Fix validation method for Gitlab::GithubImport::PullRequestFormatter

lib/gitlab/github_import/branch_formatter.rb

@@ -15,6 +15,10 @@ module Gitlab
         repo.present?
       end
+      def valid?
+        repo.present?
+      end
+
       private
       def short_id

lib/gitlab/github_import/pull_request_formatter.rb

@@ -29,7 +29,7 @@ module Gitlab
       end
       def valid?
-        !cross_project?
+        source_branch.valid? && target_branch.valid? && !cross_project?
       end
       def source_branch
@@ -65,8 +65,7 @@ module Gitlab
       end
       def cross_project?
-        source_branch_repo.present? && target_branch_repo.present? &&
-          source_branch_repo.id != target_branch_repo.id
+        source_branch_repo.id != target_branch_repo.id
       end
       def description

spec/lib/gitlab/github_import/branch_formatter_spec.rb

@@ -54,4 +54,18 @@ describe Gitlab::GithubImport::BranchFormatter, lib: true do
       expect(branch.sha).to eq '2e5d3239642f9161dcbbc4b70a211a68e5e45e2b'
     end
   end
+
+  describe '#valid?' do
+    it 'returns true when repository exists' do
+      branch = described_class.new(project, double(raw))
+
+      expect(branch.valid?).to eq true
+    end
+
+    it 'returns false when repository does not exist' do
+      branch = described_class.new(project, double(raw.merge(repo: nil)))
+
+      expect(branch.valid?).to eq false
+    end
+  end
 end

spec/lib/gitlab/github_import/pull_request_formatter_spec.rb

@@ -173,7 +173,7 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
     end
     context 'when source repo is a fork' do
-      let(:source_repo) { double(id: 2, fork: true) }
+      let(:source_repo) { double(id: 2) }
       let(:raw_data) { double(base_data) }
       it 'returns false' do
@@ -182,7 +182,7 @@ describe Gitlab::GithubImport::PullRequestFormatter, lib: true do
     end
     context 'when target repo is a fork' do
-      let(:target_repo) { double(id: 2, fork: true) }
+      let(:target_repo) { double(id: 2) }
       let(:raw_data) { double(base_data) }
       it 'returns false' do