RFC: Resolver for inclusion of related models

acceptance/repository-mongodb/src/__tests__/mongodb.datasource.ts

@@ -16,4 +16,8 @@ export const MONGODB_CONFIG: DataSourceOptions = {
 
 export const MONGODB_FEATURES: Partial<CrudFeatures> = {
   idType: 'string',
+
+  // TODO: we should run the test suite against two connector configurations:
+  // - one with "strictObjectID" set to true,
+  // - the other with "strictObjectID" turned off (the default).
 };

examples/todo-list/src/__tests__/integration/todo-list.repository.integration.ts

@@ -7,6 +7,7 @@ import {
 import {
   givenEmptyDatabase,
   givenTodoInstance,
+  givenTodoListImageInstance,
   givenTodoListInstance,
   testdb,
 } from '../helpers';
@@ -23,6 +24,10 @@ describe('TodoListRepository', () => {
       async () => todoListImageRepo,
     );
     todoRepo = new TodoRepository(testdb, async () => todoListRepo);
+    todoListImageRepo = new TodoListImageRepository(
+      testdb,
+      async () => todoListRepo,
+    );
   });
 
   beforeEach(givenEmptyDatabase);
@@ -43,6 +48,21 @@ describe('TodoListRepository', () => {
     ]);
   });
 
+  it('includes Todos in findOne method result', async () => {
+    const list = await givenTodoListInstance(todoListRepo);
+    const todo = await givenTodoInstance(todoRepo, {todoListId: list.id});
+
+    const response = await todoListRepo.findOne({
+      where: {id: list.id},
+      include: [{relation: 'todos'}],
+    });
+
+    expect(toJSON(response)).to.deepEqual({
+      ...toJSON(list),
+      todos: [toJSON(todo)],
+    });
+  });
+
   it('includes Todos in findById result', async () => {
     const list = await givenTodoListInstance(todoListRepo);
     const todo = await givenTodoInstance(todoRepo, {todoListId: list.id});
@@ -56,4 +76,22 @@ describe('TodoListRepository', () => {
       todos: [toJSON(todo)],
     });
   });
+
+  it('includes TodoListImage in find method result', async () => {
+    const list = await givenTodoListInstance(todoListRepo);
+    const image = await givenTodoListImageInstance(todoListImageRepo, {
+      todoListId: list.id,
+    });
+
+    const response = await todoListRepo.find({
+      include: [{relation: 'image'}],
+    });
+
+    expect(toJSON(response)).to.deepEqual([
+      {
+        ...toJSON(list),
+        image: toJSON(image),
+      },
+    ]);
+  });
 });

examples/todo-list/src/__tests__/integration/todo.repository.integration.ts

@@ -56,4 +56,19 @@ describe('TodoRepository', () => {
       todoList: toJSON(list),
     });
   });
+
+  it('includes TodoList in findOne result', async () => {
+    const list = await givenTodoListInstance(todoListRepo, {});
+    const todo = await givenTodoInstance(todoRepo, {todoListId: list.id});
+
+    const response = await todoRepo.findOne({
+      where: {id: todo.id},
+      include: [{relation: 'todoList'}],
+    });
+
+    expect(toJSON(response)).to.deepEqual({
+      ...toJSON(todo),
+      todoList: toJSON(list),
+    });
+  });
 });

examples/todo-list/src/repositories/todo-list-image.repository.ts

@@ -7,17 +7,10 @@ import {Getter, inject} from '@loopback/core';
 import {
   BelongsToAccessor,
   DefaultCrudRepository,
-  Filter,
-  Options,
   repository,
 } from '@loopback/repository';
 import {DbDataSource} from '../datasources';
-import {
-  TodoList,
-  TodoListImage,
-  TodoListImageRelations,
-  TodoListImageWithRelations,
-} from '../models';
+import {TodoList, TodoListImage, TodoListImageRelations} from '../models';
 import {TodoListRepository} from './todo-list.repository';
 
 export class TodoListImageRepository extends DefaultCrudRepository<
@@ -39,55 +32,6 @@ export class TodoListImageRepository extends DefaultCrudRepository<
       'todoList',
       todoListRepositoryGetter,
     );
-  }
-
-  async find(
-    filter?: Filter<TodoListImage>,
-    options?: Options,
-  ): Promise<TodoListImageWithRelations[]> {
-    // Prevent juggler for applying "include" filter
-    // Juggler is not aware of LB4 relations
-    const include = filter && filter.include;
-    filter = {...filter, include: undefined};
-
-    const result = await super.find(filter, options);
-
-    // poor-mans inclusion resolver, this should be handled by DefaultCrudRepo
-    // and use `inq` operator to fetch related todo-lists in fewer DB queries
-    // this is a temporary implementation, please see
-    // https://github.com/strongloop/loopback-next/issues/3195
-    if (include && include.length && include[0].relation === 'todoList') {
-      await Promise.all(
-        result.map(async r => {
-          // eslint-disable-next-line require-atomic-updates
-          r.todoList = await this.todoList(r.id);
-        }),
-      );
-    }
-
-    return result;
-  }
-
-  async findById(
-    id: typeof TodoListImage.prototype.id,
-    filter?: Filter<TodoListImage>,
-    options?: Options,
-  ): Promise<TodoListImageWithRelations> {
-    // Prevent juggler for applying "include" filter
-    // Juggler is not aware of LB4 relations
-    const include = filter && filter.include;
-    filter = {...filter, include: undefined};
-
-    const result = await super.findById(id, filter, options);
-
-    // poor-mans inclusion resolver, this should be handled by DefaultCrudRepo
-    // and use `inq` operator to fetch related todo-lists in fewer DB queries
-    // this is a temporary implementation, please see
-    // https://github.com/strongloop/loopback-next/issues/3195
-    if (include && include.length && include[0].relation === 'todoList') {
-      result.todoList = await this.todoList(result.id);
-    }
-
-    return result;
+    this.registerInclusion('todoList', this.todoList.inclusionResolver);
   }
 }

examples/todo-list/src/repositories/todo-list.repository.ts

@@ -6,20 +6,12 @@
 import {Getter, inject} from '@loopback/core';
 import {
   DefaultCrudRepository,
-  Filter,
   HasManyRepositoryFactory,
   HasOneRepositoryFactory,
   juggler,
-  Options,
   repository,
 } from '@loopback/repository';
-import {
-  Todo,
-  TodoList,
-  TodoListImage,
-  TodoListRelations,
-  TodoListWithRelations,
-} from '../models';
+import {Todo, TodoList, TodoListImage, TodoListRelations} from '../models';
 import {TodoListImageRepository} from './todo-list-image.repository';
 import {TodoRepository} from './todo.repository';
 
@@ -45,66 +37,21 @@ export class TodoListRepository extends DefaultCrudRepository<
     protected todoListImageRepositoryGetter: Getter<TodoListImageRepository>,
   ) {
     super(TodoList, dataSource);
+
     this.todos = this.createHasManyRepositoryFactoryFor(
       'todos',
       todoRepositoryGetter,
     );
+    this.registerInclusion('todos', this.todos.inclusionResolver);
+
     this.image = this.createHasOneRepositoryFactoryFor(
       'image',
       todoListImageRepositoryGetter,
     );
+    this.registerInclusion('image', this.image.inclusionResolver);
   }
 
   public findByTitle(title: string) {
     return this.findOne({where: {title}});
   }
-
-  async find(
-    filter?: Filter<TodoList>,
-    options?: Options,
-  ): Promise<TodoListWithRelations[]> {
-    // Prevent juggler for applying "include" filter
-    // Juggler is not aware of LB4 relations
-    const include = filter && filter.include;
-    filter = {...filter, include: undefined};
-    const result = await super.find(filter, options);
-
-    // poor-mans inclusion resolver, this should be handled by DefaultCrudRepo
-    // and use `inq` operator to fetch related todos in fewer DB queries
-    // this is a temporary implementation, please see
-    // https://github.com/strongloop/loopback-next/issues/3195
-    if (include && include.length && include[0].relation === 'todos') {
-      await Promise.all(
-        result.map(async r => {
-          // eslint-disable-next-line require-atomic-updates
-          r.todos = await this.todos(r.id).find();
-        }),
-      );
-    }
-
-    return result;
-  }
-
-  async findById(
-    id: typeof TodoList.prototype.id,
-    filter?: Filter<TodoList>,
-    options?: Options,
-  ): Promise<TodoListWithRelations> {
-    // Prevent juggler for applying "include" filter
-    // Juggler is not aware of LB4 relations
-    const include = filter && filter.include;
-    filter = {...filter, include: undefined};
-
-    const result = await super.findById(id, filter, options);
-
-    // poor-mans inclusion resolver, this should be handled by DefaultCrudRepo
-    // and use `inq` operator to fetch related todos in fewer DB queries
-    // this is a temporary implementation, please see
-    // https://github.com/strongloop/loopback-next/issues/3195
-    if (include && include.length && include[0].relation === 'todos') {
-      result.todos = await this.todos(result.id).find();
-    }
-
-    return result;
-  }
 }

examples/todo-list/src/repositories/todo.repository.ts

@@ -7,12 +7,10 @@ import {Getter, inject} from '@loopback/core';
 import {
   BelongsToAccessor,
   DefaultCrudRepository,
-  Filter,
   juggler,
-  Options,
   repository,
 } from '@loopback/repository';
-import {Todo, TodoList, TodoRelations, TodoWithRelations} from '../models';
+import {Todo, TodoList, TodoRelations} from '../models';
 import {TodoListRepository} from './todo-list.repository';
 
 export class TodoRepository extends DefaultCrudRepository<
@@ -36,55 +34,6 @@ export class TodoRepository extends DefaultCrudRepository<
       'todoList',
       todoListRepositoryGetter,
     );
-  }
-
-  async find(
-    filter?: Filter<Todo>,
-    options?: Options,
-  ): Promise<TodoWithRelations[]> {
-    // Prevent juggler for applying "include" filter
-    // Juggler is not aware of LB4 relations
-    const include = filter && filter.include;
-    filter = {...filter, include: undefined};
-
-    const result = await super.find(filter, options);
-
-    // poor-mans inclusion resolver, this should be handled by DefaultCrudRepo
-    // and use `inq` operator to fetch related todo-lists in fewer DB queries
-    // this is a temporary implementation, please see
-    // https://github.com/strongloop/loopback-next/issues/3195
-    if (include && include.length && include[0].relation === 'todoList') {
-      await Promise.all(
-        result.map(async r => {
-          // eslint-disable-next-line require-atomic-updates
-          r.todoList = await this.todoList(r.id);
-        }),
-      );
-    }
-
-    return result;
-  }
-
-  async findById(
-    id: typeof Todo.prototype.id,
-    filter?: Filter<Todo>,
-    options?: Options,
-  ): Promise<TodoWithRelations> {
-    // Prevent juggler for applying "include" filter
-    // Juggler is not aware of LB4 relations
-    const include = filter && filter.include;
-    filter = {...filter, include: undefined};
-
-    const result = await super.findById(id, filter, options);
-
-    // poor-mans inclusion resolver, this should be handled by DefaultCrudRepo
-    // and use `inq` operator to fetch related todo-lists in fewer DB queries
-    // this is a temporary implementation, please see
-    // https://github.com/strongloop/loopback-next/issues/3195
-    if (include && include.length && include[0].relation === 'todoList') {
-      result.todoList = await this.todoList(result.id);
-    }
-
-    return result;
+    this.registerInclusion('todoList', this.todoList.inclusionResolver);
   }
 }

packages/repository-tests/src/crud-test-suite.ts

@@ -31,6 +31,7 @@ export function crudRepositoryTestSuite(
   const features: CrudFeatures = {
     idType: 'string',
     freeFormProperties: true,
+    inclusionResolvers: true,
     ...partialFeatures,
   };
 
@@ -70,7 +71,7 @@ export function crudRepositoryTestSuite(
           suite.name,
           dataSourceOptions,
           'class ' + repositoryClass.name,
-          partialFeatures,
+          features,
         );
         suite(dataSourceOptions, repositoryClass, features);
       }