test: support webapck5 (#2553)

Author: hiroppy

test/helpers/isWebpack5.js

@@ -0,0 +1,7 @@
+'use strict';
+
+const webpack = require('webpack');
+
+const isWebpack5 = webpack.version[0] === '5';
+
+module.exports = isWebpack5;

test/server/Server.test.js

@@ -7,6 +7,7 @@ const { noop } = require('webpack-dev-middleware/lib/util');
 const Server = require('../../lib/Server');
 const config = require('../fixtures/simple-config/webpack.config');
 const port = require('../ports-map').Server;
+const isWebpack5 = require('../helpers/isWebpack5');
 
 jest.mock('sockjs/lib/transport');
 
@@ -34,11 +35,20 @@ describe('Server', () => {
         })
       );
 
-      expect(
-        server.middleware.context.compiler.options.entry.map((p) => {
+      let entries;
+
+      if (isWebpack5) {
+        entries = server.middleware.context.compiler.options.entry.main.import.map(
+          (p) => {
+            return relative('.', p).split(sep);
+          }
+        );
+      } else {
+        entries = server.middleware.context.compiler.options.entry.map((p) => {
           return relative('.', p).split(sep);
-        })
-      ).toMatchSnapshot();
+        });
+      }
+      expect(entries).toMatchSnapshot();
       expect(server.middleware.context.compiler.options.plugins).toEqual([
         new webpack.HotModuleReplacementPlugin(),
       ]);
@@ -59,11 +69,21 @@ describe('Server', () => {
         })
       );
 
-      expect(
-        server.middleware.context.compiler.options.entry.map((p) => {
+      let entries;
+
+      if (isWebpack5) {
+        entries = server.middleware.context.compiler.options.entry.main.import.map(
+          (p) => {
+            return relative('.', p).split(sep);
+          }
+        );
+      } else {
+        entries = server.middleware.context.compiler.options.entry.map((p) => {
           return relative('.', p).split(sep);
-        })
-      ).toMatchSnapshot();
+        });
+      }
+
+      expect(entries).toMatchSnapshot();
       expect(server.middleware.context.compiler.options.plugins).toEqual([
         new webpack.HotModuleReplacementPlugin(),
       ]);

test/server/utils/updateCompiler.test.js

@@ -2,6 +2,7 @@
 
 const webpack = require('webpack');
 const updateCompiler = require('../../../lib/utils/updateCompiler');
+const isWebpack5 = require('../../helpers/isWebpack5');
 
 describe('updateCompiler', () => {
   describe('simple config, inline', () => {
@@ -36,7 +37,12 @@ describe('updateCompiler', () => {
       expect(compiler.hooks.entryOption.taps.length).toBe(1);
       expect(tapsByHMR).toEqual(0);
       expect(tapsByProvidePlugin).toEqual(1);
-      expect(compiler.options.plugins).toBeUndefined();
+
+      if (isWebpack5) {
+        expect(compiler.options.plugins).toEqual([]);
+      } else {
+        expect(compiler.options.plugins).toBeUndefined();
+      }
     });
   });