feat: support apiEndpoint override

package.json

@@ -50,10 +50,9 @@
     "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",
-    "@types/protobufjs": "^6.0.0",
     "arrify": "^2.0.0",
     "compressible": "^2.0.12",
     "concat-stream": "^2.0.0",

src/storage.ts

@@ -50,6 +50,11 @@ export interface StorageOptions extends GoogleAuthOptions {
   autoRetry?: boolean;
   maxRetries?: number;
   promise?: typeof Promise;
+  /**
+   * The API endpoint of the service used to make requests.
+   * Defaults to `www.googleapis.com`.
+   */
+  apiEndpoint?: string;
 }
 
 export interface BucketOptions {
@@ -285,8 +290,10 @@ export class Storage extends Service {
    * @param {StorageOptions} [options] Configuration options.
    */
   constructor(options: StorageOptions = {}) {
+    options.apiEndpoint = options.apiEndpoint || 'www.googleapis.com';
     const config = {
-      baseUrl: 'https://www.googleapis.com/storage/v1',
+      apiEndpoint: options.apiEndpoint,
+      baseUrl: `https://${options.apiEndpoint}/storage/v1`,
       projectIdRequired: false,
       scopes: [
         'https://www.googleapis.com/auth/iam',

test/index.ts

@@ -134,6 +134,20 @@ describe('Storage', () => {
         require('../../package.json')
       );
     });
+
+    it('should propagate the apiEndpoint option', () => {
+      const apiEndpoint = 'some.fake.endpoint';
+      storage = new Storage({
+        projectId: PROJECT_ID,
+        apiEndpoint,
+      });
+      const calledWith = storage.calledWith_[0];
+      assert.strictEqual(
+        calledWith.baseUrl,
+        `https://${apiEndpoint}/storage/v1`
+      );
+      assert.strictEqual(calledWith.apiEndpoint, apiEndpoint);
+    });
   });
 
   describe('bucket', () => {