feat(event-handler): implemented route prefixes in HTTP event handler (#4523)

Co-authored-by: Andrea Amorosi <dreamorosi@gmail.com>

Author: sdangol

packages/event-handler/src/rest/Router.ts

@@ -56,6 +56,10 @@ class Router {
    * Whether the router is running in development mode.
    */
   protected readonly isDev: boolean = false;
+  /**
+   * The base prefix to be used for all routes registered using this Router.
+   */
+  protected readonly prefix?: Path;
 
   public constructor(options?: RestRouterOptions) {
     this.context = {};
@@ -73,6 +77,7 @@ class Router {
       logger: this.logger,
     });
     this.isDev = isDevMode();
+    this.prefix = options?.prefix;
   }
 
   /**
@@ -238,9 +243,9 @@ class Router {
           );
         } else {
           const handler =
-            options?.scope != null
-              ? route.handler.bind(options.scope)
-              : route.handler;
+            options?.scope == null
+              ? route.handler
+              : route.handler.bind(options.scope);
 
           const handlerResult = await handler(params, reqCtx);
           reqCtx.res = handlerResultToWebResponse(
@@ -281,9 +286,15 @@ class Router {
   public route(handler: RouteHandler, options: RestRouteOptions): void {
     const { method, path, middleware = [] } = options;
     const methods = Array.isArray(method) ? method : [method];
+    let resolvedPath = path;
+    if (this.prefix) {
+      resolvedPath = path === '/' ? this.prefix : `${this.prefix}${path}`;
+    }
 
     for (const method of methods) {
-      this.routeRegistry.register(new Route(method, path, handler, middleware));
+      this.routeRegistry.register(
+        new Route(method, resolvedPath, handler, middleware)
+      );
     }
   }
 

packages/event-handler/src/types/rest.ts

@@ -43,6 +43,10 @@ type RestRouterOptions = {
    * When no logger is provided, we'll only log warnings and errors using the global `console` object.
    */
   logger?: GenericLogger;
+  /**
+   * The base prefix to be used for all routes registered using this Router.
+   */
+  prefix?: Path;
 };
 
 interface CompiledRoute {

packages/event-handler/tests/unit/rest/Router/basic-routing.test.ts

@@ -117,4 +117,31 @@ describe('Class: Router - Basic Routing', () => {
       InternalServerError
     );
   });
+
+  it('routes to the prefixed path when having a shared prefix defined', async () => {
+    // Prepare
+    const app = new Router({
+      prefix: '/todos',
+    });
+    app.post('/', async () => {
+      return { actualPath: '/todos' };
+    });
+    app.get('/:todoId', async ({ todoId }) => {
+      return { actualPath: `/todos/${todoId}` };
+    });
+
+    // Act
+    const createResult = await app.resolve(
+      createTestEvent('/todos', 'POST'),
+      context
+    );
+    const getResult = await app.resolve(
+      createTestEvent('/todos/1', 'GET'),
+      context
+    );
+
+    // Assess
+    expect(JSON.parse(createResult.body).actualPath).toBe('/todos');
+    expect(JSON.parse(getResult.body).actualPath).toBe('/todos/1');
+  });
 });