1 files changed, 49 insertions, 0 deletions
diff --git a/spec/graphql/gitlab_schema_spec.rb b/spec/graphql/gitlab_schema_spec.rb
index 5d6aa863994..4db12643069 100644
--- a/spec/graphql/gitlab_schema_spec.rb
+++ b/spec/graphql/gitlab_schema_spec.rb
@@ -212,6 +212,55 @@ RSpec.describe GitlabSchema do
     end
   end
 
+  describe '.parse_gid' do
+    let_it_be(:global_id) { 'gid://gitlab/TestOne/2147483647' }
+
+    before do
+      test_base = Class.new
+      test_one = Class.new(test_base)
+      test_two = Class.new(test_base)
+
+      stub_const('TestBase', test_base)
+      stub_const('TestOne', test_one)
+      stub_const('TestTwo', test_two)
+    end
+
+    it 'parses the gid' do
+      gid = described_class.parse_gid(global_id)
+
+      expect(gid.model_id).to eq '2147483647'
+      expect(gid.model_class).to eq TestOne
+    end
+
+    context 'when gid is malformed' do
+      let_it_be(:global_id) { 'malformed://gitlab/TestOne/2147483647' }
+
+      it 'raises an error' do
+        expect { described_class.parse_gid(global_id) }
+          .to raise_error(Gitlab::Graphql::Errors::ArgumentError, "#{global_id} is not a valid GitLab ID.")
+      end
+    end
+
+    context 'when using expected_type' do
+      it 'accepts a single type' do
+        gid = described_class.parse_gid(global_id, expected_type: TestOne)
+
+        expect(gid.model_class).to eq TestOne
+      end
+
+      it 'accepts an ancestor type' do
+        gid = described_class.parse_gid(global_id, expected_type: TestBase)
+
+        expect(gid.model_class).to eq TestOne
+      end
+
+      it 'rejects an unknown type' do
+        expect { described_class.parse_gid(global_id, expected_type: TestTwo) }
+          .to raise_error(Gitlab::Graphql::Errors::ArgumentError, "#{global_id} is not a valid ID for TestTwo.")
+      end
+    end
+  end
+
   def field_instrumenters
     described_class.instrumenters[:field] + described_class.instrumenters[:field_after_built_ins]
   end