translate: support GOOGLE_CLOUD_TRANSLATE_ENDPOINT env var (#1674)

Author: stephenplusplus

packages/translate/src/index.js

@@ -53,6 +53,14 @@ var PKG = require('../package.json');
  *
  * @param {object} options - [Configuration object](#/docs).
  * @param {string} options.key - An API key.
+ *
+ * @example
+ * //-
+ * // <h3>Custom Translate API</h3>
+ * //
+ * // The environment variable, `GOOGLE_CLOUD_TRANSLATE_ENDPOINT`, is honored as
+ * // a custom backend which our library will send requests to.
+ * //-
  */
 function Translate(options) {
   if (!(this instanceof Translate)) {
@@ -66,6 +74,13 @@ function Translate(options) {
     throw new Error('An API key is required to use the Translate API.');
   }
 
+  this.baseUrl = 'https://www.googleapis.com/language/translate/v2';
+
+  if (process.env.GOOGLE_CLOUD_TRANSLATE_ENDPOINT) {
+    this.baseUrl = process.env.GOOGLE_CLOUD_TRANSLATE_ENDPOINT
+      .replace(/\/+$/, '');
+  }
+
   this.options = options;
   this.key = options.key;
 }
@@ -382,9 +397,7 @@ Translate.prototype.translate = function(input, options, callback) {
  * @param {function} callback - The callback function passed to `request`.
  */
 Translate.prototype.request = function(reqOpts, callback) {
-  var BASE_URL = 'https://www.googleapis.com/language/translate/v2';
-
-  reqOpts.uri = BASE_URL + reqOpts.uri;
+  reqOpts.uri = this.baseUrl + reqOpts.uri;
 
   reqOpts = extend(true, {}, reqOpts, {
     qs: {

packages/translate/test/index.js

@@ -33,7 +33,9 @@ var fakeUtil = extend({}, util, {
 });
 
 describe('Translate', function() {
-  var API_KEY = 'api-key';
+  var OPTIONS = {
+    key: 'api-key'
+  };
 
   var Translate;
   var translate;
@@ -49,16 +51,14 @@ describe('Translate', function() {
   beforeEach(function() {
     makeRequestOverride = null;
 
-    translate = new Translate({
-      key: API_KEY
-    });
+    translate = new Translate(OPTIONS);
   });
 
   describe('instantiation', function() {
     it('should normalize the arguments', function() {
       var normalizeArguments = fakeUtil.normalizeArguments;
       var normalizeArgumentsCalled = false;
-      var fakeOptions = { key: API_KEY };
+      var fakeOptions = extend({}, OPTIONS);
       var fakeContext = {};
 
       fakeUtil.normalizeArguments = function(context, options, cfg) {
@@ -81,14 +81,48 @@ describe('Translate', function() {
       }, /An API key is required to use the Translate API\./);
     });
 
+    it('should default baseUrl correctly', function() {
+      assert.strictEqual(
+        translate.baseUrl,
+        'https://www.googleapis.com/language/translate/v2'
+      );
+    });
+
     it('should localize the options', function() {
-      var options = { key: API_KEY };
+      var options = { key: '...' };
       var translate = new Translate(options);
       assert.strictEqual(translate.options, options);
     });
 
     it('should localize the api key', function() {
-      assert.equal(translate.key, API_KEY);
+      assert.equal(translate.key, OPTIONS.key);
+    });
+
+    describe('GOOGLE_CLOUD_TRANSLATE_ENDPOINT', function() {
+      var CUSTOM_ENDPOINT = '...';
+      var translate;
+
+      before(function() {
+        process.env.GOOGLE_CLOUD_TRANSLATE_ENDPOINT = CUSTOM_ENDPOINT;
+        translate = new Translate(OPTIONS);
+      });
+
+      after(function() {
+        delete process.env.GOOGLE_CLOUD_TRANSLATE_ENDPOINT;
+      });
+
+      it('should correctly set the baseUrl', function() {
+        assert.strictEqual(translate.baseUrl, CUSTOM_ENDPOINT);
+      });
+
+      it('should remove trailing slashes', function() {
+        var expectedBaseUrl = 'http://localhost:8080';
+
+        process.env.GOOGLE_CLOUD_TRANSLATE_ENDPOINT = 'http://localhost:8080//';
+
+        var translate = new Translate(OPTIONS);
+        assert.strictEqual(translate.baseUrl, expectedBaseUrl);
+      });
     });
   });
 
@@ -446,8 +480,8 @@ describe('Translate', function() {
           'User-Agent': userAgent
         }
       });
-      var BASE_URL = 'https://www.googleapis.com/language/translate/v2';
-      expectedReqOpts.uri = BASE_URL + reqOpts.uri;
+
+      expectedReqOpts.uri = translate.baseUrl + reqOpts.uri;
 
       makeRequestOverride = function(reqOpts, options, callback) {
         assert.deepEqual(reqOpts, expectedReqOpts);