fix(binding-http): middleware as a function

packages/binding-http/README.md

@@ -310,17 +310,17 @@ The exposed thing on the internal server will product form URLs such as:
 
 ### Adding a middleware
 
-HttpServer supports the addition of **middleware** to handle the raw HTTP requests before they hit the Servient. In the middleware you can run some logic to filter and eventually reject HTTP requests (e.g. based on some custom headers).
+HttpServer supports the addition of **middleware** to handle the raw HTTP requests before they hit the Servient. In the middleware function, you can run some logic to filter and eventually reject HTTP requests (e.g. based on some custom headers).
 
-This can be done by passing an instance of HttpMiddleware to the HttpServer constructor.
+This can be done by passing a middleware function to the HttpServer constructor.
 
 ```js
 const { Servient } = require("@node-wot/core");
-const { HttpMiddleware, HttpServer } = require("@node-wot/binding-http");
+const { HttpServer } = require("@node-wot/binding-http");
 
 const servient = new Servient();
 
-const middleware = new HttpMiddleware(async (req, res, next) => {
+const middleware = async (req, res, next) => {
     // For example, reject requests in which the X-Custom-Header header is missing
     // by replying with 400 Bad Request
     if (!req.headers["x-custom-header"]) {
@@ -330,7 +330,7 @@ const middleware = new HttpMiddleware(async (req, res, next) => {
     }
     // Pass all other requests to the WoT Servient
     next();
-});
+};
 
 const httpServer = new HttpServer({
     port,

packages/binding-http/src/http-server-middleware.ts

@@ -17,35 +17,19 @@
  * HTTP Middleware for the HTTP Server
  */
 
-import { createLoggers } from "@node-wot/core";
 import * as http from "http";
 
-const { debug } = createLoggers("binding-http", "http-server-middleware");
-
-/**
- * A function that handles a request and passes it to the WoT Servient.
- * See {@link HttpMiddleware} for an example.
- * @param req The HTTP request.
- * @param res The HTTP response.
- * @param next Call this function to pass the request to the WoT Servient.
- */
-export type MiddlewareRequestHandler = (
-    req: http.IncomingMessage,
-    res: http.ServerResponse,
-    next: () => void
-) => Promise<void>;
-
 /**
- * A middleware for the HTTP server, which can be used to intercept requests before they are handled by the WoT Servient.
+ * A middleware function for the HTTP server, which can be used to intercept requests before they are handled by the WoT Servient.
  *
  * Example:
  * ```javascript
  * import { Servient } from "@node-wot/core";
- * import { HttpMiddleware, HttpServer } from "@node-wot/binding-http";
+ * import { HttpServer, MiddlewareRequestHandler } from "@node-wot/binding-http";
  *
  * const servient = new Servient();
  *
- * const middleware = new HttpMiddleware(async (req, res, next) => {
+ * const middleware: MiddlewareRequestHandler = async (req, res, next) => {
  *     // For example, reject requests in which the X-Custom-Header header is missing
 *      // by replying with 400 Bad Request
  *     if (!req.headers["x-custom-header"]) {
@@ -55,7 +39,7 @@ export type MiddlewareRequestHandler = (
  *     }
  *     // Pass all other requests to the WoT Servient
  *     next();
- * });
+ * };
 
  * const httpServer = new HttpServer({
  *     port,
@@ -68,16 +52,12 @@ export type MiddlewareRequestHandler = (
  *    // ...
  * });
  * ```
+ * @param req The HTTP request.
+ * @param res The HTTP response.
+ * @param next Call this function to pass the request to the WoT Servient.
  */
-export default class HttpMiddleware {
-    public handler: MiddlewareRequestHandler;
-
-    constructor(handler: MiddlewareRequestHandler) {
-        this.handler = handler;
-    }
-
-    public handleRequest(req: http.IncomingMessage, res: http.ServerResponse, next: () => void): Promise<void> {
-        debug("Hit middleware");
-        return this.handler(req, res, next);
-    }
-}
+export type MiddlewareRequestHandler = (
+    req: http.IncomingMessage,
+    res: http.ServerResponse,
+    next: () => void
+) => Promise<void>;

packages/binding-http/src/http-server.ts

@@ -43,7 +43,7 @@ import slugify from "slugify";
 import { ThingDescription } from "wot-typescript-definitions";
 import * as acceptLanguageParser from "accept-language-parser";
 import { ActionElement, EventElement, PropertyElement } from "wot-thing-description-types";
-import HttpMiddleware from "./http-server-middleware";
+import { MiddlewareRequestHandler } from "./http-server-middleware";
 
 const { debug, info, warn, error } = createLoggers("binding-http", "http-server");
 
@@ -66,7 +66,7 @@ export default class HttpServer implements ProtocolServer {
     private readonly httpSecurityScheme: string = "NoSec"; // HTTP header compatible string
     private readonly validOAuthClients: RegExp = /.*/g;
     private readonly server: http.Server | https.Server = null;
-    private readonly middleware: HttpMiddleware = null;
+    private readonly middleware: MiddlewareRequestHandler = null;
     private readonly things: Map<string, ExposedThing> = new Map<string, ExposedThing>();
     private servient: Servient = null;
     private oAuthValidator: Validator;
@@ -112,7 +112,7 @@ export default class HttpServer implements ProtocolServer {
             this.scheme = "https";
             this.server = https.createServer(options, (req, res) => {
                 if (this.middleware) {
-                    this.middleware.handleRequest(req, res, () => {
+                    this.middleware(req, res, () => {
                         this.handleRequest(req, res);
                     });
                 } else {
@@ -123,7 +123,7 @@ export default class HttpServer implements ProtocolServer {
             this.scheme = "http";
             this.server = http.createServer((req, res) => {
                 if (this.middleware) {
-                    this.middleware.handleRequest(req, res, () => {
+                    this.middleware(req, res, () => {
                         this.handleRequest(req, res);
                     });
                 } else {

packages/binding-http/src/http.ts

@@ -15,18 +15,17 @@
 
 import * as TD from "@node-wot/td-tools";
 import { Method } from "./oauth-token-validation";
-import HttpMiddleware from "./http-server-middleware";
+import { MiddlewareRequestHandler } from "./http-server-middleware";
 
 export { default as HttpServer } from "./http-server";
 export { default as HttpClient } from "./http-client";
 export { default as HttpClientFactory } from "./http-client-factory";
 export { default as HttpsClientFactory } from "./https-client-factory";
-export { default as HttpMiddleware } from "./http-server-middleware";
+export { MiddlewareRequestHandler } from "./http-server-middleware";
 export * from "./http-server";
 export * from "./http-client";
 export * from "./http-client-factory";
 export * from "./https-client-factory";
-export * from "./http-server-middleware";
 
 export interface HttpProxyConfig {
     href: string;
@@ -46,7 +45,7 @@ export interface HttpConfig {
     serverKey?: string;
     serverCert?: string;
     security?: TD.SecurityScheme;
-    middleware?: HttpMiddleware;
+    middleware?: MiddlewareRequestHandler;
 }
 
 export interface OAuth2ServerConfig extends TD.SecurityScheme {

packages/binding-http/test/http-server-test.ts

@@ -27,7 +27,7 @@ import { Content, createLoggers, ExposedThing, Helpers } from "@node-wot/core";
 import { DataSchemaValue, InteractionInput, InteractionOptions } from "wot-typescript-definitions";
 import chaiAsPromised from "chai-as-promised";
 import { Readable } from "stream";
-import HttpMiddleware from "../src/http-server-middleware";
+import { MiddlewareRequestHandler } from "../src/http-server-middleware";
 
 const { debug, error } = createLoggers("binding-http", "http-server-test");
 
@@ -51,14 +51,14 @@ class HttpServerTest {
     }
 
     @test async "should use middleware if provided"() {
-        const middleware = new HttpMiddleware(async (req, res, next) => {
+        const middleware: MiddlewareRequestHandler = async (req, res, next) => {
             if (req.url.endsWith("testMiddleware")) {
                 res.statusCode = 401;
                 res.end("Unauthorized");
             } else {
                 next();
             }
-        });
+        };
 
         const httpServer = new HttpServer({
             port,