feat: remove bypass option from proxy configuration

examples/general/proxy-advanced/webpack.config.js

@@ -8,19 +8,24 @@ module.exports = setup({
   context: __dirname,
   entry: "./app.js",
   devServer: {
-    proxy: {
-      "/api": {
+    port: 8080,
+    static: {
+      directory: ".",
+    },
+    proxy: [
+      {
+        context: "/api/nope",
+        router: () => "http://localhost:8080",
+        pathRewrite: () => "/bypass.html",
+      },
+      {
+        context: "/api",
         target: "http://jsonplaceholder.typicode.com/",
         changeOrigin: true,
         pathRewrite: {
           "^/api": "",
         },
-        bypass(req) {
-          if (req.url === "/api/nope") {
-            return "/bypass.html";
-          }
-        },
       },
-    },
+    ],
   },
 });

examples/proxy/webpack.config.js

@@ -29,10 +29,11 @@ module.exports = setup({
     onBeforeSetupMiddleware: async () => {
       await listenProxyServer();
     },
-    proxy: {
-      "/proxy": {
+    proxy: [
+      {
+        context: "/proxy",
         target: "http://localhost:5000",
       },
-    },
+    ],
   },
 });

lib/Server.js

@@ -3,7 +3,6 @@
 const os = require("node:os");
 const path = require("node:path");
 const url = require("node:url");
-const util = require("node:util");
 const fs = require("graceful-fs");
 const ipaddr = require("ipaddr.js");
 const { validate } = require("schema-utils");
@@ -138,14 +137,7 @@ const schema = require("./options.json");
  */
 
 /**
- * @callback ByPass
- * @param {Request} req
- * @param {Response} res
- * @param {ProxyConfigArrayItem} proxyConfig
- */
-
-/**
- * @typedef {{ path?: HttpProxyMiddlewareOptionsFilter | undefined, context?: HttpProxyMiddlewareOptionsFilter | undefined } & { bypass?: ByPass } & HttpProxyMiddlewareOptions } ProxyConfigArrayItem
+ * @typedef {{ path?: HttpProxyMiddlewareOptionsFilter | undefined, context?: HttpProxyMiddlewareOptionsFilter | undefined } & HttpProxyMiddlewareOptions } ProxyConfigArrayItem
  */
 
 /**
@@ -2148,29 +2140,13 @@ class Server {
        * @returns {RequestHandler | undefined} request handler
        */
       const getProxyMiddleware = (proxyConfig) => {
-        // It is possible to use the `bypass` method without a `target` or `router`.
-        // However, the proxy middleware has no use in this case, and will fail to instantiate.
-        if (proxyConfig.target) {
-          const context = proxyConfig.context || proxyConfig.path;
-
-          return createProxyMiddleware({
-            ...proxyConfig,
-            pathFilter: /** @type {string} */ (context),
-          });
-        }
+        const context =
+          proxyConfig.context || proxyConfig.path || proxyConfig.pathFilter;
 
-        if (proxyConfig.router) {
-          return createProxyMiddleware(proxyConfig);
-        }
-
-        // TODO improve me after drop `bypass` to always generate error when configuration is bad
-        if (!proxyConfig.bypass) {
-          util.deprecate(
-            () => {},
-            `Invalid proxy configuration:\n\n${JSON.stringify(proxyConfig, null, 2)}\n\nThe use of proxy object notation as proxy routes has been removed.\nPlease use the 'router' or 'context' options. Read more at https://github.com/chimurai/http-proxy-middleware/tree/v2.0.6#http-proxy-middleware-options`,
-            "DEP_WEBPACK_DEV_SERVER_PROXY_ROUTES_ARGUMENT",
-          )();
-        }
+        return createProxyMiddleware({
+          ...proxyConfig,
+          pathFilter: /** @type {string} */ (context),
+        });
       };
 
       /**
@@ -2236,40 +2212,7 @@ class Server {
             }
           }
 
-          // - Check if we have a bypass function defined
-          // - In case the bypass function is defined we'll retrieve the
-          // bypassUrl from it otherwise bypassUrl would be null
-          // TODO remove in the next major in favor `context` and `router` options
-          const isByPassFuncDefined = typeof proxyConfig.bypass === "function";
-          if (isByPassFuncDefined) {
-            util.deprecate(
-              () => {},
-              "Using the 'bypass' option is deprecated. Please use the 'router' or 'context' options. Read more at https://github.com/chimurai/http-proxy-middleware/tree/v2.0.6#http-proxy-middleware-options",
-              "DEP_WEBPACK_DEV_SERVER_PROXY_BYPASS_ARGUMENT",
-            )();
-          }
-          const bypassUrl = isByPassFuncDefined
-            ? await /** @type {ByPass} */ (proxyConfig.bypass)(
-                req,
-                res,
-                proxyConfig,
-              )
-            : null;
-
-          if (typeof bypassUrl === "boolean") {
-            // skip the proxy
-            res.statusCode = 404;
-            req.url = "";
-            next();
-          } else if (typeof bypassUrl === "string") {
-            // byPass to that url
-            req.url = bypassUrl;
-            next();
-          } else if (proxyMiddleware) {
-            return proxyMiddleware(req, res, next);
-          } else {
-            next();
-          }
+          return proxyMiddleware(req, res, next);
         };
 
         middlewares.push({

migration-v6.md

@@ -5,6 +5,7 @@ This document serves as a migration guide for `webpack-dev-server@6.0.0`.
 ## ⚠ Breaking Changes
 
 - Minimum supported `Node.js` version is `20.9.0`.
+- Minimum supported `webpack` version is `5.101.0`.
 - Support for **SockJS** in the WebSocket transport has been removed. Now, only **native WebSocket** is supported, or **custom** client and server implementations can be used.
 - The options for passing to the `proxy` have changed. Please refer to the [http-proxy-middleware migration guide](https://github.com/chimurai/http-proxy-middleware/blob/master/MIGRATION.md) for details.
 - Remove support for the spdy server type. Use the http2 server type instead; however, since Express does not work correctly with it, a custom server (e.g., Connect or Hono) should be used.
@@ -51,3 +52,46 @@ This document serves as a migration guide for `webpack-dev-server@6.0.0`.
   ```js
   const ip = Server.findIp("v4", true);
   ```
+
+- The bypass function in the proxy configuration was removed. Use the `pathFilter` and `router` for similar functionality. See the example below.
+
+  v4:
+
+  ```js
+  module.exports = {
+    // ...
+    devServer: {
+      proxy: [
+        {
+          context: "/api",
+          bypass(req, res, proxyOptions) {
+            if (req.url.startsWith("/api/special")) {
+              return "/special.html";
+            }
+          },
+        },
+      ],
+    },
+  };
+  ```
+
+  v5:
+
+  ```js
+  module.exports = {
+    // ...
+    devServer: {
+      proxy: [
+        {
+          pathFilter: "/api/special",
+          router: () => "http://localhost:3000", // Original Server
+          pathRewrite: () => "/special.html",
+        },
+      ],
+    },
+  };
+  ```
+
+  When `bypass` was used and that function returned a boolean, it would automatically result in a `404` request. This can’t be achieved in a similar way now, or, if it returned a string, you can do what was done in the example above.
+
+  `bypass` also allowed sending data; this can no longer be done. If you really need to do it, you’d have to create a new route in the proxy that sends the same data, or alternatively create a new route on the main server and, following the example above, send the data you wanted.