Change the alert specs to use webmock

When implementing the unpublishing alert feature, we merged code with
a bug which was passing all the tests.  The bug was that we were
calling a method in gds-api-adapters with incorrect arguments.

This bug passed the tests because the tests do not actually use
gds-api-adapters, they mock those methods and check that the mocked
methods are called appropriately.

This is a problem for two reasons:

1. It let us write code which looked correct and even passed tests,
but which could only have been verified as correct by consulting a
different repository.

2. An update to gds-api-adapters could change the method signature and
our tests would continue to pass on the dependabot branch, even though
merging it would break the service.

The point of testing is to catch bugs.  If a test actively obscures
bugs, it should be fixed.  This commit fixes the issue by using
webmock to check the actual calls we make to email-alert-api, rather
than stubbing the methods in gds-api-adapters.

spec/models/email_alert_spec.rb

@@ -47,17 +47,17 @@ def with_lock_unless_done
   end
 
   let(:logger) { double(:logger, info: nil) }
-  let(:alert_api) { double(:alert_api, create_content_change: nil) }
   let(:email_alert) { EmailAlert.new(document, logger) }
   let(:fake_lock_handler) { fake_lock_handler_class.new }
 
   before :each do
-    allow(Services).to receive(:email_api_client).and_return(alert_api)
     allow(LockHandler).to receive(:new).and_return(fake_lock_handler)
   end
 
   describe "#trigger" do
     it "logs receiving a major change notification for a document" do
+      stub_create_content_change.to_return(status: 202)
+
       email_alert.trigger
 
       expect(logger).to have_received(:info).with(
@@ -66,16 +66,18 @@ def with_lock_unless_done
     end
 
     it "sends an alert to the Email Alert API" do
+      stub = stub_create_content_change
+        .with(body: hash_including(content_id: content_id), headers: { "GOVUK-Request-Id" => govuk_request_id })
+        .to_return(status: 202)
+
       email_alert.trigger
 
-      expect(alert_api).to have_received(:create_content_change).with(
-        hash_including("content_id" => content_id),
-        govuk_request_id: govuk_request_id,
-      )
+      expect(stub).to have_been_made
     end
 
     it "logs if it receives a conflict" do
-      allow(alert_api).to receive(:create_content_change).and_raise(GdsApi::HTTPConflict.new(409))
+      stub_create_content_change.to_return(status: 409)
+
       email_alert.trigger
 
       expect(logger).to have_received(:info).with(
@@ -84,13 +86,18 @@ def with_lock_unless_done
     end
 
     it "logs if it receives an unprocessable entity" do
-      allow(alert_api).to receive(:create_content_change).and_raise(GdsApi::HTTPUnprocessableEntity.new(422))
+      stub_create_content_change.to_return(status: 422)
+
       email_alert.trigger
 
       expect(logger).to have_received(:info).with(
         "email-alert-api returned unprocessable entity for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
       )
     end
+
+    def stub_create_content_change
+      stub_request(:post, "#{GdsApi::TestHelpers::EmailAlertApi::EMAIL_ALERT_API_ENDPOINT}/content-changes")
+    end
   end
 
   describe "#format_for_email_api" do

spec/models/unpublishing_alert_spec.rb

@@ -69,59 +69,82 @@ def with_lock_unless_done
       },
     }
   end
-  let(:alert_api) { double(:alert_api, bulk_unsubscribe: nil, find_subscriber_list: subscriber_list_response) }
-
   before :each do
     allow(LockHandler).to receive(:new).and_return(fake_lock_handler)
-    allow(Services).to receive(:email_api_client).and_return(alert_api)
   end
 
   describe "#trigger" do
     shared_examples "a request to bulk unsubscribe with appropriate logging" do
-      it "logs an unsubscription notification" do
+      it "logs that the list does not exist and does not make a request to bulk-unsubscribe" do
+        stub_email_alert_api_does_not_have_subscriber_list("content_id" => content_id)
+
         unpublishing_alert.trigger
 
         expect(logger).to have_received(:info).with(
-          "Received unsubscription notification for #{document['base_path']}, unpublishing_scenario: #{unpublishing_scenario}, full payload: #{document}",
+          "subscriber list not found for content id #{document['content_id']}",
         )
       end
 
-      it "sends a bulk unsubscribe request to the Email Alert API" do
-        unpublishing_alert.trigger
+      context "when the list exists" do
+        before do
+          stub_email_alert_api_has_subscriber_list(
+            "content_id" => content_id,
+            "slug" => subscriber_list_slug,
+          )
+        end
 
-        expect(alert_api).to have_received(:bulk_unsubscribe).with(
-          slug: subscriber_list_slug,
-          govuk_request_id: govuk_request_id,
-          body: email_markdown.strip,
-          sender_message_id: sender_message_id,
-        )
-      end
+        it "logs an unsubscription notification" do
+          stub_email_alert_api_bulk_unsubscribe(slug: subscriber_list_slug)
 
-      it "logs if it recieves a conflict" do
-        allow(alert_api).to receive(:bulk_unsubscribe).and_raise(GdsApi::HTTPConflict.new(409))
-        unpublishing_alert.trigger
+          unpublishing_alert.trigger
 
-        expect(logger).to have_received(:info).with(
-          "email-alert-api returned conflict for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
-        )
-      end
+          expect(logger).to have_received(:info).with(
+            "Received unsubscription notification for #{document['base_path']}, unpublishing_scenario: #{unpublishing_scenario}, full payload: #{document}",
+          )
+        end
 
-      it "logs if it recieves an unprocessable entity" do
-        allow(alert_api).to receive(:bulk_unsubscribe).and_raise(GdsApi::HTTPUnprocessableEntity.new(422))
-        unpublishing_alert.trigger
+        it "sends a bulk unsubscribe request to the Email Alert API" do
+          stub = stub_email_alert_api_bulk_unsubscribe_with_message(
+            slug: subscriber_list_slug,
+            govuk_request_id: govuk_request_id,
+            body: email_markdown.strip,
+            sender_message_id: sender_message_id,
+          )
 
-        expect(logger).to have_received(:info).with(
-          "email-alert-api returned unprocessable entity for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
-        )
-      end
+          unpublishing_alert.trigger
 
-      it "logs if it recieves not found" do
-        allow(alert_api).to receive(:bulk_unsubscribe).and_raise(GdsApi::HTTPNotFound.new(404))
-        unpublishing_alert.trigger
+          expect(stub).to have_been_made
+        end
 
-        expect(logger).to have_received(:info).with(
-          "email-alert-api returned not_found for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
-        )
+        it "logs if it receives a conflict" do
+          stub_email_alert_api_bulk_unsubscribe_conflict(slug: subscriber_list_slug)
+
+          unpublishing_alert.trigger
+
+          expect(logger).to have_received(:info).with(
+            "email-alert-api returned conflict for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
+          )
+        end
+
+        it "logs if it receives an unprocessable entity" do
+          stub_email_alert_api_bulk_unsubscribe_bad_request(slug: subscriber_list_slug)
+
+          unpublishing_alert.trigger
+
+          expect(logger).to have_received(:info).with(
+            "email-alert-api returned unprocessable entity for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
+          )
+        end
+
+        it "logs if it receives not found" do
+          stub_email_alert_api_bulk_unsubscribe_not_found(slug: subscriber_list_slug)
+
+          unpublishing_alert.trigger
+
+          expect(logger).to have_received(:info).with(
+            "email-alert-api returned not_found for #{document['content_id']}, #{document['base_path']}, #{document['public_updated_at']}",
+          )
+        end
       end
     end