `API call failed: ${url} - ${response.status} - ${response.statusText}`,
+      );
+    }
+
+    return response.json();
+  } catch (e) {
+    console.error(e.message);
+    throw e;
+  }
 };