refactor(example-todo): use datasource cli generated files and dataso…

…urce booters

Signed-off-by: Taranveer Virk <[email protected]>

examples/todo/src/application.ts

@@ -6,7 +6,6 @@
 import {ApplicationConfig} from '@loopback/core';
 import {RestApplication} from '@loopback/rest';
 import {MySequence} from './sequence';
-import {db} from './datasources/db.datasource';
 
 /* tslint:disable:no-unused-variable */
 // Binding and Booter imports are required to infer types for BootMixin!
@@ -40,17 +39,5 @@ export class TodoListApplication extends BootMixin(
         nested: true,
       },
     };
-
-    this.setupDatasources();
-  }
-
-  setupDatasources() {
-    // This will allow you to test your application without needing to
-    // use a "real" datasource!
-    const datasource =
-      this.options && this.options.datasource
-        ? new juggler.DataSource(this.options.datasource)
-        : db;
-    this.dataSource(datasource);
   }
 }

examples/todo/config/datasources.json → examples/todo/src/datasources/db.datasource.json

@@ -1,5 +1,6 @@
 {
   "name": "db",
   "connector": "memory",
+  "localStorage": "",
   "file": "./data/db.json"
 }

examples/todo/src/datasources/db.datasource.ts

@@ -3,22 +3,11 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
-import * as path from 'path';
-// The juggler reference must exist for consuming code to correctly infer
-// type info used in the "db" export (contained in juggler.DataSource).
-// tslint:disable-next-line:no-unused-variable
-import {juggler} from '@loopback/repository';
+import {inject} from '@loopback/core';
+import {juggler, DataSource} from '@loopback/repository';
 
-const dsConfigPath = path.resolve(
-  __dirname,
-  '../../../config/datasources.json',
-);
-const config = require(dsConfigPath);
-
-// TODO(bajtos) Ideally, datasources should be created by @loopback/boot
-// and registered with the app for dependency injection.
-// However, we need to investigate how to access these datasources from
-// integration tests where we don't have access to the full app object.
-// For example, @loopback/boot can provide a helper function for
-// performing a partial boot that creates datasources only.
-export const db = new juggler.DataSource(config);
+export class DbDataSource extends juggler.DataSource {
+  constructor(@inject('datasources.config.db') dsConfig: DataSource) {
+    super(dsConfig);
+  }
+}

examples/todo/src/datasources/index.ts

@@ -0,0 +1,6 @@
+// Copyright IBM Corp. 2017,2018. All Rights Reserved.
+// Node module: @loopback/example-todo
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+export * from './db.datasource';

examples/todo/test/acceptance/application.acceptance.ts

@@ -9,6 +9,7 @@ import {TodoListApplication} from '../../src/application';
 import {TodoRepository} from '../../src/repositories/';
 import {givenTodo} from '../helpers';
 import {Todo} from '../../src/models/';
+import {BindingScope} from '@loopback/context';
 
 describe('Application', () => {
   let app: TodoListApplication;
@@ -19,6 +20,21 @@ describe('Application', () => {
   before(givenAnApplication);
   before(async () => {
     await app.boot();
+
+    /**
+     * Override DataSource to not write to file for testing. Since we aren't
+     * persisting data to file and each injection normally instatiates a new
+     * instance, we must change the BindingScope to a singleton so only one
+     * instance is created and used for all injections (preserving access to
+     * the same memory space).
+     */
+    app.bind('datasources.config.db').to({
+      name: 'db',
+      connector: 'memory',
+    });
+    app.find('datasources.db')[0].inScope(BindingScope.SINGLETON);
+
+    // Start Application
     await app.start();
   });
   before(givenARestServer);
@@ -109,10 +125,6 @@ describe('Application', () => {
       rest: {
         port: 0,
       },
-      datasource: {
-        name: 'db',
-        connector: 'memory',
-      },
     });
   }