Merge branch '221174-graphql-pagination-bug' into 'master'

Graphql - fix pagination bug due to ms precision

See merge request gitlab-org/gitlab!34352

changelogs/unreleased/221174-graphql-pagination-bug.yml

+---
+title: GraphQL - properly handle pagination of millisecond-precision timestamps
+merge_request: 34352
+author:
+type: fixed

lib/gitlab/graphql/pagination/keyset/connection.rb

@@ -194,7 +194,12 @@ module Gitlab
 
             order_list.each do |field|
               field_name = field.attribute_name
-              ordering[field_name] = node[field_name].to_s
+              field_value = node[field_name]
+              ordering[field_name] = if field_value.is_a?(Time)
+                                       field_value.strftime('%Y-%m-%d %H:%M:%S.%N %Z')
+                                     else
+                                       field_value.to_s
+                                     end
             end
 
             encode(ordering.to_json)

spec/lib/gitlab/graphql/pagination/keyset/connection_spec.rb

@@ -33,7 +33,7 @@ describe Gitlab::Graphql::Pagination::Keyset::Connection do
       let(:nodes) { Project.order(:updated_at) }
 
       it 'returns the encoded value of the order' do
-        expect(decoded_cursor(cursor)).to include('updated_at' => project.updated_at.to_s)
+        expect(decoded_cursor(cursor)).to include('updated_at' => project.updated_at.strftime('%Y-%m-%d %H:%M:%S.%N %Z'))
       end
 
       it 'includes the :id even when not specified in the order' do
@@ -45,7 +45,7 @@ describe Gitlab::Graphql::Pagination::Keyset::Connection do
       let(:nodes) { Project.order(:updated_at).order(:created_at) }
 
       it 'returns the encoded value of the order' do
-        expect(decoded_cursor(cursor)).to include('updated_at' => project.updated_at.to_s)
+        expect(decoded_cursor(cursor)).to include('updated_at' => project.updated_at.strftime('%Y-%m-%d %H:%M:%S.%N %Z'))
       end
     end
 
@@ -53,7 +53,7 @@ describe Gitlab::Graphql::Pagination::Keyset::Connection do
       let(:nodes) { Project.order(Arel.sql('projects.updated_at IS NULL')).order(:updated_at).order(:id) }
 
       it 'returns the encoded value of the order' do
-        expect(decoded_cursor(cursor)).to include('updated_at' => project.updated_at.to_s)
+        expect(decoded_cursor(cursor)).to include('updated_at' => project.updated_at.strftime('%Y-%m-%d %H:%M:%S.%N %Z'))
       end
     end
   end

spec/requests/api/graphql_spec.rb

@@ -187,4 +187,62 @@ describe 'GraphQL' do
       end
     end
   end
+
+  describe 'keyset pagination' do
+    let_it_be(:project) { create(:project, :public) }
+    let_it_be(:issues) { create_list(:issue, 10, project: project, created_at: Time.now.change(usec: 200)) }
+
+    let(:page_size) { 6 }
+    let(:issues_edges) { %w(data project issues edges) }
+    let(:end_cursor) { %w(data project issues pageInfo endCursor) }
+    let(:query) do
+      <<~GRAPHQL
+        query project($fullPath: ID!, $first: Int, $after: String) {
+            project(fullPath: $fullPath) {
+              issues(first: $first, after: $after) {
+                edges { node { iid } }
+                pageInfo { endCursor }
+              }
+            }
+        }
+      GRAPHQL
+    end
+
+    # TODO: Switch this to use `post_graphql`
+    # This is not performing an actual GraphQL request because the
+    # variables end up being strings when passed through the `post_graphql`
+    # helper.
+    #
+    # https://gitlab.com/gitlab-org/gitlab/-/issues/222432
+    def execute_query(after: nil)
+      GitlabSchema.execute(
+        query,
+        context: { current_user: nil },
+        variables: {
+          fullPath: project.full_path,
+          first: page_size,
+          after: after
+        }
+      )
+    end
+
+    it 'paginates datetimes correctly when they have millisecond data' do
+      # let's make sure we're actually querying a timestamp, just in case
+      expect(Gitlab::Graphql::Pagination::Keyset::QueryBuilder)
+        .to receive(:new).with(anything, anything, hash_including('created_at'), anything).and_call_original
+
+      first_page = execute_query
+      edges = first_page.dig(*issues_edges)
+      cursor = first_page.dig(*end_cursor)
+
+      expect(edges.count).to eq(6)
+      expect(edges.last['node']['iid']).to eq(issues[4].iid.to_s)
+
+      second_page = execute_query(after: cursor)
+      edges = second_page.dig(*issues_edges)
+
+      expect(edges.count).to eq(4)
+      expect(edges.last['node']['iid']).to eq(issues[0].iid.to_s)
+    end
+  end
 end