feat: allow using cjs as default config (#1775)

packages/webpack-cli/lib/groups/ConfigGroup.js

@@ -31,7 +31,8 @@ const modeAlias = {
 
 const getDefaultConfigFiles = () => {
     return DEFAULT_CONFIG_LOC.map((filename) => {
-        return Object.keys(extensions).map((ext) => {
+        // Since .cjs is not available on interpret side add it manually to default config extension list
+        return [...Object.keys(extensions), '.cjs'].map((ext) => {
             return {
                 path: resolve(filename + ext),
                 ext: ext,

test/zero-config/with-config/zero-config-entry.test.js → test/config/defaults/basic-config/default-js-config.test.js

@@ -1,10 +1,10 @@
 const fs = require('fs');
 const path = require('path');
-const { run } = require('../../utils/test-utils');
+const { run } = require('../../../utils/test-utils');
 
 describe('Zero Config', () => {
     it('runs when config is present but not supplied via flag', () => {
-        const { stdout, stderr } = run(__dirname, [], false);
+        const { stdout, stderr, exitCode } = run(__dirname, [], false);
         // default entry should be used
         expect(stdout).toContain('./index.js');
         // should pick up the output path from config
@@ -13,6 +13,8 @@ describe('Zero Config', () => {
         expect(stdout).toContain('Version');
         expect(stdout).toContain('Built at');
         expect(stdout).toContain('Time');
+        // Should return the correct exit code
+        expect(exitCode).toEqual(0);
         // check that the output file exists
         expect(fs.existsSync(path.join(__dirname, '/dist/test-output.js'))).toBeTruthy();
         expect(stderr).toBeFalsy();

test/config/defaults/cjs-config/default-cjs-config.test.js

@@ -0,0 +1,22 @@
+const fs = require('fs');
+const path = require('path');
+const { run } = require('../../../utils/test-utils');
+
+describe('Default Config:', () => {
+    it('Should be able to pick cjs config by default', () => {
+        const { stdout, stderr, exitCode } = run(__dirname, [], false);
+        // default entry should be used
+        expect(stdout).toContain('./index.js');
+        // should pick up the output path from config
+        expect(stdout).toContain('Entrypoint main = test-output');
+        expect(stdout).toContain('Hash');
+        expect(stdout).toContain('Version');
+        expect(stdout).toContain('Built at');
+        expect(stdout).toContain('Time');
+        // Should return the correct exit code
+        expect(exitCode).toEqual(0);
+        // check that the output file exists
+        expect(fs.existsSync(path.join(__dirname, '/dist/test-output.js'))).toBeTruthy();
+        expect(stderr).toBeFalsy();
+    });
+});

test/config/defaults/cjs-config/index.js

@@ -0,0 +1 @@
+console.log("Jotaro Kujo")

test/config/defaults/cjs-config/webpack.config.cjs

@@ -0,0 +1,6 @@
+module.exports = {
+    mode: 'development',
+    output: {
+        filename: 'test-output.js',
+    },
+};