feat(boot): add a booter for interceptors

packages/boot/src/__tests__/fixtures/interceptor.artifact.ts

@@ -0,0 +1,54 @@
+// Copyright IBM Corp. 2019. 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 {
+  globalInterceptor,
+  Interceptor,
+  InvocationContext,
+  InvocationResult,
+  Provider,
+  ValueOrPromise,
+} from '@loopback/context';
+
+/**
+ * This class will be bound to the application as a global `Interceptor` during
+ * `boot`
+ */
+@globalInterceptor('auth', {tags: {name: 'myGlobalInterceptor'}})
+export class MyGlobalInterceptor implements Provider<Interceptor> {
+  /*
+  constructor() {}
+  */
+
+  /**
+   * This method is used by LoopBack context to produce an interceptor function
+   * for the binding.
+   *
+   * @returns An interceptor function
+   */
+  value() {
+    return this.intercept.bind(this);
+  }
+
+  /**
+   * The logic to intercept an invocation
+   * @param invocationCtx - Invocation context
+   * @param next - A function to invoke next interceptor or the target method
+   */
+  async intercept(
+    invocationCtx: InvocationContext,
+    next: () => ValueOrPromise<InvocationResult>,
+  ) {
+    try {
+      // Add pre-invocation logic here
+      const result = await next();
+      // Add post-invocation logic here
+      return result;
+    } catch (err) {
+      // Add error handling logic here
+      throw err;
+    }
+  }
+}

packages/boot/src/__tests__/fixtures/non-global-interceptor.artifact.ts

@@ -0,0 +1,54 @@
+// Copyright IBM Corp. 2019. 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 {
+  bind,
+  Interceptor,
+  InvocationContext,
+  InvocationResult,
+  Provider,
+  ValueOrPromise,
+} from '@loopback/context';
+
+/**
+ * This class will be bound to the application as a global `Interceptor` during
+ * `boot`
+ */
+@bind({tags: {namespace: 'interceptors', name: 'myInterceptor'}})
+export class MyInterceptor implements Provider<Interceptor> {
+  /*
+  constructor() {}
+  */
+
+  /**
+   * This method is used by LoopBack context to produce an interceptor function
+   * for the binding.
+   *
+   * @returns An interceptor function
+   */
+  value() {
+    return this.intercept.bind(this);
+  }
+
+  /**
+   * The logic to intercept an invocation
+   * @param invocationCtx - Invocation context
+   * @param next - A function to invoke next interceptor or the target method
+   */
+  async intercept(
+    invocationCtx: InvocationContext,
+    next: () => ValueOrPromise<InvocationResult>,
+  ) {
+    try {
+      // Add pre-invocation logic here
+      const result = await next();
+      // Add post-invocation logic here
+      return result;
+    } catch (err) {
+      // Add error handling logic here
+      throw err;
+    }
+  }
+}

packages/boot/src/__tests__/integration/interceptor.booter.integration.ts

@@ -0,0 +1,82 @@
+// Copyright IBM Corp. 2019. 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 {
+  BindingScope,
+  ContextTags,
+  GLOBAL_INTERCEPTOR_NAMESPACE,
+} from '@loopback/core';
+import {expect, TestSandbox} from '@loopback/testlab';
+import {resolve} from 'path';
+import {BooterApp} from '../fixtures/application';
+
+describe('interceptor script booter integration tests', () => {
+  const SANDBOX_PATH = resolve(__dirname, '../../.sandbox');
+  const sandbox = new TestSandbox(SANDBOX_PATH);
+
+  let app: BooterApp;
+
+  beforeEach('reset sandbox', () => sandbox.reset());
+  beforeEach(buildAppWithInterceptors);
+
+  it('boots global interceptors when app.boot() is called', async () => {
+    const expectedBinding = {
+      key: `${GLOBAL_INTERCEPTOR_NAMESPACE}.myGlobalInterceptor`,
+      tags: [
+        ContextTags.PROVIDER,
+        ContextTags.TYPE,
+        ContextTags.GLOBAL_INTERCEPTOR,
+        ContextTags.NAMESPACE,
+        ContextTags.GLOBAL_INTERCEPTOR_GROUP,
+        ContextTags.NAME,
+      ],
+      scope: BindingScope.TRANSIENT,
+    };
+
+    await app.boot();
+
+    const bindings = app
+      .findByTag(ContextTags.GLOBAL_INTERCEPTOR)
+      .map(b => ({key: b.key, tags: b.tagNames, scope: b.scope}));
+    expect(bindings).to.containEql(expectedBinding);
+  });
+
+  it('boots non-global interceptors when app.boot() is called', async () => {
+    const expectedBinding = {
+      key: `interceptors.myInterceptor`,
+      tags: [
+        ContextTags.PROVIDER,
+        ContextTags.TYPE,
+        ContextTags.NAMESPACE,
+        ContextTags.NAME,
+      ],
+      scope: BindingScope.TRANSIENT,
+    };
+
+    await app.boot();
+
+    const binding = app.getBinding('interceptors.myInterceptor');
+    expect({
+      key: binding.key,
+      tags: binding.tagNames,
+      scope: binding.scope,
+    }).to.eql(expectedBinding);
+  });
+
+  async function buildAppWithInterceptors() {
+    await sandbox.copyFile(resolve(__dirname, '../fixtures/application.js'));
+    await sandbox.copyFile(
+      resolve(__dirname, '../fixtures/interceptor.artifact.js'),
+      'interceptors/interceptor.interceptor.js',
+    );
+    await sandbox.copyFile(
+      resolve(__dirname, '../fixtures/non-global-interceptor.artifact.js'),
+      'interceptors/non-global-interceptor.interceptor.js',
+    );
+
+    const MyApp = require(resolve(SANDBOX_PATH, 'application.js')).BooterApp;
+    app = new MyApp();
+  }
+});

packages/boot/src/boot.component.ts

@@ -9,9 +9,10 @@ import {
   ApplicationMetadataBooter,
   ControllerBooter,
   DataSourceBooter,
+  InterceptorProviderBooter,
+  LifeCycleObserverBooter,
   RepositoryBooter,
   ServiceBooter,
-  LifeCycleObserverBooter,
 } from './booters';
 import {Bootstrapper} from './bootstrapper';
 import {BootBindings} from './keys';
@@ -31,6 +32,7 @@ export class BootComponent implements Component {
     ServiceBooter,
     DataSourceBooter,
     LifeCycleObserverBooter,
+    InterceptorProviderBooter,
   ];
 
   /**

packages/boot/src/booters/index.ts

@@ -3,11 +3,12 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
+export * from './application-metadata.booter';
 export * from './base-artifact.booter';
 export * from './booter-utils';
 export * from './controller.booter';
 export * from './datasource.booter';
+export * from './interceptor.booter';
+export * from './lifecyle-observer.booter';
 export * from './repository.booter';
 export * from './service.booter';
-export * from './application-metadata.booter';
-export * from './lifecyle-observer.booter';

packages/boot/src/booters/interceptor.booter.ts

@@ -0,0 +1,76 @@
+// 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 {
+  BindingScope,
+  Constructor,
+  createBindingFromClass,
+  inject,
+  Interceptor,
+  Provider,
+} from '@loopback/context';
+import {Application, CoreBindings} from '@loopback/core';
+import * as debugFactory from 'debug';
+import {ArtifactOptions} from '../interfaces';
+import {BootBindings} from '../keys';
+import {BaseArtifactBooter} from './base-artifact.booter';
+
+const debug = debugFactory('loopback:boot:interceptor-booter');
+
+type InterceptorProviderClass = Constructor<Provider<Interceptor>>;
+
+/**
+ * A class that extends BaseArtifactBooter to boot the 'InterceptorProvider' artifact type.
+ *
+ * Supported phases: configure, discover, load
+ *
+ * @param app Application instance
+ * @param projectRoot Root of User Project relative to which all paths are resolved
+ * @param [bootConfig] InterceptorProvider Artifact Options Object
+ */
+export class InterceptorProviderBooter extends BaseArtifactBooter {
+  interceptors: InterceptorProviderClass[];
+
+  constructor(
+    @inject(CoreBindings.APPLICATION_INSTANCE)
+    public app: Application,
+    @inject(BootBindings.PROJECT_ROOT) projectRoot: string,
+    @inject(`${BootBindings.BOOT_OPTIONS}#interceptors`)
+    public interceptorConfig: ArtifactOptions = {},
+  ) {
+    super(
+      projectRoot,
+      // Set InterceptorProvider Booter Options if passed in via bootConfig
+      Object.assign({}, InterceptorProviderDefaults, interceptorConfig),
+    );
+  }
+
+  /**
+   * Uses super method to get a list of Artifact classes. Boot each file by
+   * creating a DataSourceConstructor and binding it to the application class.
+   */
+  async load() {
+    await super.load();
+
+    this.interceptors = this.classes as InterceptorProviderClass[];
+    for (const interceptor of this.interceptors) {
+      debug('Bind interceptor: %s', interceptor.name);
+      const binding = createBindingFromClass(interceptor, {
+        defaultScope: BindingScope.TRANSIENT,
+      });
+      this.app.add(binding);
+      debug('Binding created for interceptor: %j', binding);
+    }
+  }
+}
+
+/**
+ * Default ArtifactOptions for DataSourceBooter.
+ */
+export const InterceptorProviderDefaults: ArtifactOptions = {
+  dirs: ['interceptors'],
+  extensions: ['.interceptor.js'],
+  nested: true,
+};