refactor: config group to pure function and move away from group design (#1811)

* chore: remove default value from config/entry flag
* refactor: ConfigGroup remove from group design

Author: anshumanv

packages/serve/__tests__/__snapshots__/parseArgs.test.ts.snap

@@ -11,7 +11,6 @@ Object {
   },
   "webpackArgs": Object {
     "color": true,
-    "config": Array [],
     "hot": true,
     "mode": "production",
   },
@@ -41,7 +40,6 @@ Object {
   },
   "webpackArgs": Object {
     "color": true,
-    "config": Array [],
     "mode": "development",
   },
 }

packages/webpack-cli/__tests__/ConfigGroup/ConfigGroup.test.js

@@ -7,7 +7,7 @@ const promiseConfig = require('./webpack.promise.config.cjs');
 
 describe('ConfigGroup', function () {
     it('should handle merge properly', async () => {
-        const group = new ConfigGroup([
+        const result = await ConfigGroup([
             {
                 merge: true,
             },
@@ -16,7 +16,6 @@ describe('ConfigGroup', function () {
             },
         ]);
 
-        const result = await group.run();
         const expectedOptions = {
             output: { filename: './dist-commonjs.js', libraryTarget: 'commonjs' },
             entry: './a.js',
@@ -30,35 +29,31 @@ describe('ConfigGroup', function () {
     });
 
     it('should return array for multiple config', async () => {
-        const group = new ConfigGroup([
+        const result = await ConfigGroup([
             { config: [resolve(__dirname, './webpack.config1.cjs'), resolve(__dirname, './webpack.config2.cjs')] },
         ]);
-        const result = await group.run();
         const expectedOptions = [config1, config2];
         expect(result.options).toEqual(expectedOptions);
         expect(result.outputOptions).toEqual({});
     });
 
     it('should return config object for single config', async () => {
-        const group = new ConfigGroup([{ config: [resolve(__dirname, './webpack.config1.cjs')] }]);
-        const result = await group.run();
+        const result = await ConfigGroup([{ config: [resolve(__dirname, './webpack.config1.cjs')] }]);
         expect(result.options).toEqual(config1);
         expect(result.outputOptions).toEqual({});
     });
 
     it('should return resolved config object for promise config', async () => {
-        const group = new ConfigGroup([{ config: [resolve(__dirname, './webpack.promise.config.cjs')] }]);
-        const result = await group.run();
+        const result = await ConfigGroup([{ config: [resolve(__dirname, './webpack.promise.config.cjs')] }]);
         const expectedOptions = await promiseConfig();
         expect(result.options).toEqual(expectedOptions);
         expect(result.outputOptions).toEqual({});
     });
 
     it('should handle configs returning different types', async () => {
-        const group = new ConfigGroup([
+        const result = await ConfigGroup([
             { config: [resolve(__dirname, './webpack.promise.config.cjs'), resolve(__dirname, './webpack.config.cjs')] },
         ]);
-        const result = await group.run();
         const resolvedPromiseConfig = await promiseConfig();
         const expectedOptions = [resolvedPromiseConfig, ...arrayConfig];
         expect(result.options).toEqual(expectedOptions);