refactor: deprecate bypass option in proxy (#4827)

Author: snitin315

lib/Server.js

@@ -3,6 +3,7 @@
 const os = require("os");
 const path = require("path");
 const url = require("url");
+const util = require("util");
 const fs = require("graceful-fs");
 const ipaddr = require("ipaddr.js");
 const { validate } = require("schema-utils");
@@ -2084,6 +2085,13 @@ class Server {
           // 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' and '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,

test/server/proxy-option.test.js

@@ -1,6 +1,7 @@
 "use strict";
 
 const path = require("path");
+const util = require("util");
 const request = require("supertest");
 const express = require("express");
 const bodyParser = require("body-parser");
@@ -214,6 +215,18 @@ describe("proxy option", () => {
     });
 
     describe("bypass", () => {
+      it("should log deprecation warning when bypass is used", async () => {
+        const utilSpy = jest.spyOn(util, "deprecate");
+
+        expect(utilSpy.mock.calls[0][1]).toEqual(
+          "Using the 'bypass' option is deprecated. Please use the 'router' and 'context' options. Read more at https://github.com/chimurai/http-proxy-middleware/tree/v2.0.6#http-proxy-middleware-options"
+        );
+        expect(utilSpy.mock.calls[0][2]).toEqual(
+          "DEP_WEBPACK_DEV_SERVER_PROXY_BYPASS_ARGUMENT"
+        );
+
+        utilSpy.mockRestore();
+      });
       it("can rewrite a request path", async () => {
         const response = await req.get("/foo/bar.html");