Add some simple tests for joinUrls behavior

src/fetchBaseQuery.ts

@@ -32,7 +32,9 @@ export function fetchBaseQuery({ baseUrl }: { baseUrl?: string } = {}) {
  body,
  ...rest,
  };
+
  config.headers = new Headers(headers);
+
  if (!config.headers.has('content-type')) {
  config.headers.set('content-type', 'application/json');
  }
@@ -42,10 +44,12 @@ export function fetchBaseQuery({ baseUrl }: { baseUrl?: string } = {}) {
  }
 
  url = joinUrls(baseUrl, url);
+
  if (params) {
  const searchParams = new URLSearchParams(params);
  url += `?${searchParams.toString()}`;
  }
+
  const response = await fetch(url, config);
 
  let resultData;

src/utils/joinsUrls.test.ts

@@ -0,0 +1,28 @@
+import { joinUrls } from './joinUrls';
+
+test('correctly joins variations relative urls', () => {
+ expect(joinUrls('/api/', '/banana')).toBe('/api/banana');
+ expect(joinUrls('/api', '/banana')).toBe('/api/banana');
+
+ expect(joinUrls('/api/', 'banana')).toBe('/api/banana');
+ expect(joinUrls('/api/', '/banana/')).toBe('/api/banana/');
+
+ expect(joinUrls('/', '/banana/')).toBe('/banana/');
+ expect(joinUrls('/', 'banana/')).toBe('/banana/');
+
+ expect(joinUrls('/', '/banana')).toBe('/banana');
+ expect(joinUrls('/', 'banana')).toBe('/banana');
+
+ expect(joinUrls('', '/banana')).toBe('/banana');
+ expect(joinUrls('', 'banana')).toBe('banana');
+});
+
+test('correctly joins variations of absolute urls', () => {
+ expect(joinUrls('https://apple.com', '/api/banana/')).toBe('https://apple.com/api/banana/');
+ expect(joinUrls('https://apple.com', '/api/banana')).toBe('https://apple.com/api/banana');
+
+ expect(joinUrls('https://apple.com/', 'api/banana/')).toBe('https://apple.com/api/banana/');
+ expect(joinUrls('https://apple.com/', 'api/banana')).toBe('https://apple.com/api/banana');
+
+ expect(joinUrls('https://apple.com/', 'api/banana/')).toBe('https://apple.com/api/banana/');
+});