fix: do not modify constructor options (#974)

AVaksman · stephenplusplus · commit 4969148f5e11 · 2020-01-07T08:31:44.000-05:00
diff --git a/src/storage.ts b/src/storage.ts
@@ -372,12 +372,14 @@ export class Storage extends Service {
    * @param {StorageOptions} [options] Configuration options.
    */
   constructor(options: StorageOptions = {}) {
-    options.apiEndpoint = options.apiEndpoint || 'storage.googleapis.com';
+    options = Object.assign({}, options, {
+      apiEndpoint: options.apiEndpoint || 'storage.googleapis.com',
+    });
     const url =
       process.env.STORAGE_EMULATOR_HOST ||
       `https://${options.apiEndpoint}/storage/v1`;
     const config = {
-      apiEndpoint: options.apiEndpoint,
+      apiEndpoint: options.apiEndpoint!,
       baseUrl: url,
       projectIdRequired: false,
       scopes: [
diff --git a/test/index.ts b/test/index.ts
@@ -141,6 +141,20 @@ describe('Storage', () => {
       );
     });
 
+    it('should not modify options argument', () => {
+      const options = {
+        projectId: PROJECT_ID,
+      };
+      const expectedCalledWith = Object.assign({}, options, {
+        apiEndpoint: 'storage.googleapis.com',
+      });
+      storage = new Storage(options);
+      const calledWith = storage.calledWith_[1];
+      assert.notStrictEqual(calledWith, options);
+      assert.notDeepStrictEqual(calledWith, options);
+      assert.deepStrictEqual(calledWith, expectedCalledWith);
+    });
+
     it('should propagate the apiEndpoint option', () => {
       const apiEndpoint = 'some.fake.endpoint';
       storage = new Storage({
