test: mock console.error for proxy option tests and verify error logging

Author: bjohansebas

test/server/proxy-option.test.js

@@ -139,6 +139,7 @@ const proxyWithRouterAsObject = [
 describe("proxy option", () => {
   let proxyServer1;
   let proxyServer2;
+  let consoleMock;
 
   async function listenProxyServers() {
     const proxyApp1 = express();
@@ -837,12 +838,14 @@ describe("proxy option", () => {
     let customLogProvider;
 
     beforeAll(async () => {
+      consoleMock = jest.spyOn(console, "error");
+
       customLogProvider = {
         log: jest.fn(),
         debug: jest.fn(),
         info: jest.fn(),
         warn: jest.fn(),
-        error: jest.fn(),
+        error: () => console.error("custom error log"),
       };
 
       const compiler = webpack([config, config]);
@@ -869,6 +872,7 @@ describe("proxy option", () => {
     });
 
     afterAll(async () => {
+      consoleMock.mockRestore();
       await server.stop();
       await closeProxyServers();
     });
@@ -877,24 +881,18 @@ describe("proxy option", () => {
       it("respects a proxy option when a request path is matched", async () => {
         await req.get("/my-path");
 
-        expect(customLogProvider.error).toHaveBeenCalledTimes(1);
+        expect(consoleMock).toHaveBeenCalledTimes(1);
+        expect(consoleMock).toHaveBeenCalledWith("custom error log");
       });
     });
   });
 
   describe("should work and respect the `infrastructureLogging.level` option", () => {
     let server;
     let req;
-    let customLogProvider;
 
     beforeAll(async () => {
-      customLogProvider = {
-        log: jest.fn(),
-        debug: jest.fn(),
-        info: jest.fn(),
-        warn: jest.fn(),
-        error: jest.fn(),
-      };
+      consoleMock = jest.spyOn(console, "error");
 
       const compiler = webpack({
         ...config,
@@ -907,7 +905,6 @@ describe("proxy option", () => {
             {
               context: "/my-path",
               target: "http://unknown:1234",
-              logger: customLogProvider,
             },
           ],
           port: port3,
@@ -923,6 +920,7 @@ describe("proxy option", () => {
     });
 
     afterAll(async () => {
+      consoleMock.mockRestore();
       await server.stop();
       await closeProxyServers();
     });
@@ -931,24 +929,17 @@ describe("proxy option", () => {
       it("respects a proxy option when a request path is matched", async () => {
         await req.get("/my-path");
 
-        expect(customLogProvider.error).toHaveBeenCalledTimes(1);
+        expect(consoleMock).toHaveBeenCalledTimes(1);
       });
     });
   });
 
   describe("should work and respect the `infrastructureLogging.level` option with `none` value", () => {
     let server;
     let req;
-    let customLogProvider;
 
     beforeAll(async () => {
-      customLogProvider = {
-        log: jest.fn(),
-        debug: jest.fn(),
-        info: jest.fn(),
-        warn: jest.fn(),
-        error: jest.fn(),
-      };
+      consoleMock = jest.spyOn(console, "error");
 
       const compiler = webpack({
         ...config,
@@ -961,7 +952,6 @@ describe("proxy option", () => {
             {
               context: "/my-path",
               target: "http://unknown:1234",
-              logger: customLogProvider,
             },
           ],
           port: port3,
@@ -975,14 +965,16 @@ describe("proxy option", () => {
     });
 
     afterAll(async () => {
+      consoleMock.mockRestore();
       await server.stop();
     });
 
     describe("target", () => {
       it("respects a proxy option when a request path is matched", async () => {
         await req.get("/my-path");
 
-        expect(customLogProvider.error).toHaveBeenCalledTimes(0);
+        // Since infrastructureLogging.level is set to "none", no error logs should be produced but http-proxy-middleware still calls the error logger though no show.
+        expect(consoleMock).toHaveBeenCalledTimes(0);
       });
     });
   });