From 2c7ddd871a6633bb73289c95003c2278ef74a2ac Mon Sep 17 00:00:00 2001
From: Mike Moore <mike@blowmage.com>
Date: Tue, 2 Aug 2016 13:04:38 -0600
Subject: [PATCH] Add coverage to service factory methods

Rename Backoff to GrpcBackoff, since this is now private.
Fix calls to Core::GCE.
---
 .../test/google/cloud/bigquery_test.rb        | 133 +++++++++++------
 .../lib/google/cloud/core/backoff.rb          |  77 ++--------
 .../lib/google/cloud/core/grpc_backoff.rb     |  89 ++++++++++++
 .../lib/google/cloud/datastore/dataset.rb     |   2 +-
 .../lib/google/cloud/datastore/service.rb     |   4 +-
 .../test/google/cloud/datastore_test.rb       | 133 +++++++++++------
 .../lib/google/cloud/dns/project.rb           |   2 +-
 .../test/google/cloud/dns_test.rb             | 133 +++++++++++------
 .../lib/google/cloud/logging/project.rb       |   2 +-
 .../lib/google/cloud/logging/service.rb       |   4 +-
 .../test/google/cloud/logging/backoff_test.rb |   4 +-
 .../test/google/cloud/logging_test.rb         | 133 +++++++++++------
 .../lib/google/cloud/pubsub/project.rb        |   2 +-
 .../lib/google/cloud/pubsub/service.rb        |   4 +-
 .../test/google/cloud/pubsub/backoff_test.rb  |   4 +-
 .../test/google/cloud/pubsub_test.rb          | 133 +++++++++++------
 .../google/cloud/resource_manager_test.rb     | 124 +++++++++++-----
 .../lib/google/cloud/storage/project.rb       |   2 +-
 .../lib/google/cloud/storage/service.rb       |   2 +-
 .../test/google/cloud/storage_test.rb         | 135 ++++++++++++------
 .../test/google/cloud/translate_test.rb       | 114 ++++++++++-----
 .../lib/google/cloud/vision/project.rb        |   2 +-
 .../test/google/cloud/vision_test.rb          | 134 +++++++++++------
 23 files changed, 934 insertions(+), 438 deletions(-)
 create mode 100644 google-cloud-core/lib/google/cloud/core/grpc_backoff.rb

diff --git a/google-cloud-bigquery/test/google/cloud/bigquery_test.rb b/google-cloud-bigquery/test/google/cloud/bigquery_test.rb
index 79ca6a8ca96a..08df281d5a59 100644
--- a/google-cloud-bigquery/test/google/cloud/bigquery_test.rb
+++ b/google-cloud-bigquery/test/google/cloud/bigquery_test.rb
@@ -16,51 +16,104 @@
 require "google/cloud/bigquery"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.bigquery" do
-    gcloud = Google::Cloud.new
-    stubbed_bigquery = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "bigquery-project-object-empty"
-    }
-    Google::Cloud.stub :bigquery, stubbed_bigquery do
-      project = gcloud.bigquery
-      project.must_equal "bigquery-project-object-empty"
+  describe "#bigquery" do
+    it "calls out to Google::Cloud.bigquery" do
+      gcloud = Google::Cloud.new
+      stubbed_bigquery = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "bigquery-project-object-empty"
+      }
+      Google::Cloud.stub :bigquery, stubbed_bigquery do
+        project = gcloud.bigquery
+        project.must_equal "bigquery-project-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.bigquery" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_bigquery = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "bigquery-project-object"
+      }
+      Google::Cloud.stub :bigquery, stubbed_bigquery do
+        project = gcloud.bigquery
+        project.must_equal "bigquery-project-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.bigquery" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_bigquery = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "bigquery-project-object"
-    }
-    Google::Cloud.stub :bigquery, stubbed_bigquery do
-      project = gcloud.bigquery
-      project.must_equal "bigquery-project-object"
+    it "passes project and keyfile and options to Google::Cloud.bigquery" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_bigquery = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "bigquery-project-object-scoped"
+      }
+      Google::Cloud.stub :bigquery, stubbed_bigquery do
+        project = gcloud.bigquery scope: "http://example.com/scope", retries: 5, timeout: 60
+        project.must_equal "bigquery-project-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.bigquery" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_bigquery = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "bigquery-project-object-scoped"
-    }
-    Google::Cloud.stub :bigquery, stubbed_bigquery do
-      project = gcloud.bigquery scope: "http://example.com/scope", retries: 5, timeout: 60
-      project.must_equal "bigquery-project-object-scoped"
+  describe ".bigquery" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Bigquery::Credentials.stub :default, default_credentials do
+            bigquery = Google::Cloud.bigquery
+            bigquery.must_be_kind_of Google::Cloud::Bigquery::Project
+            bigquery.project.must_equal "project-id"
+            bigquery.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "bigquery-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "bigquery-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Bigquery::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Bigquery::Service.stub :new, stubbed_service do
+                bigquery = Google::Cloud.bigquery "project-id", "path/to/keyfile.json"
+                bigquery.must_be_kind_of Google::Cloud::Bigquery::Project
+                bigquery.project.must_equal "project-id"
+                bigquery.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-core/lib/google/cloud/core/backoff.rb b/google-cloud-core/lib/google/cloud/core/backoff.rb
index 6441cf9ecb0d..bf10c94090c3 100644
--- a/google-cloud-core/lib/google/cloud/core/backoff.rb
+++ b/google-cloud-core/lib/google/cloud/core/backoff.rb
@@ -25,7 +25,7 @@ module Core
       # increasing delay will be added between each retried call. The first
       # retry will be delayed one second, the second retry will be delayed
       # two seconds, and so on.
-      class Backoff
+      class GrpcBackoff
         class << self
           ##
           # The number of times a retriable API call should be retried.
@@ -42,19 +42,6 @@ def retries= new_retries
           # The default values are `14`.
           attr_accessor :grpc_codes
 
-          ##
-          # The HTTP Status Codes that should be retried.
-          #
-          # The default values are `500` and `503`.
-          attr_accessor :http_codes
-
-          ##
-          # The Google API error reasons that should be retried.
-          #
-          # The default values are `rateLimitExceeded` and
-          # `userRateLimitExceeded`.
-          attr_accessor :reasons
-
           ##
           # The code to run when a backoff is handled.
           # This must be a Proc and must take the number of
@@ -66,42 +53,24 @@ def retries= new_retries
         # Set the default values
         self.retries = 3
         self.grpc_codes = [14]
-        self.http_codes = [500, 503]
-        self.reasons = %w(rateLimitExceeded userRateLimitExceeded)
         self.backoff = ->(retries) { sleep retries.to_i }
 
         ##
         # @private
-        # Creates a new Backoff object to catch common errors when calling
+        # Creates a new GrpcBackoff object to catch common errors when calling
         # the Google API and handle the error by retrying the call.
         #
-        #   Google::Cloud::Backoff.new(options).execute_gapi do
-        #     client.execute api_method: service.things.insert,
-        #                    parameters: { thing: @thing },
-        #                    body_object: { name: thing_name }
+        #   Google::Cloud::Core::GrpcBackoff.new(options).execute do
+        #     datastore.lookup lookup_req
         #   end
         def initialize options = {}
-          @retries    = (options[:retries]    || Backoff.retries).to_i
-          @grpc_codes = (options[:grpc_codes] || Backoff.grpc_codes).to_a
-          @http_codes = (options[:http_codes] || Backoff.http_codes).to_a
-          @reasons    = (options[:reasons]    || Backoff.reasons).to_a
-          @backoff    =  options[:backoff]    || Backoff.backoff
+          @retries    = (options[:retries]    || GrpcBackoff.retries).to_i
+          @grpc_codes = (options[:grpc_codes] || GrpcBackoff.grpc_codes).to_a
+          @backoff    =  options[:backoff]    || GrpcBackoff.backoff
         end
 
         # @private
-        def execute_gapi
-          current_retries = 0
-          loop do
-            result = yield
-            return result unless result.is_a? Google::APIClient::Result
-            break result if result.success? || !retry?(result, current_retries)
-            current_retries += 1
-            @backoff.call current_retries
-          end
-        end
-
-        # @private
-        def execute_grpc
+        def execute
           current_retries = 0
           loop do
             begin
@@ -114,36 +83,6 @@ def execute_grpc
             end
           end
         end
-
-        protected
-
-        # @private
-        def retry? result, current_retries #:nodoc:
-          if current_retries < @retries
-            return true if retry_http_code? result
-            return true if retry_error_reason? result
-          end
-          false
-        end
-
-        # @private
-        def retry_http_code? result #:nodoc:
-          @http_codes.include? result.response.status
-        end
-
-        # @private
-        def retry_error_reason? result
-          if result.data &&
-             result.data["error"] &&
-             result.data["error"]["errors"]
-            Array(result.data["error"]["errors"]).each do |error|
-              if error["reason"] && @reasons.include?(error["reason"])
-                return true
-              end
-            end
-          end
-          false
-        end
       end
     end
   end
diff --git a/google-cloud-core/lib/google/cloud/core/grpc_backoff.rb b/google-cloud-core/lib/google/cloud/core/grpc_backoff.rb
new file mode 100644
index 000000000000..9e849552397c
--- /dev/null
+++ b/google-cloud-core/lib/google/cloud/core/grpc_backoff.rb
@@ -0,0 +1,89 @@
+# Copyright 2014 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+module Google
+  module Cloud
+    module Core
+      ##
+      # @private
+      # Backoff allows users to control how Google API calls are retried.
+      # If an API call fails the response will be checked to see if the
+      # call can be retried. If the response matches the criteria, then it
+      # will be retried with an incremental backoff. This means that an
+      # increasing delay will be added between each retried call. The first
+      # retry will be delayed one second, the second retry will be delayed
+      # two seconds, and so on.
+      class GrpcBackoff
+        class << self
+          ##
+          # The number of times a retriable API call should be retried.
+          #
+          # The default value is `3`.
+          attr_reader :retries
+          def retries= new_retries
+            @retries = new_retries
+          end
+
+          ##
+          # The GRPC Status Codes that should be retried.
+          #
+          # The default values are `14`.
+          attr_accessor :grpc_codes
+
+          ##
+          # The code to run when a backoff is handled.
+          # This must be a Proc and must take the number of
+          # retries as an argument.
+          #
+          # Note: This method is undocumented and may change.
+          attr_accessor :backoff # :nodoc:
+        end
+        # Set the default values
+        self.retries = 3
+        self.grpc_codes = [14]
+        self.backoff = ->(retries) { sleep retries.to_i }
+
+        ##
+        # @private
+        # Creates a new Backoff object to catch common errors when calling
+        # the Google API and handle the error by retrying the call.
+        #
+        #   Google::Cloud::Core::GrpcBackoff.new(options).execute do
+        #     datastore.lookup lookup_ref
+        #   end
+        def initialize options = {}
+          @retries    = (options[:retries]    || GrpcBackoff.retries).to_i
+          @grpc_codes = (options[:grpc_codes] || GrpcBackoff.grpc_codes).to_a
+          @backoff    =  options[:backoff]    || GrpcBackoff.backoff
+        end
+
+        # @private
+        def execute
+          current_retries = 0
+          loop do
+            begin
+              return yield
+            rescue GRPC::BadStatus => e
+              raise e unless @grpc_codes.include?(e.code) &&
+                             (current_retries < @retries)
+              current_retries += 1
+              @backoff.call current_retries
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/google-cloud-datastore/lib/google/cloud/datastore/dataset.rb b/google-cloud-datastore/lib/google/cloud/datastore/dataset.rb
index e3790e40ccff..6c5c79ec2a24 100644
--- a/google-cloud-datastore/lib/google/cloud/datastore/dataset.rb
+++ b/google-cloud-datastore/lib/google/cloud/datastore/dataset.rb
@@ -89,7 +89,7 @@ def self.default_project
             ENV["DATASTORE_PROJECT"] ||
             ENV["GCLOUD_PROJECT"] ||
             ENV["GOOGLE_CLOUD_PROJECT"] ||
-            Google::Cloud::GCE.project_id
+            Google::Cloud::Core::GCE.project_id
         end
 
         ##
diff --git a/google-cloud-datastore/lib/google/cloud/datastore/service.rb b/google-cloud-datastore/lib/google/cloud/datastore/service.rb
index f0d46502d55b..7b291caa1a48 100644
--- a/google-cloud-datastore/lib/google/cloud/datastore/service.rb
+++ b/google-cloud-datastore/lib/google/cloud/datastore/service.rb
@@ -15,7 +15,7 @@
 
 require "google/cloud/datastore/credentials"
 require "google/datastore/v1beta3/datastore_services"
-require "google/cloud/core/backoff"
+require "google/cloud/core/grpc_backoff"
 
 module Google
   module Cloud
@@ -143,7 +143,7 @@ def inspect
         ##
         # Performs backoff and error handling
         def execute
-          Google::Cloud::Core::Backoff.new(retries: retries).execute_grpc do
+          Google::Cloud::Core::GrpcBackoff.new(retries: retries).execute do
             yield
           end
         rescue GRPC::BadStatus => e
diff --git a/google-cloud-datastore/test/google/cloud/datastore_test.rb b/google-cloud-datastore/test/google/cloud/datastore_test.rb
index 4cffcccdf2af..20deffe2771a 100644
--- a/google-cloud-datastore/test/google/cloud/datastore_test.rb
+++ b/google-cloud-datastore/test/google/cloud/datastore_test.rb
@@ -16,51 +16,104 @@
 require "google/cloud/datastore"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.datastore" do
-    gcloud = Google::Cloud.new
-    stubbed_datastore = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "datastore-dataset-object-empty"
-    }
-    Google::Cloud.stub :datastore, stubbed_datastore do
-      dataset = gcloud.datastore
-      dataset.must_equal "datastore-dataset-object-empty"
+  describe "#datastore" do
+    it "calls out to Google::Cloud.datastore" do
+      gcloud = Google::Cloud.new
+      stubbed_datastore = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "datastore-dataset-object-empty"
+      }
+      Google::Cloud.stub :datastore, stubbed_datastore do
+        dataset = gcloud.datastore
+        dataset.must_equal "datastore-dataset-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.datastore" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_datastore = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "datastore-dataset-object"
+      }
+      Google::Cloud.stub :datastore, stubbed_datastore do
+        dataset = gcloud.datastore
+        dataset.must_equal "datastore-dataset-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.datastore" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_datastore = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "datastore-dataset-object"
-    }
-    Google::Cloud.stub :datastore, stubbed_datastore do
-      dataset = gcloud.datastore
-      dataset.must_equal "datastore-dataset-object"
+    it "passes project and keyfile and options to Google::Cloud.datastore" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_datastore = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "datastore-dataset-object-scoped"
+      }
+      Google::Cloud.stub :datastore, stubbed_datastore do
+        dataset = gcloud.datastore scope: "http://example.com/scope", retries: 5, timeout: 60
+        dataset.must_equal "datastore-dataset-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.datastore" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_datastore = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "datastore-dataset-object-scoped"
-    }
-    Google::Cloud.stub :datastore, stubbed_datastore do
-      dataset = gcloud.datastore scope: "http://example.com/scope", retries: 5, timeout: 60
-      dataset.must_equal "datastore-dataset-object-scoped"
+  describe ".datastore" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Datastore::Credentials.stub :default, default_credentials do
+            datastore = Google::Cloud.datastore
+            datastore.must_be_kind_of Google::Cloud::Datastore::Dataset
+            datastore.project.must_equal "project-id"
+            datastore.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "datastore-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "datastore-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Datastore::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Datastore::Service.stub :new, stubbed_service do
+                datastore = Google::Cloud.datastore "project-id", "path/to/keyfile.json"
+                datastore.must_be_kind_of Google::Cloud::Datastore::Dataset
+                datastore.project.must_equal "project-id"
+                datastore.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-dns/lib/google/cloud/dns/project.rb b/google-cloud-dns/lib/google/cloud/dns/project.rb
index cbce8ebdabcd..5f57eccdecfc 100644
--- a/google-cloud-dns/lib/google/cloud/dns/project.rb
+++ b/google-cloud-dns/lib/google/cloud/dns/project.rb
@@ -130,7 +130,7 @@ def self.default_project
           ENV["DNS_PROJECT"] ||
             ENV["GCLOUD_PROJECT"] ||
             ENV["GOOGLE_CLOUD_PROJECT"] ||
-            Google::Cloud::GCE.project_id
+            Google::Cloud::Core::GCE.project_id
         end
 
         ##
diff --git a/google-cloud-dns/test/google/cloud/dns_test.rb b/google-cloud-dns/test/google/cloud/dns_test.rb
index 1155dc29def2..6573a7c4f14e 100644
--- a/google-cloud-dns/test/google/cloud/dns_test.rb
+++ b/google-cloud-dns/test/google/cloud/dns_test.rb
@@ -16,51 +16,104 @@
 require "google/cloud/dns"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.dns" do
-    gcloud = Google::Cloud.new
-    stubbed_dns = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "dns-project-object-empty"
-    }
-    Google::Cloud.stub :dns, stubbed_dns do
-      project = gcloud.dns
-      project.must_equal "dns-project-object-empty"
+  describe "#dns" do
+    it "calls out to Google::Cloud.dns" do
+      gcloud = Google::Cloud.new
+      stubbed_dns = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "dns-project-object-empty"
+      }
+      Google::Cloud.stub :dns, stubbed_dns do
+        project = gcloud.dns
+        project.must_equal "dns-project-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.dns" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_dns = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "dns-project-object"
+      }
+      Google::Cloud.stub :dns, stubbed_dns do
+        project = gcloud.dns
+        project.must_equal "dns-project-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.dns" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_dns = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "dns-project-object"
-    }
-    Google::Cloud.stub :dns, stubbed_dns do
-      project = gcloud.dns
-      project.must_equal "dns-project-object"
+    it "passes project and keyfile and options to Google::Cloud.dns" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_dns = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "dns-project-object-scoped"
+      }
+      Google::Cloud.stub :dns, stubbed_dns do
+        project = gcloud.dns scope: "http://example.com/scope", retries: 5, timeout: 60
+        project.must_equal "dns-project-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.dns" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_dns = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "dns-project-object-scoped"
-    }
-    Google::Cloud.stub :dns, stubbed_dns do
-      project = gcloud.dns scope: "http://example.com/scope", retries: 5, timeout: 60
-      project.must_equal "dns-project-object-scoped"
+  describe ".dns" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Dns::Credentials.stub :default, default_credentials do
+            dns = Google::Cloud.dns
+            dns.must_be_kind_of Google::Cloud::Dns::Project
+            dns.project.must_equal "project-id"
+            dns.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "dns-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "dns-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Dns::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Dns::Service.stub :new, stubbed_service do
+                dns = Google::Cloud.dns "project-id", "path/to/keyfile.json"
+                dns.must_be_kind_of Google::Cloud::Dns::Project
+                dns.project.must_equal "project-id"
+                dns.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-logging/lib/google/cloud/logging/project.rb b/google-cloud-logging/lib/google/cloud/logging/project.rb
index 5d5e7dfa0d4c..78fc66af3f38 100644
--- a/google-cloud-logging/lib/google/cloud/logging/project.rb
+++ b/google-cloud-logging/lib/google/cloud/logging/project.rb
@@ -78,7 +78,7 @@ def self.default_project
           ENV["LOGGING_PROJECT"] ||
             ENV["GOOGLE_CLOUD_PROJECT"] ||
             ENV["GCLOUD_PROJECT"] ||
-            Google::Cloud::GCE.project_id
+            Google::Cloud::Core::GCE.project_id
         end
 
         ##
diff --git a/google-cloud-logging/lib/google/cloud/logging/service.rb b/google-cloud-logging/lib/google/cloud/logging/service.rb
index b3ba04be4b84..2fe1b2503352 100644
--- a/google-cloud-logging/lib/google/cloud/logging/service.rb
+++ b/google-cloud-logging/lib/google/cloud/logging/service.rb
@@ -14,7 +14,7 @@
 
 
 require "google/cloud/errors"
-require "google/cloud/core/backoff"
+require "google/cloud/core/grpc_backoff"
 require "google/logging/v2/logging_services"
 require "google/logging/v2/logging_config_services"
 require "google/logging/v2/logging_metrics_services"
@@ -258,7 +258,7 @@ def metric_path metric_name
         end
 
         def execute
-          Google::Cloud::Core::Backoff.new(retries: retries).execute_grpc do
+          Google::Cloud::Core::GrpcBackoff.new(retries: retries).execute do
             yield
           end
         rescue GRPC::BadStatus => e
diff --git a/google-cloud-logging/test/google/cloud/logging/backoff_test.rb b/google-cloud-logging/test/google/cloud/logging/backoff_test.rb
index 08da15cdb932..3b1016fd6ff7 100644
--- a/google-cloud-logging/test/google/cloud/logging/backoff_test.rb
+++ b/google-cloud-logging/test/google/cloud/logging/backoff_test.rb
@@ -56,9 +56,9 @@ def assert_backoff_sleep *args
     mock = Minitest::Mock.new
     args.each { |intv| mock.expect :sleep, nil, [intv] }
     callback = ->(retries) { mock.sleep retries }
-    backoff = Google::Cloud::Core::Backoff.new retries: 5, backoff: callback
+    backoff = Google::Cloud::Core::GrpcBackoff.new retries: 5, backoff: callback
 
-    Google::Cloud::Core::Backoff.stub :new, backoff do
+    Google::Cloud::Core::GrpcBackoff.stub :new, backoff do
       yield
     end
 
diff --git a/google-cloud-logging/test/google/cloud/logging_test.rb b/google-cloud-logging/test/google/cloud/logging_test.rb
index 440fa48aa6c5..d16cc92e62d2 100644
--- a/google-cloud-logging/test/google/cloud/logging_test.rb
+++ b/google-cloud-logging/test/google/cloud/logging_test.rb
@@ -16,51 +16,104 @@
 require "google/cloud/logging"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.logging" do
-    gcloud = Google::Cloud.new
-    stubbed_logging = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "logging-project-object-empty"
-    }
-    Google::Cloud.stub :logging, stubbed_logging do
-      project = gcloud.logging
-      project.must_equal "logging-project-object-empty"
+  describe "#logging" do
+    it "calls out to Google::Cloud.logging" do
+      gcloud = Google::Cloud.new
+      stubbed_logging = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "logging-project-object-empty"
+      }
+      Google::Cloud.stub :logging, stubbed_logging do
+        project = gcloud.logging
+        project.must_equal "logging-project-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.logging" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_logging = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "logging-project-object"
+      }
+      Google::Cloud.stub :logging, stubbed_logging do
+        project = gcloud.logging
+        project.must_equal "logging-project-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.logging" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_logging = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "logging-project-object"
-    }
-    Google::Cloud.stub :logging, stubbed_logging do
-      project = gcloud.logging
-      project.must_equal "logging-project-object"
+    it "passes project and keyfile and options to Google::Cloud.logging" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_logging = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "logging-project-object-scoped"
+      }
+      Google::Cloud.stub :logging, stubbed_logging do
+        project = gcloud.logging scope: "http://example.com/scope", retries: 5, timeout: 60
+        project.must_equal "logging-project-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.logging" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_logging = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "logging-project-object-scoped"
-    }
-    Google::Cloud.stub :logging, stubbed_logging do
-      project = gcloud.logging scope: "http://example.com/scope", retries: 5, timeout: 60
-      project.must_equal "logging-project-object-scoped"
+  describe ".logging" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Logging::Credentials.stub :default, default_credentials do
+            logging = Google::Cloud.logging
+            logging.must_be_kind_of Google::Cloud::Logging::Project
+            logging.project.must_equal "project-id"
+            logging.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "logging-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "logging-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Logging::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Logging::Service.stub :new, stubbed_service do
+                logging = Google::Cloud.logging "project-id", "path/to/keyfile.json"
+                logging.must_be_kind_of Google::Cloud::Logging::Project
+                logging.project.must_equal "project-id"
+                logging.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-pubsub/lib/google/cloud/pubsub/project.rb b/google-cloud-pubsub/lib/google/cloud/pubsub/project.rb
index 9f93b24be0ab..06fbe9e51c61 100644
--- a/google-cloud-pubsub/lib/google/cloud/pubsub/project.rb
+++ b/google-cloud-pubsub/lib/google/cloud/pubsub/project.rb
@@ -76,7 +76,7 @@ def self.default_project
           ENV["PUBSUB_PROJECT"] ||
             ENV["GOOGLE_CLOUD_PROJECT"] ||
             ENV["GCLOUD_PROJECT"] ||
-            Google::Cloud::GCE.project_id
+            Google::Cloud::Core::GCE.project_id
         end
 
         ##
diff --git a/google-cloud-pubsub/lib/google/cloud/pubsub/service.rb b/google-cloud-pubsub/lib/google/cloud/pubsub/service.rb
index 331603911164..002dc313e970 100644
--- a/google-cloud-pubsub/lib/google/cloud/pubsub/service.rb
+++ b/google-cloud-pubsub/lib/google/cloud/pubsub/service.rb
@@ -14,7 +14,7 @@
 
 
 require "google/cloud/errors"
-require "google/cloud/core/backoff"
+require "google/cloud/core/grpc_backoff"
 require "google/pubsub/v1/pubsub_services"
 require "google/iam/v1/iam_policy_services"
 require "google/cloud/core/grpc_utils"
@@ -328,7 +328,7 @@ def inspect
         protected
 
         def execute
-          Google::Cloud::Core::Backoff.new(retries: retries).execute_grpc do
+          Google::Cloud::Core::GrpcBackoff.new(retries: retries).execute do
             yield
           end
         rescue GRPC::BadStatus => e
diff --git a/google-cloud-pubsub/test/google/cloud/pubsub/backoff_test.rb b/google-cloud-pubsub/test/google/cloud/pubsub/backoff_test.rb
index 213abfe1b557..f5bc80a4b598 100644
--- a/google-cloud-pubsub/test/google/cloud/pubsub/backoff_test.rb
+++ b/google-cloud-pubsub/test/google/cloud/pubsub/backoff_test.rb
@@ -57,9 +57,9 @@ def assert_backoff_sleep *args
     mock = Minitest::Mock.new
     args.each { |intv| mock.expect :sleep, nil, [intv] }
     callback = ->(retries) { mock.sleep retries }
-    backoff = Google::Cloud::Core::Backoff.new retries: 5, backoff: callback
+    backoff = Google::Cloud::Core::GrpcBackoff.new retries: 5, backoff: callback
 
-    Google::Cloud::Core::Backoff.stub :new, backoff do
+    Google::Cloud::Core::GrpcBackoff.stub :new, backoff do
       yield
     end
 
diff --git a/google-cloud-pubsub/test/google/cloud/pubsub_test.rb b/google-cloud-pubsub/test/google/cloud/pubsub_test.rb
index 744a3fb2ff17..8f10aec64a9b 100644
--- a/google-cloud-pubsub/test/google/cloud/pubsub_test.rb
+++ b/google-cloud-pubsub/test/google/cloud/pubsub_test.rb
@@ -16,51 +16,104 @@
 require "google/cloud/pubsub"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.pubsub" do
-    gcloud = Google::Cloud.new
-    stubbed_pubsub = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "pubsub-project-object-empty"
-    }
-    Google::Cloud.stub :pubsub, stubbed_pubsub do
-      project = gcloud.pubsub
-      project.must_equal "pubsub-project-object-empty"
+  describe "#pubsub" do
+    it "calls out to Google::Cloud.pubsub" do
+      gcloud = Google::Cloud.new
+      stubbed_pubsub = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "pubsub-project-object-empty"
+      }
+      Google::Cloud.stub :pubsub, stubbed_pubsub do
+        project = gcloud.pubsub
+        project.must_equal "pubsub-project-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.pubsub" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_pubsub = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "pubsub-project-object"
+      }
+      Google::Cloud.stub :pubsub, stubbed_pubsub do
+        project = gcloud.pubsub
+        project.must_equal "pubsub-project-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.pubsub" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_pubsub = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "pubsub-project-object"
-    }
-    Google::Cloud.stub :pubsub, stubbed_pubsub do
-      project = gcloud.pubsub
-      project.must_equal "pubsub-project-object"
+    it "passes project and keyfile and options to Google::Cloud.pubsub" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_pubsub = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "pubsub-project-object-scoped"
+      }
+      Google::Cloud.stub :pubsub, stubbed_pubsub do
+        project = gcloud.pubsub scope: "http://example.com/scope", retries: 5, timeout: 60
+        project.must_equal "pubsub-project-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.pubsub" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_pubsub = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "pubsub-project-object-scoped"
-    }
-    Google::Cloud.stub :pubsub, stubbed_pubsub do
-      project = gcloud.pubsub scope: "http://example.com/scope", retries: 5, timeout: 60
-      project.must_equal "pubsub-project-object-scoped"
+  describe ".pubsub" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Pubsub::Credentials.stub :default, default_credentials do
+            pubsub = Google::Cloud.pubsub
+            pubsub.must_be_kind_of Google::Cloud::Pubsub::Project
+            pubsub.project.must_equal "project-id"
+            pubsub.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "pubsub-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "pubsub-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Pubsub::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Pubsub::Service.stub :new, stubbed_service do
+                pubsub = Google::Cloud.pubsub "project-id", "path/to/keyfile.json"
+                pubsub.must_be_kind_of Google::Cloud::Pubsub::Project
+                pubsub.project.must_equal "project-id"
+                pubsub.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-resource_manager/test/google/cloud/resource_manager_test.rb b/google-cloud-resource_manager/test/google/cloud/resource_manager_test.rb
index a9b34027afe8..76908006ac27 100644
--- a/google-cloud-resource_manager/test/google/cloud/resource_manager_test.rb
+++ b/google-cloud-resource_manager/test/google/cloud/resource_manager_test.rb
@@ -16,48 +16,98 @@
 require "google/cloud/resource_manager"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.resource_manager" do
-    gcloud = Google::Cloud.new
-    stubbed_resource_manager = ->(keyfile, scope: nil, retries: nil, timeout: nil) {
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "resource_manager-manager-object-empty"
-    }
-    Google::Cloud.stub :resource_manager, stubbed_resource_manager do
-      manager = gcloud.resource_manager
-      manager.must_equal "resource_manager-manager-object-empty"
+  describe "#resource_manager" do
+    it "calls out to Google::Cloud.resource_manager" do
+      gcloud = Google::Cloud.new
+      stubbed_resource_manager = ->(keyfile, scope: nil, retries: nil, timeout: nil) {
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "resource_manager-manager-object-empty"
+      }
+      Google::Cloud.stub :resource_manager, stubbed_resource_manager do
+        manager = gcloud.resource_manager
+        manager.must_equal "resource_manager-manager-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.resource_manager" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_resource_manager = ->(keyfile, scope: nil, retries: nil, timeout: nil) {
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "resource_manager-manager-object"
+      }
+      Google::Cloud.stub :resource_manager, stubbed_resource_manager do
+        manager = gcloud.resource_manager
+        manager.must_equal "resource_manager-manager-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.resource_manager" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_resource_manager = ->(keyfile, scope: nil, retries: nil, timeout: nil) {
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "resource_manager-manager-object"
-    }
-    Google::Cloud.stub :resource_manager, stubbed_resource_manager do
-      manager = gcloud.resource_manager
-      manager.must_equal "resource_manager-manager-object"
+    it "passes project and keyfile and options to Google::Cloud.resource_manager" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_resource_manager = ->(keyfile, scope: nil, retries: nil, timeout: nil) {
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "resource_manager-manager-object-scoped"
+      }
+      Google::Cloud.stub :resource_manager, stubbed_resource_manager do
+        manager = gcloud.resource_manager scope: "http://example.com/scope", retries: 5, timeout: 60
+        manager.must_equal "resource_manager-manager-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.resource_manager" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_resource_manager = ->(keyfile, scope: nil, retries: nil, timeout: nil) {
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "resource_manager-manager-object-scoped"
-    }
-    Google::Cloud.stub :resource_manager, stubbed_resource_manager do
-      manager = gcloud.resource_manager scope: "http://example.com/scope", retries: 5, timeout: 60
-      manager.must_equal "resource_manager-manager-object-scoped"
+  describe ".resource_manager" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::ResourceManager::Credentials.stub :default, default_credentials do
+            resource_manager = Google::Cloud.resource_manager
+            resource_manager.must_be_kind_of Google::Cloud::ResourceManager::Manager
+            resource_manager.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "resource_manager-credentials"
+      }
+      stubbed_service = ->(credentials, retries: nil, timeout: nil) {
+        credentials.must_equal "resource_manager-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::ResourceManager::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::ResourceManager::Service.stub :new, stubbed_service do
+                resource_manager = Google::Cloud.resource_manager "path/to/keyfile.json"
+                resource_manager.must_be_kind_of Google::Cloud::ResourceManager::Manager
+                resource_manager.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-storage/lib/google/cloud/storage/project.rb b/google-cloud-storage/lib/google/cloud/storage/project.rb
index 833b6a609cc3..131fa665a586 100644
--- a/google-cloud-storage/lib/google/cloud/storage/project.rb
+++ b/google-cloud-storage/lib/google/cloud/storage/project.rb
@@ -82,7 +82,7 @@ def self.default_project
           ENV["STORAGE_PROJECT"] ||
             ENV["GOOGLE_CLOUD_PROJECT"] ||
             ENV["GCLOUD_PROJECT"] ||
-            Google::Cloud::GCE.project_id
+            Google::Cloud::Core::GCE.project_id
         end
 
         ##
diff --git a/google-cloud-storage/lib/google/cloud/storage/service.rb b/google-cloud-storage/lib/google/cloud/storage/service.rb
index 98f9169f29a9..62afaccef3d9 100644
--- a/google-cloud-storage/lib/google/cloud/storage/service.rb
+++ b/google-cloud-storage/lib/google/cloud/storage/service.rb
@@ -14,7 +14,7 @@
 
 
 require "google/cloud/storage/version"
-require "google/cloud/core/backoff"
+require "google/cloud/core/grpc_backoff"
 require "google/apis/storage_v1"
 require "digest"
 require "mime/types"
diff --git a/google-cloud-storage/test/google/cloud/storage_test.rb b/google-cloud-storage/test/google/cloud/storage_test.rb
index 222fc89fdb6c..66b78f5cc3b7 100644
--- a/google-cloud-storage/test/google/cloud/storage_test.rb
+++ b/google-cloud-storage/test/google/cloud/storage_test.rb
@@ -16,51 +16,104 @@
 require "google/cloud/storage"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.storage" do
-    gcloud = Google::Cloud.new
-    stubbed_storage = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "storage-project-object-empty"
-    }
-    Google::Cloud.stub :storage, stubbed_storage do
-      project = gcloud.storage
-      project.must_equal "storage-project-object-empty"
+  describe "#storage" do
+    it "calls out to Google::Cloud.storage" do
+      gcloud = Google::Cloud.new
+      stubbed_storage = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "storage-project-object-empty"
+      }
+      Google::Cloud.stub :storage, stubbed_storage do
+        project = gcloud.storage
+        project.must_equal "storage-project-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.storage" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_storage = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "storage-project-object"
+      }
+      Google::Cloud.stub :storage, stubbed_storage do
+        project = gcloud.storage
+        project.must_equal "storage-project-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.storage" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_storage = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "storage-project-object"
-    }
-    Google::Cloud.stub :storage, stubbed_storage do
-      project = gcloud.storage
-      project.must_equal "storage-project-object"
+    it "passes project and keyfile and options to Google::Cloud.storage" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_storage = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "storage-project-object-scoped"
+      }
+      Google::Cloud.stub :storage, stubbed_storage do
+        project = gcloud.storage scope: "http://example.com/scope", retries: 5, timeout: 60
+        project.must_equal "storage-project-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.storage" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_storage = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "storage-project-object-scoped"
-    }
-    Google::Cloud.stub :storage, stubbed_storage do
-      project = gcloud.storage scope: "http://example.com/scope", retries: 5, timeout: 60
-      project.must_equal "storage-project-object-scoped"
+  describe ".storage" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Storage::Credentials.stub :default, default_credentials do
+            storage = Google::Cloud.storage
+            storage.must_be_kind_of Google::Cloud::Storage::Project
+            storage.project.must_equal "project-id"
+            storage.service.credentials.must_equal default_credentials
+          end
+        end
+      end
     end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "storage-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "storage-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Storage::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Storage::Service.stub :new, stubbed_service do
+                storage = Google::Cloud.storage "project-id", "path/to/keyfile.json"
+                storage.must_be_kind_of Google::Cloud::Storage::Project
+                storage.project.must_equal "project-id"
+                storage.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
+    end
+  end
   end
-end
diff --git a/google-cloud-translate/test/google/cloud/translate_test.rb b/google-cloud-translate/test/google/cloud/translate_test.rb
index 95244b2922a6..9f590dbf88c6 100644
--- a/google-cloud-translate/test/google/cloud/translate_test.rb
+++ b/google-cloud-translate/test/google/cloud/translate_test.rb
@@ -16,45 +16,91 @@
 require "google/cloud/translate"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.translate" do
-    gcloud = Google::Cloud.new
-    stubbed_translate = ->(key, retries: nil, timeout: nil) {
-      key.must_equal "this-is-the-api-key"
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "translate-api-object-empty"
-    }
-    Google::Cloud.stub :translate, stubbed_translate do
-      api = gcloud.translate "this-is-the-api-key"
-      api.must_equal "translate-api-object-empty"
+  describe "#translate" do
+    it "calls out to Google::Cloud.translate" do
+      gcloud = Google::Cloud.new
+      stubbed_translate = ->(key, retries: nil, timeout: nil) {
+        key.must_equal "this-is-the-api-key"
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "translate-api-object-empty"
+      }
+      Google::Cloud.stub :translate, stubbed_translate do
+        api = gcloud.translate "this-is-the-api-key"
+        api.must_equal "translate-api-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.translate" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_translate = ->(key, retries: nil, timeout: nil) {
+        key.must_equal "this-is-the-api-key"
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "translate-api-object"
+      }
+      Google::Cloud.stub :translate, stubbed_translate do
+        api = gcloud.translate "this-is-the-api-key"
+        api.must_equal "translate-api-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.translate" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_translate = ->(key, retries: nil, timeout: nil) {
-      key.must_equal "this-is-the-api-key"
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "translate-api-object"
-    }
-    Google::Cloud.stub :translate, stubbed_translate do
-      api = gcloud.translate "this-is-the-api-key"
-      api.must_equal "translate-api-object"
+    it "passes project and keyfile and options to Google::Cloud.translate" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_translate = ->(key, retries: nil, timeout: nil) {
+        key.must_equal "this-is-the-api-key"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "translate-api-object-scoped"
+      }
+      Google::Cloud.stub :translate, stubbed_translate do
+        api = gcloud.translate "this-is-the-api-key", retries: 5, timeout: 60
+        api.must_equal "translate-api-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.translate" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_translate = ->(key, retries: nil, timeout: nil) {
-      key.must_equal "this-is-the-api-key"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "translate-api-object-scoped"
-    }
-    Google::Cloud.stub :translate, stubbed_translate do
-      api = gcloud.translate "this-is-the-api-key", retries: 5, timeout: 60
-      api.must_equal "translate-api-object-scoped"
+  describe ".translate" do
+    it "gets defaults for api_key" do
+      stubbed_env = ->(name) {
+        "found-api-key" if name == "GOOGLE_CLOUD_KEY"
+      }
+      stubbed_service = ->(key, retries: nil, timeout: nil) {
+        key.must_equal "found-api-key"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new key: key
+      }
+
+      # Clear all environment variables
+      # ENV.stub :[], nil do
+      ENV.stub :[], stubbed_env do
+        Google::Cloud::Translate::Service.stub :new, stubbed_service do
+          translate = Google::Cloud.translate
+          translate.must_be_kind_of Google::Cloud::Translate::Api
+          translate.service.must_be_kind_of OpenStruct
+          translate.service.key.must_equal "found-api-key"
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_service = ->(key, retries: nil, timeout: nil) {
+        key.must_equal "my-api-key"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new key: key
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        Google::Cloud::Translate::Service.stub :new, stubbed_service do
+          translate = Google::Cloud.translate "my-api-key"
+          translate.must_be_kind_of Google::Cloud::Translate::Api
+          translate.service.must_be_kind_of OpenStruct
+          translate.service.key.must_equal "my-api-key"
+        end
+      end
     end
   end
 end
diff --git a/google-cloud-vision/lib/google/cloud/vision/project.rb b/google-cloud-vision/lib/google/cloud/vision/project.rb
index 0a2ce4434eac..e1a15d0880ec 100644
--- a/google-cloud-vision/lib/google/cloud/vision/project.rb
+++ b/google-cloud-vision/lib/google/cloud/vision/project.rb
@@ -79,7 +79,7 @@ def self.default_project
           ENV["VISION_PROJECT"] ||
             ENV["GOOGLE_CLOUD_PROJECT"] ||
             ENV["GCLOUD_PROJECT"] ||
-            Google::Cloud::GCE.project_id
+            Google::Cloud::Core::GCE.project_id
         end
 
         ##
diff --git a/google-cloud-vision/test/google/cloud/vision_test.rb b/google-cloud-vision/test/google/cloud/vision_test.rb
index 098d451a66ee..c88396873d9a 100644
--- a/google-cloud-vision/test/google/cloud/vision_test.rb
+++ b/google-cloud-vision/test/google/cloud/vision_test.rb
@@ -14,53 +14,107 @@
 
 require "helper"
 require "google/cloud/vision"
+require "google/cloud/core/gce"
 
 describe Google::Cloud do
-  it "calls out to Google::Cloud.vision" do
-    gcloud = Google::Cloud.new
-    stubbed_vision = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal nil
-      keyfile.must_equal nil
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "vision-project-object-empty"
-    }
-    Google::Cloud.stub :vision, stubbed_vision do
-      project = gcloud.vision
-      project.must_equal "vision-project-object-empty"
+  describe "#vision" do
+    it "calls out to Google::Cloud.vision" do
+      gcloud = Google::Cloud.new
+      stubbed_vision = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal nil
+        keyfile.must_equal nil
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "vision-project-object-empty"
+      }
+      Google::Cloud.stub :vision, stubbed_vision do
+        project = gcloud.vision
+        project.must_equal "vision-project-object-empty"
+      end
+    end
+
+    it "passes project and keyfile to Google::Cloud.vision" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_vision = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_be :nil?
+        retries.must_be :nil?
+        timeout.must_be :nil?
+        "vision-project-object"
+      }
+      Google::Cloud.stub :vision, stubbed_vision do
+        project = gcloud.vision
+        project.must_equal "vision-project-object"
+      end
     end
-  end
 
-  it "passes project and keyfile to Google::Cloud.vision" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_vision = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_be :nil?
-      retries.must_be :nil?
-      timeout.must_be :nil?
-      "vision-project-object"
-    }
-    Google::Cloud.stub :vision, stubbed_vision do
-      project = gcloud.vision
-      project.must_equal "vision-project-object"
+    it "passes project and keyfile and options to Google::Cloud.vision" do
+      gcloud = Google::Cloud.new "project-id", "keyfile-path"
+      stubbed_vision = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        keyfile.must_equal "keyfile-path"
+        scope.must_equal "http://example.com/scope"
+        retries.must_equal 5
+        timeout.must_equal 60
+        "vision-project-object-scoped"
+      }
+      Google::Cloud.stub :vision, stubbed_vision do
+        project = gcloud.vision scope: "http://example.com/scope", retries: 5, timeout: 60
+        project.must_equal "vision-project-object-scoped"
+      end
     end
   end
 
-  it "passes project and keyfile and options to Google::Cloud.vision" do
-    gcloud = Google::Cloud.new "project-id", "keyfile-path"
-    stubbed_vision = ->(project, keyfile, scope: nil, retries: nil, timeout: nil) {
-      project.must_equal "project-id"
-      keyfile.must_equal "keyfile-path"
-      scope.must_equal "http://example.com/scope"
-      retries.must_equal 5
-      timeout.must_equal 60
-      "vision-project-object-scoped"
-    }
-    Google::Cloud.stub :vision, stubbed_vision do
-      project = gcloud.vision scope: "http://example.com/scope", retries: 5, timeout: 60
-      project.must_equal "vision-project-object-scoped"
+  describe ".vision" do
+    let(:default_credentials) { OpenStruct.new empty: true }
+    let(:found_credentials) { "{}" }
+
+    it "gets defaults for project_id and keyfile" do
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        # Get project_id from Google Compute Engine
+        Google::Cloud::Core::GCE.stub :project_id, "project-id" do
+          Google::Cloud::Vision::Credentials.stub :default, default_credentials do
+            vision = Google::Cloud.vision
+            vision.must_be_kind_of Google::Cloud::Vision::Project
+            vision.project.must_equal "project-id"
+            vision.service.credentials.must_equal default_credentials
+          end
+        end
+      end
+    end
+
+    it "uses provided project_id and keyfile" do
+      stubbed_credentials = ->(keyfile, scope: nil) {
+        keyfile.must_equal "path/to/keyfile.json"
+        scope.must_equal nil
+        "vision-credentials"
+      }
+      stubbed_service = ->(project, credentials, retries: nil, timeout: nil) {
+        project.must_equal "project-id"
+        credentials.must_equal "vision-credentials"
+        retries.must_equal nil
+        timeout.must_equal nil
+        OpenStruct.new project: project
+      }
+
+      # Clear all environment variables
+      ENV.stub :[], nil do
+        File.stub :file?, true, ["path/to/keyfile.json"] do
+          File.stub :read, found_credentials, ["path/to/keyfile.json"] do
+            Google::Cloud::Vision::Credentials.stub :new, stubbed_credentials do
+              Google::Cloud::Vision::Service.stub :new, stubbed_service do
+                vision = Google::Cloud.vision "project-id", "path/to/keyfile.json"
+                vision.must_be_kind_of Google::Cloud::Vision::Project
+                vision.project.must_equal "project-id"
+                vision.service.must_be_kind_of OpenStruct
+              end
+            end
+          end
+        end
+      end
     end
   end
 end