Add GraphQL mutation to restore a Todo

Also add specs

app/graphql/mutations/todos/restore.rb

+# frozen_string_literal: true
+
+module Mutations
+  module Todos
+    class Restore < ::Mutations::Todos::Base
+      graphql_name 'TodoRestore'
+
+      authorize :update_todo
+
+      argument :id,
+               GraphQL::ID_TYPE,
+               required: true,
+               description: 'The global id of the todo to restore'
+
+      field :todo, Types::TodoType,
+            null: false,
+            description: 'The requested todo'
+
+      def resolve(id:)
+        todo = authorized_find!(id: id)
+        restore(todo.id) if todo.done?
+
+        {
+          todo: todo.reset,
+          errors: errors_on_object(todo)
+        }
+      end
+
+      private
+
+      def restore(id)
+        TodoService.new.mark_todos_as_pending_by_ids([id], current_user)
+      end
+    end
+  end
+end

app/graphql/types/mutation_type.rb

@@ -21,6 +21,7 @@ module Types
     mount_mutation Mutations::Notes::Update
     mount_mutation Mutations::Notes::Destroy
     mount_mutation Mutations::Todos::MarkDone
+    mount_mutation Mutations::Todos::Restore
   end
 end
 

changelogs/unreleased/31914-graphql-todo-restore-pd.yml

+---
+title: Add GraphQL mutation to restore a Todo
+merge_request: 20261
+author:
+type: added

doc/api/graphql/reference/gitlab_schema.graphql

@@ -3519,6 +3519,7 @@ type Mutation {
   mergeRequestSetWip(input: MergeRequestSetWipInput!): MergeRequestSetWipPayload
   removeAwardEmoji(input: RemoveAwardEmojiInput!): RemoveAwardEmojiPayload
   todoMarkDone(input: TodoMarkDoneInput!): TodoMarkDonePayload
+  todoRestore(input: TodoRestoreInput!): TodoRestorePayload
   toggleAwardEmoji(input: ToggleAwardEmojiInput!): ToggleAwardEmojiPayload
   updateEpic(input: UpdateEpicInput!): UpdateEpicPayload
   updateNote(input: UpdateNoteInput!): UpdateNotePayload
@@ -4992,6 +4993,41 @@ type TodoMarkDonePayload {
   todo: Todo!
 }
 
+"""
+Autogenerated input type of TodoRestore
+"""
+input TodoRestoreInput {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  The global id of the todo to restore
+  """
+  id: ID!
+}
+
+"""
+Autogenerated return type of TodoRestore
+"""
+type TodoRestorePayload {
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Reasons why the mutation failed.
+  """
+  errors: [String!]!
+
+  """
+  The requested todo
+  """
+  todo: Todo!
+}
+
 enum TodoStateEnum {
   done
   pending

doc/api/graphql/reference/gitlab_schema.json

@@ -14328,6 +14328,33 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "todoRestore",
+              "description": null,
+              "args": [
+                {
+                  "name": "input",
+                  "description": null,
+                  "type": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "INPUT_OBJECT",
+                      "name": "TodoRestoreInput",
+                      "ofType": null
+                    }
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "TodoRestorePayload",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "toggleAwardEmoji",
               "description": null,
@@ -16692,6 +16719,112 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "OBJECT",
+          "name": "TodoRestorePayload",
+          "description": "Autogenerated return type of TodoRestore",
+          "fields": [
+            {
+              "name": "clientMutationId",
+              "description": "A unique identifier for the client performing the mutation.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "errors",
+              "description": "Reasons why the mutation failed.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "LIST",
+                  "name": null,
+                  "ofType": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "SCALAR",
+                      "name": "String",
+                      "ofType": null
+                    }
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "todo",
+              "description": "The requested todo",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "Todo",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "INPUT_OBJECT",
+          "name": "TodoRestoreInput",
+          "description": "Autogenerated input type of TodoRestore",
+          "fields": null,
+          "inputFields": [
+            {
+              "name": "id",
+              "description": "The global id of the todo to restore",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "ID",
+                  "ofType": null
+                }
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "clientMutationId",
+              "description": "A unique identifier for the client performing the mutation.",
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "defaultValue": null
+            }
+          ],
+          "interfaces": null,
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "DesignManagementUploadPayload",

doc/api/graphql/reference/index.md

@@ -777,6 +777,14 @@ The API can be explored interactively using the [GraphiQL IDE](../index.md#graph
 | `errors` | String! => Array | Reasons why the mutation failed. |
 | `todo` | Todo! | The requested todo |
 
+### TodoRestorePayload
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Reasons why the mutation failed. |
+| `todo` | Todo! | The requested todo |
+
 ### ToggleAwardEmojiPayload
 
 | Name  | Type  | Description |

spec/graphql/mutations/todos/restore_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Mutations::Todos::Restore do
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:author) { create(:user) }
+  let_it_be(:other_user) { create(:user) }
+
+  let_it_be(:todo1) { create(:todo, user: current_user, author: author, state: :done) }
+  let_it_be(:todo2) { create(:todo, user: current_user, author: author, state: :pending) }
+
+  let_it_be(:other_user_todo) { create(:todo, user: other_user, author: author, state: :done) }
+
+  let(:mutation) { described_class.new(object: nil, context: { current_user: current_user }) }
+
+  describe '#resolve' do
+    it 'restores a single todo' do
+      result = restore_mutation(todo1)
+
+      expect(todo1.reload.state).to eq('pending')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+
+      todo = result[:todo]
+      expect(todo.id).to eq(todo1.id)
+      expect(todo.state).to eq('pending')
+    end
+
+    it 'handles a todo which is already pending as expected' do
+      result = restore_mutation(todo2)
+
+      expect(todo1.reload.state).to eq('done')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+
+      todo = result[:todo]
+      expect(todo.id).to eq(todo2.id)
+      expect(todo.state).to eq('pending')
+    end
+
+    it 'ignores requests for todos which do not belong to the current user' do
+      expect { restore_mutation(other_user_todo) }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+
+      expect(todo1.reload.state).to eq('done')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+    end
+
+    it 'ignores invalid GIDs' do
+      expect { mutation.resolve(id: 'invalid_gid') }.to raise_error(Gitlab::Graphql::Errors::ArgumentError)
+
+      expect(todo1.reload.state).to eq('done')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+    end
+  end
+
+  def restore_mutation(todo)
+    mutation.resolve(id: global_id_of(todo))
+  end
+
+  def global_id_of(todo)
+    todo.to_global_id.to_s
+  end
+end

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

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Restoring Todos' do
+  include GraphqlHelpers
+
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:author) { create(:user) }
+  let_it_be(:other_user) { create(:user) }
+
+  let_it_be(:todo1) { create(:todo, user: current_user, author: author, state: :done) }
+  let_it_be(:todo2) { create(:todo, user: current_user, author: author, state: :pending) }
+
+  let_it_be(:other_user_todo) { create(:todo, user: other_user, author: author, state: :done) }
+
+  let(:input) { { id: todo1.to_global_id.to_s } }
+
+  let(:mutation) do
+    graphql_mutation(:todo_restore, input,
+                     <<-QL.strip_heredoc
+                       clientMutationId
+                       errors
+                       todo {
+                         id
+                         state
+                       }
+                     QL
+    )
+  end
+
+  def mutation_response
+    graphql_mutation_response(:todo_restore)
+  end
+
+  it 'restores a single todo' do
+    post_graphql_mutation(mutation, current_user: current_user)
+
+    expect(todo1.reload.state).to eq('pending')
+    expect(todo2.reload.state).to eq('pending')
+    expect(other_user_todo.reload.state).to eq('done')
+
+    todo = mutation_response['todo']
+    expect(todo['id']).to eq(todo1.to_global_id.to_s)
+    expect(todo['state']).to eq('pending')
+  end
+
+  context 'when todo is already marked pending' do
+    let(:input) { { id: todo2.to_global_id.to_s } }
+
+    it 'has the expected response' do
+      post_graphql_mutation(mutation, current_user: current_user)
+
+      expect(todo1.reload.state).to eq('done')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+
+      todo = mutation_response['todo']
+      expect(todo['id']).to eq(todo2.to_global_id.to_s)
+      expect(todo['state']).to eq('pending')
+    end
+  end
+
+  context 'when todo does not belong to requesting user' do
+    let(:input) { { id: other_user_todo.to_global_id.to_s } }
+    let(:access_error) { 'The resource that you are attempting to access does not exist or you don\'t have permission to perform this action' }
+
+    it 'contains the expected error' do
+      post_graphql_mutation(mutation, current_user: current_user)
+
+      errors = json_response['errors']
+      expect(errors).not_to be_blank
+      expect(errors.first['message']).to eq(access_error)
+
+      expect(todo1.reload.state).to eq('done')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+    end
+  end
+
+  context 'when using an invalid gid' do
+    let(:input) { { id: 'invalid_gid' } }
+    let(:invalid_gid_error) { 'invalid_gid is not a valid GitLab id.' }
+
+    it 'contains the expected error' do
+      post_graphql_mutation(mutation, current_user: current_user)
+
+      errors = json_response['errors']
+      expect(errors).not_to be_blank
+      expect(errors.first['message']).to eq(invalid_gid_error)
+
+      expect(todo1.reload.state).to eq('done')
+      expect(todo2.reload.state).to eq('pending')
+      expect(other_user_todo.reload.state).to eq('done')
+    end
+  end
+end