datastore: recognize DATASTORE_DATASET env var

lib/datastore/dataset.js

@@ -68,6 +68,9 @@ var SCOPES = [
  * Interact with a dataset from the
  * [Google Cloud Datastore](https://developers.google.com/datastore/).
  *
+ * If a project ID is not specified, the `DATASTORE_DATASET` environment
+ * variable from the gcloud SDK is used.
+ *
  * @constructor
  * @alias module:datastore/dataset
  * @mixes module:datastore/request
@@ -106,13 +109,14 @@ function Dataset(options) {
 
   options = options || {};
 
-  if (!options.projectId) {
-    throw util.missingProjectIdError;
+  this.datasetId = options.projectId || process.env.DATASTORE_DATASET;
+
+  if (!this.datasetId) {
+    throw new Error('A project or dataset ID is required to use a Dataset.');
   }
 
   this.determineApiEndpoint_(options.apiEndpoint);
   this.namespace = options.namespace;
-  this.projectId = options.projectId;
 
   this.makeAuthenticatedRequest_ = util.makeAuthenticatedRequestFactory({
     customEndpoint: this.customEndpoint,
@@ -306,7 +310,7 @@ Dataset.prototype.runInTransaction = function(fn, callback) {
  * @private
  */
 Dataset.prototype.createTransaction_ = function() {
-  return new Transaction(this, this.projectId);
+  return new Transaction(this, this.datasetId);
 };
 
 module.exports = Dataset;

lib/datastore/request.js

@@ -784,10 +784,10 @@ DatastoreRequest.prototype.makeReq_ = function(method, body, callback) {
 
   var reqOpts = {
     method: 'POST',
-    uri: format('{apiEndpoint}/{path}/{projectId}/{method}', {
+    uri: format('{apiEndpoint}/{path}/{datasetId}/{method}', {
       apiEndpoint: this.apiEndpoint,
       path: 'datastore/v1beta2/datasets',
-      projectId: this.projectId,
+      datasetId: this.datasetId,
       method: method
     }),
     body: is.empty(body) ? '' : pbRequest,

lib/datastore/transaction.js

@@ -41,8 +41,7 @@ var extend = require('extend');
  *
  * @param {module:common/connection#Connection} connection - An authenticated
  *     connection to Google Cloud Datastore.
- * @param {string} projectId - Dataset ID. This is your project ID from the
- *     Google Developers Console.
+ * @param {string} datasetId - Dataset ID.
  *
  * @example
  * // This is how to create a transaction object directly using this Transaction
@@ -69,11 +68,11 @@ var extend = require('extend');
  *   // `transaction` is a Transaction object.
  * }, function(err) {});
  */
-function Transaction(dataset, projectId) {
+function Transaction(dataset, datasetId) {
   this.id = null;
   this.apiEndpoint = dataset.apiEndpoint;
   this.makeAuthenticatedRequest_ = dataset.makeAuthenticatedRequest_;
-  this.projectId = projectId;
+  this.datasetId = datasetId;
 
   // A queue for entity modifications made during the transaction.
   this.modifiedEntities_ = [];

test/datastore/dataset.js

@@ -31,6 +31,10 @@ util.makeAuthenticatedRequestFactory = function() {
   return makeAuthenticatedRequestFactoryCache.apply(this, arguments);
 };
 
+function FakeTransaction() {
+  this.calledWith_ = arguments;
+}
+
 describe('Dataset', function() {
   var Dataset;
   var dataset;
@@ -46,6 +50,7 @@ describe('Dataset', function() {
 
   before(function() {
     mockery.registerMock('../common/util.js', util);
+    mockery.registerMock('./transaction.js', FakeTransaction);
 
     mockery.enable({
       useCleanCache: true,
@@ -61,15 +66,30 @@ describe('Dataset', function() {
   });
 
   beforeEach(function() {
+    delete process.env.DATASTORE_DATASET;
     makeAuthenticatedRequestFactoryOverride = null;
     dataset = new Dataset(OPTIONS);
   });
 
   describe('instantiation', function() {
+    it('should localize the dataset id', function() {
+      assert.strictEqual(dataset.datasetId, OPTIONS.projectId);
+    });
+
+    it('should detect the dataset ID', function() {
+      var datasetId = 'dataset-id';
+      process.env.DATASTORE_DATASET = datasetId;
+
+      var ds = new Dataset();
+      assert.strictEqual(ds.datasetId, datasetId);
+
+      delete process.env.DATASTORE_DATASET;
+    });
+
     it('should throw if a projectId is not specified', function() {
       assert.throws(function() {
         new Dataset();
-      }, /Sorry, we cannot connect/);
+      }, 'A project or dataset ID is required to use a Dataset.');
     });
 
     it('should set default API connection details', function(done) {
@@ -85,6 +105,10 @@ describe('Dataset', function() {
       new Dataset(OPTIONS);
     });
 
+    it('should localize the namespace', function() {
+      assert.strictEqual(dataset.namespace, OPTIONS.namespace);
+    });
+
     it('should create an authenticated request factory', function() {
       var authenticatedRequest = {};
       var customEndpoint = 'custom-endpoint';
@@ -112,14 +136,6 @@ describe('Dataset', function() {
       var ds = new Dataset(OPTIONS);
       assert.strictEqual(ds.makeAuthenticatedRequest_, authenticatedRequest);
     });
-
-    it('should localize the project id', function() {
-      assert.strictEqual(dataset.projectId, OPTIONS.projectId);
-    });
-
-    it('should localize the namespace', function() {
-      assert.strictEqual(dataset.namespace, OPTIONS.namespace);
-    });
   });
 
   describe('key', function() {
@@ -337,4 +353,13 @@ describe('Dataset', function() {
       });
     });
   });
+
+  describe('createTransaction_', function() {
+    it('should create and return a Transaction', function() {
+      var transaction = dataset.createTransaction_();
+      assert(transaction instanceof FakeTransaction);
+      assert.strictEqual(transaction.calledWith_[0], dataset);
+      assert.strictEqual(transaction.calledWith_[1], dataset.datasetId);
+    });
+  });
 });

test/datastore/request.js

@@ -864,15 +864,15 @@ describe('Request', function() {
 
     it('should assemble correct request', function(done) {
       var method = 'commit';
-      var projectId = 'project-id';
+      var datasetId = 'dataset-id';
       var expectedUri =
-        format('{apiEndpoint}/datastore/v1beta2/datasets/{pId}/{method}', {
+        format('{apiEndpoint}/datastore/v1beta2/datasets/{dId}/{method}', {
           apiEndpoint: CUSTOM_ENDPOINT,
-          pId: projectId,
+          dId: datasetId,
           method: method
         });
 
-      request.projectId = projectId;
+      request.datasetId = datasetId;
       request.makeAuthenticatedRequest_ = function(opts) {
         assert.equal(opts.method, 'POST');
         assert.equal(opts.uri, expectedUri);

test/datastore/transaction.js

@@ -79,21 +79,21 @@ describe('Transaction', function() {
 
   describe('instantiation', function() {
     it('should assign default properties', function() {
-      var projectId = 'abc';
+      var datasetId = 'abc';
       var fakeDataset = {
         apiEndpoint: 'http://localhost:8080',
         makeAuthenticatedRequest_: function fakeMakeAuthenticatedRequest_() {}
       };
 
-      var transaction = new Transaction(fakeDataset, projectId);
+      var transaction = new Transaction(fakeDataset, datasetId);
 
       assert.strictEqual(transaction.id, null);
       assert.deepEqual(transaction.apiEndpoint, fakeDataset.apiEndpoint);
       assert.equal(
         transaction.makeAuthenticatedRequest_,
         fakeDataset.makeAuthenticatedRequest_
       );
-      assert.equal(transaction.projectId, projectId);
+      assert.equal(transaction.datasetId, datasetId);
     });
   });