Route /auth and /config to local API; everything else uses API_URL

src/lib/__tests__/api-url.test.ts

@@ -11,19 +11,19 @@ test('uses basePath with the default api path', () => {
   );
 });
 
-test('uses a relative API_URL', () => {
+test('routes calls through a relative API_URL', () => {
   expect(getApiUrl('/websites', { apiUrl: '/backend/api', basePath: '' })).toBe(
     '/backend/api/websites',
   );
 });
 
-test('uses basePath with a relative API_URL', () => {
+test('routes calls through basePath with a relative API_URL', () => {
   expect(getApiUrl('/websites', { apiUrl: '/backend/api', basePath: '/analytics' })).toBe(
     '/analytics/backend/api/websites',
   );
 });
 
-test('uses an absolute API_URL directly', () => {
+test('routes calls through an absolute API_URL', () => {
   expect(getApiUrl('/websites', { apiUrl: 'https://api.example.com/api', basePath: '' })).toBe(
     'https://api.example.com/api/websites',
   );
@@ -34,3 +34,24 @@ test('leaves absolute request URLs unchanged', () => {
     'https://example.com/custom',
   );
 });
+
+test('keeps /auth/* on the default api path', () => {
+  expect(
+    getApiUrl('/auth/login', { apiUrl: 'https://api.example.com/api', basePath: '' }),
+  ).toBe('/api/auth/login');
+});
+
+test('keeps /config on the default api path', () => {
+  expect(getApiUrl('/config', { apiUrl: 'https://api.example.com/api', basePath: '' })).toBe(
+    '/api/config',
+  );
+});
+
+test('keeps /auth/* on the default api path with basePath', () => {
+  expect(
+    getApiUrl('/auth/verify', {
+      apiUrl: 'https://api.example.com/api',
+      basePath: '/analytics',
+    }),
+  ).toBe('/analytics/api/auth/verify');
+});

src/lib/api-url.ts

@@ -3,6 +3,11 @@ type ApiUrlOptions = {
   basePath?: string;
 };
 
+const APP_ROUTE_PATTERNS: RegExp[] = [
+  /^\/auth(\/|$)/,
+  /^\/config(\/|$)/,
+];
+
 function trimTrailingSlash(value: string) {
   return value.replace(/\/+$/, '');
 }
@@ -23,13 +28,19 @@ function isAbsoluteUrl(url: string) {
   return /^https?:\/\//i.test(url);
 }
 
+function isAppRoute(url: string) {
+  const path = `/${trimLeadingSlash(url.split('?')[0])}`;
+  return APP_ROUTE_PATTERNS.some(re => re.test(path));
+}
+
 export function getApiUrl(url: string, options: ApiUrlOptions = {}) {
   if (isAbsoluteUrl(url)) {
     return url;
   }
 
   const { apiUrl = process.env.apiUrl || '', basePath = process.env.basePath || '' } = options;
-  const baseUrl = apiUrl
+  const useApiUrl = apiUrl && !isAppRoute(url);
+  const baseUrl = useApiUrl
     ? isAbsoluteUrl(apiUrl)
       ? apiUrl
       : joinPath(basePath, apiUrl)