test: add unit test for BootMixin

packages/boot/test/unit/boot.mixin.unit.ts

@@ -0,0 +1,85 @@
+// Copyright IBM Corp. 2018. All Rights Reserved.
+// Node module: @loopback/boot
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+import {expect} from '@loopback/testlab';
+import {BootMixin, Booter, BootBindings} from '../../';
+import {Application} from '@loopback/core';
+
+describe('BootMxiin unit tests', () => {
+  let app: AppWithBootMixin;
+
+  beforeEach(getApp);
+
+  it('mixes into the target class', () => {
+    expect(app.boot).to.be.a.Function();
+    expect(app.booters).to.be.a.Function();
+  });
+
+  it('adds BootComponent to target class', () => {
+    const boundComponent = app.find('components.*').map(b => b.key);
+    expect(boundComponent).to.containEql('components.BootComponent');
+  });
+
+  it('binds booter from app.booters()', async () => {
+    app.booters(TestBooter);
+    const booter = await app.get(`${BootBindings.BOOTER_PREFIX}.TestBooter`);
+    expect(booter).to.be.an.instanceOf(TestBooter);
+  });
+
+  it('binds multiple booter classes from app.booters()', async () => {
+    app.booters(TestBooter, AnotherTestBooter);
+    const booter = await app.get(`${BootBindings.BOOTER_PREFIX}.TestBooter`);
+    expect(booter).to.be.an.instanceOf(TestBooter);
+
+    const anotherBooter = await app.get(
+      `${BootBindings.BOOTER_PREFIX}.AnotherTestBooter`,
+    );
+    expect(anotherBooter).to.be.an.instanceOf(AnotherTestBooter);
+  });
+
+  it('binds user defined component without a booter', async () => {
+    class EmptyTestComponent {}
+
+    app.component(EmptyTestComponent);
+    const compInstance = await app.get('components.EmptyTestComponent');
+    expect(compInstance).to.be.an.instanceOf(EmptyTestComponent);
+  });
+
+  it('binds a user defined component with a booter from .component()', async () => {
+    class TestComponent {
+      booters = [TestBooter];
+    }
+
+    app.component(TestComponent);
+    const compInstance = await app.get('components.TestComponent');
+    expect(compInstance).to.be.an.instanceOf(TestComponent);
+    const booterInst = await app.get(
+      `${BootBindings.BOOTER_PREFIX}.TestBooter`,
+    );
+    expect(booterInst).to.be.an.instanceOf(TestBooter);
+  });
+
+  class TestBooter implements Booter {
+    configured = false;
+
+    async configure() {
+      this.configured = true;
+    }
+  }
+
+  class AnotherTestBooter implements Booter {
+    discovered = false;
+
+    async discover() {
+      this.discovered = true;
+    }
+  }
+
+  class AppWithBootMixin extends BootMixin(Application) {}
+
+  function getApp() {
+    app = new AppWithBootMixin();
+  }
+});