fix: legacy API (#3660)

Author: alexander-akait

Diff for: lib/Server.js

@@ -25,7 +25,7 @@ class Server {
         "DEP_WEBPACK_DEV_SERVER_CONSTRUCTOR"
       )();
 
-      [options, compiler] = [compiler, options];
+      [options = {}, compiler] = [compiler, options];
     }
 
     validate(schema, options, "webpack Dev Server");

Diff for: test/e2e/__snapshots__/api.test.js.snap.webpack4

@@ -22,7 +22,7 @@ Array [
 
 exports[`API should work with callback API: page errors 1`] = `Array []`;
 
-exports[`API should work with deprecated API: console messages 1`] = `
+exports[`API should work with deprecated API ('listen' and \`close\` methods): console messages 1`] = `
 Array [
   "[HMR] Waiting for update signal from WDS...",
   "Hey.",
@@ -31,4 +31,26 @@ Array [
 ]
 `;
 
-exports[`API should work with deprecated API: page errors 1`] = `Array []`;
+exports[`API should work with deprecated API ('listen' and \`close\` methods): page errors 1`] = `Array []`;
+
+exports[`API should work with deprecated API (only compiler in constructor): console messages 1`] = `
+Array [
+  "[HMR] Waiting for update signal from WDS...",
+  "Hey.",
+  "[webpack-dev-server] Hot Module Replacement enabled.",
+  "[webpack-dev-server] Live Reloading enabled.",
+]
+`;
+
+exports[`API should work with deprecated API (only compiler in constructor): page errors 1`] = `Array []`;
+
+exports[`API should work with deprecated API (the order of the arguments in the constructor): console messages 1`] = `
+Array [
+  "[HMR] Waiting for update signal from WDS...",
+  "Hey.",
+  "[webpack-dev-server] Hot Module Replacement enabled.",
+  "[webpack-dev-server] Live Reloading enabled.",
+]
+`;
+
+exports[`API should work with deprecated API (the order of the arguments in the constructor): page errors 1`] = `Array []`;

Diff for: test/e2e/__snapshots__/api.test.js.snap.webpack5

@@ -22,7 +22,7 @@ Array [
 
 exports[`API should work with callback API: page errors 1`] = `Array []`;
 
-exports[`API should work with deprecated API: console messages 1`] = `
+exports[`API should work with deprecated API ('listen' and \`close\` methods): console messages 1`] = `
 Array [
   "[HMR] Waiting for update signal from WDS...",
   "Hey.",
@@ -31,4 +31,26 @@ Array [
 ]
 `;
 
-exports[`API should work with deprecated API: page errors 1`] = `Array []`;
+exports[`API should work with deprecated API ('listen' and \`close\` methods): page errors 1`] = `Array []`;
+
+exports[`API should work with deprecated API (only compiler in constructor): console messages 1`] = `
+Array [
+  "[HMR] Waiting for update signal from WDS...",
+  "Hey.",
+  "[webpack-dev-server] Hot Module Replacement enabled.",
+  "[webpack-dev-server] Live Reloading enabled.",
+]
+`;
+
+exports[`API should work with deprecated API (only compiler in constructor): page errors 1`] = `Array []`;
+
+exports[`API should work with deprecated API (the order of the arguments in the constructor): console messages 1`] = `
+Array [
+  "[HMR] Waiting for update signal from WDS...",
+  "Hey.",
+  "[webpack-dev-server] Hot Module Replacement enabled.",
+  "[webpack-dev-server] Live Reloading enabled.",
+]
+`;
+
+exports[`API should work with deprecated API (the order of the arguments in the constructor): page errors 1`] = `Array []`;

Diff for: test/e2e/api.test.js

@@ -79,7 +79,7 @@ describe("API", () => {
     });
   });
 
-  it(`should work with deprecated API`, async () => {
+  it("should work with deprecated API ('listen' and `close` methods)", async () => {
     const compiler = webpack(config);
     const devServerOptions = { port };
     const server = new Server(devServerOptions, compiler);
@@ -125,4 +125,71 @@ describe("API", () => {
       });
     });
   });
+
+  it(`should work with deprecated API (the order of the arguments in the constructor)`, async () => {
+    const compiler = webpack(config);
+    const devServerOptions = { port };
+    const server = new Server(compiler, devServerOptions);
+
+    await server.start();
+
+    const { page, browser } = await runBrowser();
+
+    const pageErrors = [];
+    const consoleMessages = [];
+
+    page
+      .on("console", (message) => {
+        consoleMessages.push(message);
+      })
+      .on("pageerror", (error) => {
+        pageErrors.push(error);
+      });
+
+    await page.goto(`http://127.0.0.1:${port}/main`, {
+      waitUntil: "networkidle0",
+    });
+
+    expect(consoleMessages.map((message) => message.text())).toMatchSnapshot(
+      "console messages"
+    );
+    expect(pageErrors).toMatchSnapshot("page errors");
+
+    await browser.close();
+    await server.stop();
+  });
+
+  it(`should work with deprecated API (only compiler in constructor)`, async () => {
+    const compiler = webpack(config);
+    const server = new Server(compiler);
+
+    server.options.port = port;
+
+    await server.start();
+
+    const { page, browser } = await runBrowser();
+
+    const pageErrors = [];
+    const consoleMessages = [];
+
+    page
+      .on("console", (message) => {
+        consoleMessages.push(message);
+      })
+      .on("pageerror", (error) => {
+        pageErrors.push(error);
+      });
+
+    await page.goto(`http://127.0.0.1:${port}/main`, {
+      waitUntil: "networkidle0",
+    });
+
+    expect(consoleMessages.map((message) => message.text())).toMatchSnapshot(
+      "console messages"
+    );
+    expect(pageErrors).toMatchSnapshot("page errors");
+
+    await browser.close();
+    await server.stop();
+  });
 });