feat: support apiEndpoint overrides

package.json

@@ -42,7 +42,7 @@
     "predocs-test": "npm run docs"
   },
   "dependencies": {
-    "@google-cloud/common": "^1.0.0",
+    "@google-cloud/common": "^2.0.0",
     "@google-cloud/paginator": "^1.0.0",
     "@google-cloud/promisify": "^1.0.0",
     "arrify": "^2.0.0",

src/index.ts

@@ -59,6 +59,14 @@ export interface CreateZoneRequest {
 
 export type CreateZoneResponse = [Zone, Metadata];
 
+export interface DNSOptions extends GoogleAuthOptions {
+  /**
+   * The API endpoint of the service used to make requests.
+   * Defaults to `www.googleapis.com`.
+   */
+  apiEndpoint?: string;
+}
+
 /**
  * @typedef {object} ClientConfig
  * @property {string} [projectId] The project ID from the Google Developer's
@@ -118,10 +126,11 @@ export type CreateZoneResponse = [Zone, Metadata];
  */
 class DNS extends Service {
   getZonesStream: (query: GetZonesRequest) => Stream;
-  constructor(options?: GoogleAuthOptions) {
-    options = options || {};
+  constructor(options: DNSOptions = {}) {
+    options.apiEndpoint = options.apiEndpoint || 'www.googleapis.com';
     const config = {
-      baseUrl: 'https://www.googleapis.com/dns/v1',
+      apiEndpoint: options.apiEndpoint,
+      baseUrl: `https://${options.apiEndpoint}/dns/v1`,
       scopes: [
         'https://www.googleapis.com/auth/ndev.clouddns.readwrite',
         'https://www.googleapis.com/auth/cloud-platform',

test/index.ts

@@ -135,6 +135,17 @@ describe('DNS', () => {
         require('../../package.json')
       );
     });
+
+    it('should enable apiEndpoint override', () => {
+      const apiEndpoint = 'fake.endpoint';
+      dns = new DNS({
+        projectId: PROJECT_ID,
+        apiEndpoint,
+      });
+      const calledWith = dns.calledWith_[0];
+      assert.strictEqual(calledWith.apiEndpoint, apiEndpoint);
+      assert.strictEqual(calledWith.baseUrl, `https://${apiEndpoint}/dns/v1`);
+    });
   });
 
   describe('createZone', () => {