Fix emails on push for new and deleted branches

app/workers/emails_on_push_worker.rb

@@ -28,12 +28,12 @@ class EmailsOnPushWorker
         :push
       end
 
-    merge_base_sha = project.merge_base_commit(before_sha, after_sha).try(:sha)
-
     diff_refs = nil
     compare = nil
     reverse_compare = false
+
     if action == :push
+      merge_base_sha = project.merge_base_commit(before_sha, after_sha).try(:sha)
       compare = Gitlab::Git::Compare.new(project.repository.raw_repository, before_sha, after_sha)
 
       diff_refs = Gitlab::Diff::DiffRefs.new(

spec/workers/emails_on_push_worker_spec.rb

@@ -12,6 +12,42 @@ describe EmailsOnPushWorker do
   subject { EmailsOnPushWorker.new }
 
   describe "#perform" do
+    context "when push is a new branch" do
+      let(:email) { ActionMailer::Base.deliveries.last }
+
+      before do
+        data_new_branch = data.stringify_keys.merge("before" => Gitlab::Git::BLANK_SHA)
+
+        subject.perform(project.id, recipients, data_new_branch)
+      end
+
+      it "sends a mail with the correct subject" do
+        expect(email.subject).to include("Pushed new branch")
+      end
+
+      it "sends the mail to the correct recipient" do
+        expect(email.to).to eq([user.email])
+      end
+    end
+
+    context "when push is a deleted branch" do
+      let(:email) { ActionMailer::Base.deliveries.last }
+
+      before do
+        data_deleted_branch = data.stringify_keys.merge("after" => Gitlab::Git::BLANK_SHA)
+
+        subject.perform(project.id, recipients, data_deleted_branch)
+      end
+
+      it "sends a mail with the correct subject" do
+        expect(email.subject).to include("Deleted branch")
+      end
+
+      it "sends the mail to the correct recipient" do
+        expect(email.to).to eq([user.email])
+      end
+    end
+
     context "when there are no errors in sending" do
       let(:email) { ActionMailer::Base.deliveries.last }