test: add empty entry case (#3030)

Author: snitin315

test/e2e/DevServer.test.js

@@ -32,6 +32,19 @@ describe('DevServer', () => {
     }
   );
 
+  webpack5Test(
+    'should add devServer entry points to an empty entry object',
+    (done) => {
+      testBin('--config ./test/fixtures/dev-server/empty-entry.js')
+        .then((output) => {
+          expect(output.exitCode).toEqual(0);
+          expect(output.stdout).toContain('client/default/index.js?');
+          done();
+        })
+        .catch(done);
+    }
+  );
+
   webpack5Test('should supports entry as descriptor', (done) => {
     testBin(
       '--config ./test/fixtures/entry-as-descriptor/webpack.config --stats detailed'

test/fixtures/dev-server/empty-entry.js

@@ -0,0 +1,13 @@
+'use strict';
+
+module.exports = {
+  mode: 'development',
+  stats: 'detailed',
+  entry: {},
+  devServer: {
+    transportMode: {
+      server: 'sockjs',
+      client: 'sockjs',
+    },
+  },
+};