Add target_id option to TodosMarkAllDone mutation

This allows marking all pending todos of a specific target object as
done. Previously, this mutation always marked all pending todos of the
current user.

Changelog: added

app/graphql/mutations/todos/mark_all_done.rb

@@ -7,14 +7,22 @@ module Mutations
 
       authorize :update_user
 
+      TodoableID = Types::GlobalIDType[Todoable]
+
+      argument :target_id,
+               TodoableID,
+               required: false,
+               description: "Global ID of the to-do item's parent. Issues, merge requests, designs, and epics are supported. " \
+                            "If argument is omitted, all pending to-do items of the current user are marked as done."
+
       field :todos, [::Types::TodoType],
             null: false,
             description: 'Updated to-do items.'
 
-      def resolve
+      def resolve(**args)
         authorize!(current_user)
 
-        updated_ids = mark_all_todos_done
+        updated_ids = mark_all_todos_done(**args)
 
         {
           todos: Todo.id_in(updated_ids),
@@ -24,10 +32,23 @@ module Mutations
 
       private
 
-      def mark_all_todos_done
+      def mark_all_todos_done(**args)
         return [] unless current_user
 
-        todos = TodosFinder.new(current_user).execute
+        finder_params = { state: :pending }
+
+        if args[:target_id].present?
+          target = Gitlab::Graphql::Lazy.force(
+            GitlabSchema.find_by_gid(TodoableID.coerce_isolated_input(args[:target_id]))
+          )
+
+          raise Gitlab::Graphql::Errors::ResourceNotAvailable, "Resource not available: #{args[:target_id]}" if target.nil?
+
+          finder_params[:type] = target.class.name
+          finder_params[:target_id] = target.id
+        end
+
+        todos = TodosFinder.new(current_user, finder_params).execute
 
         TodoService.new.resolve_todos(todos, current_user, resolved_by_action: :api_all_done)
       end

doc/api/graphql/reference/index.md

@@ -4631,6 +4631,7 @@ Input type: `TodosMarkAllDoneInput`
 | Name | Type | Description |
 | ---- | ---- | ----------- |
 | <a id="mutationtodosmarkalldoneclientmutationid"></a>`clientMutationId` | [`String`](#string) | A unique identifier for the client performing the mutation. |
+| <a id="mutationtodosmarkalldonetargetid"></a>`targetId` | [`TodoableID`](#todoableid) | Global ID of the to-do item's parent. Issues, merge requests, designs, and epics are supported. If argument is omitted, all pending to-do items of the current user are marked as done. |
 
 #### Fields
 

spec/requests/api/graphql/mutations/todos/mark_all_done_spec.rb

@@ -50,6 +50,37 @@ RSpec.describe 'Marking all todos done' do
     expect(updated_todo_ids).to contain_exactly(global_id_of(todo1), global_id_of(todo3))
   end
 
+  context 'when target_id is given', :aggregate_failures do
+    let_it_be(:target) { create(:issue, project: project) }
+    let_it_be(:target_todo1) { create(:todo, user: current_user, author: author, state: :pending, target: target) }
+    let_it_be(:target_todo2) { create(:todo, user: current_user, author: author, state: :pending, target: target) }
+
+    let(:input) { { 'targetId' => target.to_global_id.to_s } }
+
+    it 'marks all pending todos for the target as done' do
+      post_graphql_mutation(mutation, current_user: current_user)
+
+      expect(target_todo1.reload.state).to eq('done')
+      expect(target_todo2.reload.state).to eq('done')
+
+      expect(todo1.reload.state).to eq('pending')
+      expect(todo3.reload.state).to eq('pending')
+
+      updated_todo_ids = mutation_response['todos'].map { |todo| todo['id'] }
+      expect(updated_todo_ids).to contain_exactly(global_id_of(target_todo1), global_id_of(target_todo2))
+    end
+
+    context 'when target does not exist' do
+      let(:input) { { 'targetId' => "gid://gitlab/Issue/#{non_existing_record_id}" } }
+
+      it 'returns an error' do
+        post_graphql_mutation(mutation, current_user: current_user)
+
+        expect(graphql_errors).to include(a_hash_including('message' => include('Resource not available')))
+      end
+    end
+  end
+
   it 'behaves as expected if there are no todos for the requesting user' do
     post_graphql_mutation(mutation, current_user: other_user2)