Create merge request from email

* new merge request can be created by sending an email to the specific
email address (similar to creating issues by email)
* for the first iteration, source branch must be specified in the mail
subject, other merge request parameters can not be set yet
* user should enable "Receive notifications about your own activity" in
user settings to receive a notification about created merge request

Part of #32878

2 files changed, 101 insertions, 0 deletions

diff --git a/spec/lib/gitlab/email/handler/create_merge_request_handler_spec.rb b/spec/lib/gitlab/email/handler/create_merge_request_handler_spec.rb
new file mode 100644
index 00000000000..e361d1a7393
--- /dev/null
+++ b/spec/lib/gitlab/email/handler/create_merge_request_handler_spec.rb
@@ -0,0 +1,84 @@
+require 'spec_helper'
+require_relative '../email_shared_blocks'
+
+describe Gitlab::Email::Handler::CreateMergeRequestHandler do
+  include_context :email_shared_context
+  it_behaves_like :reply_processing_shared_examples
+
+  before do
+    stub_incoming_email_setting(enabled: true, address: "incoming+%{key}@appmail.adventuretime.ooo")
+    stub_config_setting(host: 'localhost')
+  end
+
+  let(:email_raw) { fixture_file('emails/valid_new_merge_request.eml') }
+  let(:namespace) { create(:namespace, path: 'gitlabhq') }
+
+  # project's git repository is not deleted when project is deleted
+  # between tests. Then tests fail because re-creation of the project with
+  # the same name fails on existing git repository -> skip_disk_validation
+  # ignores repository existence on disk
+  let!(:project)  { create(:project, :public, :repository, skip_disk_validation: true, namespace: namespace, path: 'gitlabhq') }
+  let!(:user) do
+    create(
+      :user,
+      email: 'jake@adventuretime.ooo',
+      incoming_email_token: 'auth_token'
+    )
+  end
+
+  context "as a non-developer" do
+    before do
+      project.add_guest(user)
+    end
+
+    it "raises UserNotAuthorizedError if the user is not a member" do
+      expect { receiver.execute }.to raise_error(Gitlab::Email::UserNotAuthorizedError)
+    end
+  end
+
+  context "as a developer" do
+    before do
+      project.add_developer(user)
+    end
+
+    context "when everything is fine" do
+      it "creates a new merge request" do
+        expect { receiver.execute }.to change { project.merge_requests.count }.by(1)
+        merge_request = project.merge_requests.last
+
+        expect(merge_request.author).to eq(user)
+        expect(merge_request.source_branch).to eq('feature')
+        expect(merge_request.title).to eq('Feature added')
+        expect(merge_request.target_branch).to eq(project.default_branch)
+      end
+    end
+
+    context "something is wrong" do
+      context "when the merge request could not be saved" do
+        before do
+          allow_any_instance_of(MergeRequest).to receive(:save).and_return(false)
+        end
+
+        it "raises an InvalidMergeRequestError" do
+          expect { receiver.execute }.to raise_error(Gitlab::Email::InvalidMergeRequestError)
+        end
+      end
+
+      context "when we can't find the incoming_email_token" do
+        let(:email_raw) { fixture_file("emails/wrong_incoming_email_token.eml") }
+
+        it "raises an UserNotFoundError" do
+          expect { receiver.execute }.to raise_error(Gitlab::Email::UserNotFoundError)
+        end
+      end
+
+      context "when the subject is blank" do
+        let(:email_raw) { fixture_file("emails/valid_new_merge_request_no_subject.eml") }
+
+        it "raises an InvalidMergeRequestError" do
+          expect { receiver.execute }.to raise_error(Gitlab::Email::InvalidMergeRequestError)
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/email/handler_spec.rb b/spec/lib/gitlab/email/handler_spec.rb
new file mode 100644
index 00000000000..650b01c4df4
--- /dev/null
+++ b/spec/lib/gitlab/email/handler_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe Gitlab::Email::Handler do
+  describe '.for' do
+    it 'picks issue handler if there is not merge request prefix' do
+      expect(described_class.for('email', 'project+key')).to be_an_instance_of(Gitlab::Email::Handler::CreateIssueHandler)
+    end
+
+    it 'picks merge request handler if there is merge request key' do
+      expect(described_class.for('email', 'project+merge-request+key')).to be_an_instance_of(Gitlab::Email::Handler::CreateMergeRequestHandler)
+    end
+
+    it 'returns nil if no handler is found' do
+      expect(described_class.for('email', '')).to be_nil
+    end
+  end
+end