1 files changed, 38 insertions, 0 deletions
diff --git a/spec/lib/declarative_policy_spec.rb b/spec/lib/declarative_policy_spec.rb
new file mode 100644
index 00000000000..5fdb3c27738
--- /dev/null
+++ b/spec/lib/declarative_policy_spec.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe DeclarativePolicy do
+  describe '.class_for' do
+    it 'uses declarative_policy_class if present' do
+      instance = Gitlab::ErrorTracking::ErrorEvent.new
+
+      expect(described_class.class_for(instance)).to eq(ErrorTracking::BasePolicy)
+    end
+
+    it 'infers policy class from name' do
+      instance = PersonalSnippet.new
+
+      expect(described_class.class_for(instance)).to eq(PersonalSnippetPolicy)
+    end
+
+    it 'raises error if not found' do
+      instance = Object.new
+
+      expect { described_class.class_for(instance) }.to raise_error('no policy for Object')
+    end
+
+    context 'when found policy class does not inherit base' do
+      before do
+        stub_const('Foo', Class.new)
+        stub_const('FooPolicy', Class.new)
+      end
+
+      it 'raises error if inferred class does not inherit Base' do
+        instance = Foo.new
+
+        expect { described_class.class_for(instance) }.to raise_error('no policy for Foo')
+      end
+    end
+  end
+end