test(server): add create-loopback util

Author: Walker Leite

template/test/server/boot.spec.js

@@ -1,21 +1,17 @@
 /* eslint-disable arrow-body-style */
-import loopback from 'loopback';
-import boot from 'loopback-boot';
-import path from 'path';
+import createLoopback from './utils/create-loopback';
 import request from 'supertest';
 {{#extended}}
 import initialAccount from '../../server/initial-data/maintenance-account.json';
 {{/extended}}
 
 describe('boot process', () => {
   let server;
-  const options = {
-    appRootDir: path.resolve(__dirname, '../../server'),
-    scriptExtensions: ['.js', '.json', '.node', '.ejs'],
-  };
-  beforeEach((done) => {
-    server = loopback();
-    boot(server, options, done);
+
+  beforeEach(() => {
+    return createLoopback().then((s) => {
+      server = s;
+    });
   });
 
   afterEach((done) => {

template/test/server/utils/create-loopback.js

@@ -0,0 +1,19 @@
+import path from 'path';
+import loopback from 'loopback';
+import boot from 'loopback-boot';
+
+export default function(options) {
+  const defaultOptions = {
+    appRootDir: path.resolve(__dirname, '../../../server'),
+    scriptExtensions: ['.js', '.json', '.node', '.ejs'],
+  };
+
+  return new Promise((resolve) => {
+    const server = loopback();
+    boot(
+      server,
+      Object.assign(defaultOptions, options),
+      () => resolve(server)
+    );
+  });
+}

template/test/server/utils/create-loopback.spec.js

@@ -0,0 +1,48 @@
+import createLoopback from './create-loopback';
+import loopback from 'loopback';
+import boot from 'loopback-boot';
+
+jest.mock('loopback');
+jest.mock('loopback-boot');
+
+describe('createLoopback dev util', () => {
+  it('exports a promise', () => {
+    expect(createLoopback()).toBeInstanceOf(Promise);
+  });
+
+  it('calls loopback-boot with default options', () => {
+    const mockServer = {};
+    const optsMatcher = {
+      appRootDir: expect.any(String),
+      scriptExtensions: expect.any(Array),
+    };
+    loopback.mockReturnValue(mockServer);
+    createLoopback()
+    expect(boot).toBeCalledWith(
+      mockServer,
+      expect.objectContaining(optsMatcher),
+      expect.any(Function),
+    );
+  });
+
+  it('calls loopback-boot with custom options', () => {
+    const mockServer = {};
+    const myOpts = {myOpt: true};
+    loopback.mockReturnValue(mockServer);
+    createLoopback(myOpts)
+    expect(boot).toBeCalledWith(
+      mockServer,
+      expect.objectContaining(myOpts),
+      expect.any(Function),
+    );
+  });
+
+  it('resolves with loopback server', async () => {
+    const mockServer = {};
+    loopback.mockReturnValue(mockServer);
+    // just call callback fn
+    boot.mockImplementation((s, o, r) => r());
+    const server = await createLoopback();
+    expect(server).toEqual(mockServer);
+  });
+})