Fix assorted bugs and write spec for importing merge event

lib/gitlab/bitbucket_server_import/importer.rb

@@ -163,6 +163,8 @@ module Gitlab
         target_branch_sha = pull_request.target_branch_sha
         source_branch_sha = project.repository.commit(source_branch_sha)&.sha || source_branch_sha
         target_branch_sha = project.repository.commit(target_branch_sha)&.sha || target_branch_sha
+        author = gitlab_user_id(project, pull_request.author_email) || User.ghost
+
         project.merge_requests.find_by(iid: pull_request.iid)&.destroy
 
         attributes = {
@@ -176,7 +178,7 @@ module Gitlab
           target_branch: Gitlab::Git.ref_name(pull_request.target_branch_name),
           target_branch_sha: target_branch_sha,
           state: pull_request.state,
-          author_id: gitlab_user_id(project, pull_request.author_email),
+          author_id: author.id,
           assignee_id: nil,
           created_at: pull_request.created_at,
           updated_at: pull_request.updated_at
@@ -202,8 +204,8 @@ module Gitlab
       def import_merge_event(merge_request, merge_event)
         committer = merge_event.committer_email
 
-        user = User.ghost
-        user ||= find_user_id(committer) if committer
+        user = find_user_id(committer) if committer
+        user ||= User.ghost
         timestamp = merge_event.merge_timestamp
         metric = MergeRequest::Metrics.find_or_initialize_by(merge_request: merge_request)
         metric.update_attributes(merged_by: user, merged_at: timestamp)

spec/lib/gitlab/bitbucket_server_import/importer_spec.rb

@@ -3,7 +3,7 @@ require 'spec_helper'
 describe Gitlab::BitbucketServerImport::Importer do
   include ImportSpecHelper
 
-  let(:project) { create(:project, import_url: 'http://my-bitbucket') }
+  set(:project) { create(:project, :repository, import_url: 'http://my-bitbucket') }
 
   subject { described_class.new(project) }
 
@@ -32,11 +32,71 @@ describe Gitlab::BitbucketServerImport::Importer do
     end
   end
 
+  # XXX We don't handle pull requests across forks
   describe '#import_pull_requests' do
+    before do
+      allow(subject).to receive(:import_repository)
+      allow(subject).to receive(:delete_temp_branches)
+      allow(subject).to receive(:restore_branches)
+
+      sample = RepoHelpers.sample_compare
+      pull_request = instance_double(
+        BitbucketServer::Representation::PullRequest,
+        iid: 10,
+        source_branch_sha: sample.commits.last,
+        source_branch_name: Gitlab::Git::BRANCH_REF_PREFIX + sample.source_branch,
+        target_branch_sha: sample.commits.first,
+        target_branch_name: Gitlab::Git::BRANCH_REF_PREFIX + sample.target_branch,
+        title: 'This is a title',
+        description: 'This is a test pull request',
+        state: 'merged',
+        author: 'Test Author',
+        author_email: project.owner.email,
+        created_at: Time.now,
+        updated_at: Time.now,
+        merged?: true)
+
+      expect(subject.client).to receive(:pull_requests).and_return([pull_request])
+
+      @merge_event = instance_double(
+        BitbucketServer::Representation::Activity,
+        comment?: false,
+        merge_event?: true,
+        committer_email: project.owner.email,
+        merge_timestamp: Time.now)
+      @inline_comment = instance_double(
+        BitbucketServer::Representation::Activity,
+        comment?: true,
+        merge_event?: false)
+      @pr_comment = instance_double(
+        BitbucketServer::Representation::Activity,
+        comment?: true,
+        merge_event?: false)
+    end
+
+    it 'handles merge event' do
+      expect(subject.client).to receive(:activities).and_return([@merge_event])
+
+      expect { subject.execute }.to change { MergeRequest.count }.by(1)
+
+      merge_request = MergeRequest.first
+      expect(merge_request.metrics.merged_by).to eq(project.owner)
+      expect(merge_request.metrics.merged_at).to eq(@merge_event.merge_timestamp)
+    end
 
+    context 'handles comments' do
+    end
+
+    context 'handles diff comments' do
+    end
+
+    context 'falls back to comments if diff comments' do
+    end
+
+    context 'restores branches of inaccessible SHAs' do
+    end
   end
 
   describe '#delete_temp_branches' do
-
   end
 end