Merge branch 'match-exact-mr-analytics-query' into 'master'

Fix Merge Request analytics query optimization

See merge request gitlab-org/gitlab!53203

app/graphql/resolvers/project_merge_requests_resolver.rb

@@ -22,7 +22,7 @@ module Resolvers
     def only_count_is_selected_with_merged_at_filter?(args)
       return unless lookahead
 
-      argument_names = args.except(:lookahead, :sort, :merged_before, :merged_after).keys
+      argument_names = args.compact.except(:lookahead, :sort, :merged_before, :merged_after).keys
 
       # no extra filtering arguments are provided
       return unless argument_names.empty?
@@ -34,7 +34,7 @@ module Resolvers
       #   totalTimeToMerge
       # }
       allowed_selected_fields = [:count, :total_time_to_merge]
-      selected_fields = lookahead.selections.map(&:field).map(&:original_name)
+      selected_fields = lookahead.selections.map(&:field).map(&:original_name) - [:__typename] # ignore __typename meta field
 
       # only the allowed_selected_fields are present
       (selected_fields - allowed_selected_fields).empty?

spec/requests/api/graphql/project/merge_requests_spec.rb

@@ -407,10 +407,12 @@ RSpec.describe 'getting merge request listings nested in a project' do
       end
 
       let(:query) do
+        # Note: __typename meta field is always requested by the FE
         graphql_query_for(:project, { full_path: project.full_path },
         <<~QUERY
-        mergeRequests(mergedAfter: "2020-01-01", mergedBefore: "2020-01-05", first: 0) {
+        mergeRequests(mergedAfter: "2020-01-01", mergedBefore: "2020-01-05", first: 0, sourceBranches: null, labels: null) {
           count
+          __typename
         }
         QUERY
         )