feat(rest): add openapi enhancer service

add openapi spec enhancer to rest server impl. loopbackio#4380 Signed-off-by: Douglas McConnachie <[email protected]>
dougal83 · Feb 24, 2020 · f572622 · f572622
1 parent 2123d9b
commit f572622
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diff --git a/packages/rest/src/__tests__/unit/rest.server/fixtures/info.spec.extension.ts b/packages/rest/src/__tests__/unit/rest.server/fixtures/info.spec.extension.ts
@@ -0,0 +1,33 @@
+// Copyright IBM Corp. 2019. All Rights Reserved.
+// Node module: @loopback/openapi-v3
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+import {bind} from '@loopback/core';
+import debugModule from 'debug';
+import {inspect} from 'util';
+import {
+  asSpecEnhancer,
+  mergeOpenAPISpec,
+  OASEnhancer,
+  OpenApiSpec,
+} from '../../../..';
+
+const debug = debugModule('loopback:openapi:spec-enhancer');
+
+/**
+ * A spec enhancer to add OpenAPI info spec
+ */
+@bind(asSpecEnhancer)
+export class InfoSpecEnhancer implements OASEnhancer {
+  name = 'info';
+
+  modifySpec(spec: OpenApiSpec): OpenApiSpec {
+    const InfoPatchSpec = {
+      info: {title: 'LoopBack Test Application', version: '1.0.1'},
+    };
+    const mergedSpec = mergeOpenAPISpec(spec, InfoPatchSpec);
+    debug(`security spec extension, merged spec: ${inspect(mergedSpec)}`);
+    return mergedSpec;
+  }
+}
diff --git a/packages/rest/src/__tests__/unit/rest.server/rest.server.open-api-spec.unit.ts b/packages/rest/src/__tests__/unit/rest.server/rest.server.open-api-spec.unit.ts
@@ -3,7 +3,7 @@
 // This file is licensed under the MIT License.
 // License text available at https://opensource.org/licenses/MIT
 
-import {Application} from '@loopback/core';
+import {Application, createBindingFromClass} from '@loopback/core';
 import {anOpenApiSpec, anOperationSpec} from '@loopback/openapi-spec-builder';
 import {get, post, requestBody} from '@loopback/openapi-v3';
 import {model, property} from '@loopback/repository';
@@ -13,6 +13,7 @@ import {
   RestComponent,
   RestServer,
 } from '../../..';
+import {InfoSpecEnhancer} from './fixtures/info.spec.extension';
 
 describe('RestServer.getApiSpec()', () => {
   let app: Application;
@@ -311,6 +312,16 @@ describe('RestServer.getApiSpec()', () => {
     });
   });
 
+  it('invokes registered oas enhancers', async () => {
+    const EXPECTED_SPEC_INFO = {
+      title: 'LoopBack Test Application',
+      version: '1.0.1',
+    };
+    server.add(createBindingFromClass(InfoSpecEnhancer));
+    const spec = await server.getApiSpec();
+    expect(spec.info).to.eql(EXPECTED_SPEC_INFO);
+  });
+
   async function givenApplication() {
     app = new Application();
     app.component(RestComponent);

diff --git a/packages/rest/src/rest.server.ts b/packages/rest/src/rest.server.ts
@@ -9,12 +9,15 @@ import {
   BindingScope,
   Constructor,
   Context,
+  createBindingFromClass,
   inject,
 } from '@loopback/context';
 import {Application, CoreBindings, Server} from '@loopback/core';
 import {HttpServer, HttpServerOptions} from '@loopback/http-server';
 import {
   getControllerSpec,
+  OASEnhancerService,
+  OAS_ENHANCER_SERVICE,
   OpenAPIObject,
   OpenApiSpec,
   OperationObject,
@@ -130,6 +133,12 @@ export class RestServer extends Context implements Server, HttpServerLike {
    * @param res - The response.
    */
 
+  protected _OASEnhancer: OASEnhancerService;
+  public get OASEnhancer(): OASEnhancerService {
+    this._setupOASEnhancerIfNeeded();
+    return this._OASEnhancer;
+  }
+
   protected _requestHandler: HttpRequestListener;
   public get requestHandler(): HttpRequestListener {
     if (this._requestHandler == null) {
@@ -219,6 +228,16 @@ export class RestServer extends Context implements Server, HttpServerLike {
     this.bind(RestBindings.HANDLER).toDynamicValue(() => this.httpHandler);
   }
 
+  protected _setupOASEnhancerIfNeeded() {
+    if (this._OASEnhancer != null) return;
+    this.add(
+      createBindingFromClass(OASEnhancerService, {
+        key: OAS_ENHANCER_SERVICE,
+      }),
+    );
+    this._OASEnhancer = this.getSync(OAS_ENHANCER_SERVICE);
+  }
+
   protected _setupRequestHandlerIfNeeded() {
     if (this._expressApp != null) return;
     this._expressApp = express();
@@ -754,6 +773,10 @@ export class RestServer extends Context implements Server, HttpServerLike {
       spec = this.updateSpecFromRequest(spec, requestContext);
     }
 
+    // Apply OAS enhancers to the OpenAPI specification
+    this.OASEnhancer.spec = spec;
+    spec = await this.OASEnhancer.applyAllEnhancers();
+
     return spec;
   }