feat(repository): implement inclusion resolver helpers

packages/repository/package.json

@@ -22,7 +22,9 @@
     "@loopback/eslint-config": "^4.1.0",
     "@loopback/testlab": "^1.8.1",
     "@types/lodash": "^4.14.138",
-    "@types/node": "^10.14.18"
+    "@types/node": "^10.14.18",
+    "@types/bson": "^4.0.0",
+    "bson": "1.0.6"
   },
   "dependencies": {
     "@loopback/context": "^1.23.0",

packages/repository/src/__tests__/unit/repositories/relations-helpers/build-lookup-map.unit.ts

@@ -0,0 +1,78 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/repository
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+import {expect} from '@loopback/testlab';
+import {buildLookupMap, reduceAsArray, reduceAsSingleItem} from '../../../..';
+import {
+  Category,
+  Product,
+  createProduct,
+  createCategory,
+} from './relations-helpers-fixtures';
+
+describe('buildLookupMap', () => {
+  describe('get the result of using reduceAsArray strategy for hasMany relation', () => {
+    it('returns multiple instances in an array', () => {
+      const pen = createProduct({name: 'pen', categoryId: 1});
+      const pencil = createProduct({name: 'pencil', categoryId: 1});
+
+      const result = buildLookupMap<unknown, Product, Category[]>(
+        [pen, pencil],
+        'categoryId',
+        reduceAsArray,
+      );
+      const expected = new Map<Number, Array<Product>>();
+      expected.set(1, [pen, pencil]);
+      expect(result).to.eql(expected);
+    });
+
+    it('return instances in multiple arrays', () => {
+      const pen = createProduct({name: 'pen', categoryId: 1});
+      const pencil = createProduct({name: 'pencil', categoryId: 1});
+      const eraser = createProduct({name: 'eraser', categoryId: 2});
+      // 'id' is the foreign key in Category in respect to Product when we talk about belongsTo
+      const result = buildLookupMap<unknown, Product, Category[]>(
+        [pen, eraser, pencil],
+        'categoryId',
+        reduceAsArray,
+      );
+      const expected = new Map<Number, Array<Product>>();
+      expected.set(1, [pen, pencil]);
+      expected.set(2, [eraser]);
+      expect(result).to.eql(expected);
+    });
+  });
+
+  describe('get the result of using reduceAsSingleItem strategy for belongsTo relation', () => {
+    it('returns one instance when one target instance is passed in', () => {
+      const cat = createCategory({name: 'stationery', id: 1});
+
+      const result = buildLookupMap<unknown, Category>(
+        [cat],
+        'id',
+        reduceAsSingleItem,
+      );
+      const expected = new Map<Number, Category>();
+      expected.set(1, cat);
+      expect(result).to.eql(expected);
+    });
+
+    it('returns multiple instances when multiple target instances are passed in', () => {
+      const cat1 = createCategory({name: 'stationery', id: 1});
+      const cat2 = createCategory({name: 'book', id: 2});
+
+      // 'id' is the foreign key in Category in respect to Product when we talk about belongsTo
+      const result = buildLookupMap<unknown, Category>(
+        [cat1, cat2],
+        'id',
+        reduceAsSingleItem,
+      );
+      const expected = new Map<Number, Category>();
+      expected.set(1, cat1);
+      expected.set(2, cat2);
+      expect(result).to.eql(expected);
+    });
+  });
+});

packages/repository/src/__tests__/unit/repositories/relations-helpers/find-by-foreign-keys.unit.ts

@@ -0,0 +1,147 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/repository
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+import {
+  expect,
+  createStubInstance,
+  sinon,
+  StubbedInstanceWithSinonAccessor,
+} from '@loopback/testlab';
+import {findByForeignKeys} from '../../../..';
+import {
+  ProductRepository,
+  Product,
+  createProduct,
+} from './relations-helpers-fixtures';
+
+describe('findByForeignKeys', () => {
+  let productRepo: StubbedInstanceWithSinonAccessor<ProductRepository>;
+
+  // use beforeEach to restore sinon stub
+  beforeEach(() => {
+    productRepo = createStubInstance(ProductRepository);
+  });
+
+  it('returns an empty array when no foreign keys are passed in', async () => {
+    const RESULTS: Product[] = [];
+    productRepo.stubs.find.resolves(RESULTS);
+
+    const fkIds: number[] = [];
+    await productRepo.create({id: 1, name: 'product', categoryId: 1});
+    const products = await findByForeignKeys(productRepo, 'categoryId', fkIds);
+    expect(products).to.be.empty();
+
+    sinon.assert.notCalled(productRepo.stubs.find);
+  });
+
+  it('returns an empty array when no instances have the foreign key value', async () => {
+    const find = productRepo.stubs.find;
+    find.resolves([]);
+    await productRepo.create({id: 1, name: 'product', categoryId: 1});
+    const products = await findByForeignKeys(productRepo, 'categoryId', 2);
+    expect(products).to.be.empty();
+    sinon.assert.calledWithMatch(find, {});
+  });
+
+  it('returns an empty array when no instances have the foreign key values', async () => {
+    const find = productRepo.stubs.find;
+    find.resolves([]);
+    await productRepo.create({id: 1, name: 'product', categoryId: 1});
+    const products = await findByForeignKeys(productRepo, 'categoryId', [2, 3]);
+    expect(products).to.be.empty();
+    sinon.assert.calledWithMatch(find, {});
+  });
+
+  it('returns all instances that have the foreign key value', async () => {
+    const find = productRepo.stubs.find;
+    const pen = createProduct({name: 'pen', categoryId: 1});
+    const pencil = createProduct({name: 'pencil', categoryId: 1});
+    find.resolves([pen, pencil]);
+
+    const products = await findByForeignKeys(productRepo, 'categoryId', 1);
+    expect(products).to.deepEqual([pen, pencil]);
+
+    sinon.assert.calledWithMatch(find, {
+      where: {
+        categoryId: 1,
+      },
+    });
+  });
+
+  it('does not include instances with different foreign key values', async () => {
+    const find = productRepo.stubs.find;
+    const pen = await productRepo.create({name: 'pen', categoryId: 1});
+    const pencil = await productRepo.create({name: 'pencil', categoryId: 2});
+    find.resolves([pen]);
+    const products = await findByForeignKeys(productRepo, 'categoryId', 1);
+    expect(products).to.deepEqual([pen]);
+    expect(products).to.not.containDeep(pencil);
+    sinon.assert.calledWithMatch(find, {
+      where: {
+        categoryId: 1,
+      },
+    });
+  });
+
+  it('includes instances when there is one value in the array of foreign key values', async () => {
+    const find = productRepo.stubs.find;
+    const pen = await productRepo.create({name: 'pen', categoryId: 1});
+    const pencil = await productRepo.create({name: 'pencil', categoryId: 2});
+    find.resolves([pencil]);
+    const products = await findByForeignKeys(productRepo, 'categoryId', [2]);
+    expect(products).to.deepEqual([pencil]);
+    expect(products).to.not.containDeep(pen);
+    sinon.assert.calledWithMatch(find, {
+      where: {
+        categoryId: 2,
+      },
+    });
+  });
+
+  it('returns all instances that have any of multiple foreign key values', async () => {
+    const pen = createProduct({name: 'pen', categoryId: 1});
+    const pencil = createProduct({name: 'pencil', categoryId: 2});
+    const paper = createProduct({name: 'paper', categoryId: 3});
+    const find = productRepo.stubs.find;
+    find.resolves([pen, paper]);
+    const products = await findByForeignKeys(productRepo, 'categoryId', [1, 3]);
+    expect(products).to.deepEqual([pen, paper]);
+    expect(products).to.not.containDeep(pencil);
+    sinon.assert.calledWithMatch(find, {
+      where: {
+        categoryId: {
+          inq: [1, 3],
+        },
+      },
+    });
+  });
+
+  // update the test when scope is supported
+  it('throws error if scope is passed in and is non-empty', async () => {
+    productRepo.stubs.find.resolves([]);
+    await expect(
+      findByForeignKeys(productRepo, 'categoryId', [1], {limit: 1}),
+    ).to.be.rejectedWith('scope is not supported');
+    sinon.assert.notCalled(productRepo.stubs.find);
+  });
+
+  // update the test when scope is supported
+  it('does not throw an error if scope is passed in and is undefined or empty', async () => {
+    const find = productRepo.stubs.find;
+    find.resolves([]);
+    let products = await findByForeignKeys(
+      productRepo,
+      'categoryId',
+      [1],
+      undefined,
+      {},
+    );
+    expect(products).to.be.empty();
+    sinon.assert.calledWithMatch(find, {});
+    products = await findByForeignKeys(productRepo, 'categoryId', 1, {}, {});
+    expect(products).to.be.empty();
+    sinon.assert.calledWithMatch(find, {});
+  });
+});