Add argument iids to IssuesResolver

app/graphql/resolvers/issues_resolver.rb

@@ -4,6 +4,10 @@ module Resolvers
   class IssuesResolver < BaseResolver
     extend ActiveSupport::Concern
 
+    argument :iids, [GraphQL::ID_TYPE],
+              required: false,
+              description: 'The list of IIDs of issues, e.g., [1, 2]'
+
     argument :search, GraphQL::STRING_TYPE,
               required: false
     argument :sort, Types::Sort,

changelogs/unreleased/57063-implement-new-arguments-iid-for-issuesresolver-in-graphql.yml

+---
+title: Add argument iids for issues in GraphQL
+merge_request: 24802
+author:
+type: added

spec/graphql/resolvers/issues_resolver_spec.rb

@@ -32,6 +32,26 @@ describe Resolvers::IssuesResolver do
 
       expect(resolve_issues).to contain_exactly(issue, issue2)
     end
+
+    it 'finds a specific issue with iids' do
+      expect(resolve_issues(iids: issue.iid)).to contain_exactly(issue)
+    end
+
+    it 'finds multiple issues with iids' do
+      expect(resolve_issues(iids: [issue.iid, issue2.iid]))
+        .to contain_exactly(issue, issue2)
+    end
+
+    it 'finds only the issues within the project we are looking at' do
+      another_project = create(:project)
+      iids = [issue, issue2].map(&:iid)
+
+      iids.each do |iid|
+        create(:issue, project: another_project, iid: iid)
+      end
+
+      expect(resolve_issues(iids: iids)).to contain_exactly(issue, issue2)
+    end
   end
 
   def resolve_issues(args = {}, context = { current_user: current_user })