Decouple tests from GovukEnvironment.production?

Wherever we were stubbing GovukEnvironment.name, we now always stub
GovukEnvironment.production? to make the tests less brittle.

I'm planning to change the implementation of
GovukEnvironment.production? in a subsequent commit and this change will
avoid the distraction of a bunch of tests failing.

test/helpers/two_step_verification_helper_test.rb

@@ -18,7 +18,7 @@ class TwoStepVerificationHelperTest < ActionView::TestCase
 
     context "in production" do
       setup do
-        GovukEnvironment.stubs(:name).returns(nil)
+        GovukEnvironment.stubs(:production?).returns(true)
       end
 
       should "not include the environment name" do

test/models/noisy_batch_invitation_test.rb

@@ -34,8 +34,9 @@ class NoisyBatchInvitationTest < ActionMailer::TestCase
     end
   end
 
-  context "make_noise when instance_name has been set" do
+  context "make_noise in non-production environment" do
     setup do
+      GovukEnvironment.stubs(:production?).returns(false)
       GovukEnvironment.stubs(:name).returns("Test Fools")
 
       user = create(:user, name: "Bob Loblaw")
@@ -44,22 +45,22 @@ class NoisyBatchInvitationTest < ActionMailer::TestCase
       @email = NoisyBatchInvitation.make_noise(@batch_invitation).deliver_now
     end
 
-    should "from address should include the instance name" do
+    should "from address should include the environment name" do
       assert_match(/".* Signon Test Fools" <noreply-signon-test-fools@.*\.gov\.uk>/, @email[:from].to_s)
     end
   end
 
-  context "work correctly when no instance name is set" do
+  context "work correctly in production environment" do
     setup do
-      GovukEnvironment.stubs(:name).returns(nil)
+      GovukEnvironment.stubs(:production?).returns(true)
 
       user = create(:user, name: "Bob Loblaw")
       @batch_invitation = create(:batch_invitation, user:)
       create(:batch_invitation_user, batch_invitation: @batch_invitation)
       @email = NoisyBatchInvitation.make_noise(@batch_invitation).deliver_now
     end
 
-    should "from address should include the instance name" do
+    should "from address should not include the environment name" do
       assert_match(/".* Signon" <noreply-signon@.*\.gov\.uk>/, @email[:from].to_s)
     end
   end

test/models/user_mailer_test.rb

@@ -22,6 +22,7 @@ def assert_support_present_in_text(link_text, email = @email)
 
     context "in a non-production environment" do
       setup do
+        GovukEnvironment.stubs(:production?).returns(false)
         GovukEnvironment.stubs(:name).returns("foobar")
       end
 
@@ -36,7 +37,7 @@ def assert_support_present_in_text(link_text, email = @email)
 
     context "in the production environment" do
       setup do
-        GovukEnvironment.stubs(:name).returns(nil)
+        GovukEnvironment.stubs(:production?).returns(true)
       end
 
       should "not include the environment in the subject" do
@@ -119,6 +120,7 @@ def assert_support_present_in_text(link_text, email = @email)
 
   context "email a user to notify of suspension" do
     setup do
+      GovukEnvironment.stubs(:production?).returns(false)
       GovukEnvironment.stubs(:name).returns("test")
       stub_user = stub(name: "User", email: "user@example.com")
       @email = UserMailer.suspension_notification(stub_user)
@@ -137,8 +139,9 @@ def assert_support_present_in_text(link_text, email = @email)
     end
   end
 
-  context "on a named Signon instance" do
+  context "on a non-production Signon instance" do
     setup do
+      GovukEnvironment.stubs(:production?).returns(false)
       GovukEnvironment.stubs(:name).returns("test")
       stub_user = stub(name: "User", email: "user@example.com")
       @email = UserMailer.suspension_reminder(stub_user, 3)
@@ -155,6 +158,7 @@ def assert_support_present_in_text(link_text, email = @email)
 
   context "emailing a user to explain why their account is locked" do
     setup do
+      GovukEnvironment.stubs(:production?).returns(false)
       GovukEnvironment.stubs(:name).returns("test")
       @the_time = Time.zone.now
       user = User.new(name: "User", email: "user@example.com", locked_at: @the_time)

test/models/user_test.rb

@@ -5,7 +5,7 @@ class UserTest < ActiveSupport::TestCase
   include ActiveJob::TestHelper
 
   def setup
-    GovukEnvironment.stubs(:name).returns(nil)
+    GovukEnvironment.stubs(:production?).returns(true)
 
     @user = create(:user)
   end
@@ -21,6 +21,7 @@ def setup
     end
 
     should "default to false for admins and superadmins in non-production" do
+      GovukEnvironment.stubs(:production?).returns(false)
       GovukEnvironment.stubs(:name).returns("foobar")
 
       assert_not create(:admin_user).require_2sv?