Add tests for BaseResolver and update accordingly

spec/graphql/resolvers/base_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Resolvers::BaseResolver do
+  include GraphqlHelpers
+
+  let(:resolver) do
+    Class.new(described_class) do
+      def resolve(**args)
+        [args, args]
+      end
+    end
+  end
+
+  describe '.single' do
+    it 'returns a subclass from the resolver' do
+      expect(resolver.single.superclass).to eq(resolver)
+    end
+
+    it 'returns the same subclass every time' do
+      expect(resolver.single.object_id).to eq(resolver.single.object_id)
+    end
+
+    it 'returns a resolver that gives the first result from the original resolver' do
+      result = resolve(resolver.single, args: { test: 1 })
+
+      expect(result).to eq(test: 1)
+    end
+  end
+end

spec/graphql/resolvers/merge_requests_resolver_spec.rb

@@ -16,9 +16,17 @@ describe Resolvers::MergeRequestsResolver do
   let(:other_iid) { other_merge_request.iid }
 
   describe '#resolve' do
-    it 'batch-resolves merge requests by target project full path and IID' do
+    it 'batch-resolves by target project full path and individual IID' do
       result = batch(max_queries: 2) do
-        resolve_mr(project, iid_1) + resolve_mr(project, iid_2)
+        resolve_mr(project, iid: iid_1) + resolve_mr(project, iid: iid_2)
+      end
+
+      expect(result).to contain_exactly(merge_request_1, merge_request_2)
+    end
+
+    it 'batch-resolves by target project full path and IIDS' do
+      result = batch(max_queries: 2) do
+        resolve_mr(project, iids: [iid_1, iid_2])
       end
 
       expect(result).to contain_exactly(merge_request_1, merge_request_2)
@@ -26,22 +34,28 @@ describe Resolvers::MergeRequestsResolver do
 
     it 'can batch-resolve merge requests from different projects' do
       result = batch(max_queries: 3) do
-        resolve_mr(project, iid_1) +
-          resolve_mr(project, iid_2) +
-          resolve_mr(other_project, other_iid)
+        resolve_mr(project, iid: iid_1) +
+          resolve_mr(project, iid: iid_2) +
+          resolve_mr(other_project, iid: other_iid)
       end
 
       expect(result).to contain_exactly(merge_request_1, merge_request_2, other_merge_request)
     end
 
-    it 'resolves an unknown iid to nil' do
-      result = batch { resolve_mr(project, -1) }
+    it 'resolves an unknown iid to be empty' do
+      result = batch { resolve_mr(project, iid: -1) }
+
+      expect(result).to be_empty
+    end
+
+    it 'resolves empty iids to be empty' do
+      result = batch { resolve_mr(project, iids: []) }
 
       expect(result).to be_empty
     end
   end
 
-  def resolve_mr(project, iid)
-    resolve(described_class, obj: project, args: { iid: iid })
+  def resolve_mr(project, args)
+    resolve(described_class, obj: project, args: args)
   end
 end

spec/graphql/types/project_type_spec.rb

@@ -6,12 +6,17 @@ describe GitlabSchema.types['Project'] do
   it { expect(described_class.graphql_name).to eq('Project') }
 
   describe 'nested merge request' do
+    it { expect(described_class).to have_graphql_field(:merge_requests) }
     it { expect(described_class).to have_graphql_field(:merge_request) }
 
     it 'authorizes the merge request' do
       expect(described_class.fields['mergeRequest'])
         .to require_graphql_authorizations(:read_merge_request)
     end
+
+    it 'authorizes the merge requests' do
+      skip
+    end
   end
 
   describe 'nested issues' do