fix: allow passing promise function of webpack.config.js (#1947)

lib/utils/processOptions.js

@@ -6,12 +6,14 @@ const defaultPort = require('./defaultPort');
 function processOptions(config, argv, callback) {
   // processOptions {Promise}
   if (typeof config.then === 'function') {
-    config.then(processOptions).catch((err) => {
-      // eslint-disable-next-line no-console
-      console.error(err.stack || err);
-      // eslint-disable-next-line no-process-exit
-      process.exit();
-    });
+    config
+      .then((conf) => processOptions(conf, argv, callback))
+      .catch((err) => {
+        // eslint-disable-next-line no-console
+        console.error(err.stack || err);
+        // eslint-disable-next-line no-process-exit
+        process.exit(1);
+      });
 
     return;
   }

test/cli.test.js

@@ -100,6 +100,22 @@ describe('CLI', () => {
       .catch(done);
   });
 
+  it('should accept the promise function of webpack.config.js', (done) => {
+    testBin(
+      false,
+      resolve(__dirname, 'fixtures/promise-config/webpack.config.js')
+    )
+      .then((output) => {
+        expect(output.code).toEqual(0);
+        done();
+      })
+      .catch((err) => {
+        // for windows
+        expect(err.stdout.includes('Compiled successfully.')).toEqual(true);
+        done();
+      });
+  });
+
   it('should exit the process when SIGINT is detected', (done) => {
     const cliPath = resolve(__dirname, '../bin/webpack-dev-server.js');
     const examplePath = resolve(__dirname, '../examples/cli/public');

test/fixtures/promise-config/foo.js

@@ -0,0 +1,3 @@
+'use strict';
+
+console.log('i am foo!');

test/fixtures/promise-config/webpack.config.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const { join } = require('path');
+
+module.exports = () => {
+  return new Promise((resolve) => {
+    resolve({
+      mode: 'development',
+      entry: join(__dirname, 'foo.js'),
+    });
+  });
+};

test/helpers/test-bin.js

@@ -12,11 +12,9 @@ const basicConfigPath = path.resolve(
   '../fixtures/cli/webpack.config.js'
 );
 
-function runWebackDevServer(testArgs, configPath) {
+function testBin(testArgs, configPath) {
   const cwd = process.cwd();
   const env = process.env.NODE_ENV;
-  let stdout = '';
-  let stderr = '';
 
   if (!configPath) {
     configPath = basicConfigPath;
@@ -30,26 +28,7 @@ function runWebackDevServer(testArgs, configPath) {
 
   const args = [webpackDevServerPath, '--config', configPath].concat(testArgs);
 
-  return new Promise((resolve, reject) => {
-    const child = execa('node', args, { cwd, env });
-
-    child.on('error', (error) => reject(error));
-
-    child.stdout.on('data', (data) => {
-      stdout += data.toString();
-    });
-
-    child.stderr.on('data', (data) => {
-      stderr += data.toString();
-    });
-
-    child.on('close', (code) => {
-      if (code !== 0) {
-        return reject(stderr);
-      }
-      resolve({ stdout, stderr, code });
-    });
-  });
+  return execa('node', args, { cwd, env, timeout: 10000 });
 }
 
-module.exports = runWebackDevServer;
+module.exports = testBin;