fix: handle multi compilers

packages/webpack-cli/lib/utils/Compiler.js

@@ -1,5 +1,6 @@
 const webpack = require('webpack');
 const logger = require('./logger');
+const bailAndWatchWarning = require('./warnings/bailAndWatchWarning');
 const { CompilerOutput } = require('./CompilerOutput');
 
 class Compiler {
@@ -117,16 +118,13 @@ class Compiler {
             return interactive(options, outputOptions);
         }
 
-        //warn the user if bail and watch both are used together
-        if (!this.compiler.compilers && this.compiler.options.bail && this.compiler.watch) {
-            logger.warn('You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.');
-        }
-
         if (this.compiler.compilers) {
             this.compiler.compilers.forEach((comp, idx) => {
+                bailAndWatchWarning(comp); //warn the user if bail and watch both are used together
                 this.setUpHookForCompilation(comp, outputOptions, options[idx]);
             });
         } else {
+            bailAndWatchWarning(this.compiler);
             this.setUpHookForCompilation(this.compiler, outputOptions, options);
         }
 

packages/webpack-cli/lib/utils/warnings/bailAndWatchWarning.js

@@ -0,0 +1,7 @@
+const logger = require('../logger');
+
+module.exports = (compiler) => {
+    if (compiler.options.bail && compiler.watch) {
+        logger.warn('You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.');
+    }
+};

test/bail/bail-and-watch-warning.test.js

@@ -3,8 +3,15 @@
 const { run } = require('../utils/test-utils');
 
 describe('bail and watch warning', () => {
-    it('should log warning if bail and watch both options are true', () => {
-        const { stderr, stdout } = run(__dirname, ['-c', 'webpack.config.js']);
+    it('should log warning in case of single compiler', () => {
+        const { stderr, stdout } = run(__dirname, ['-c', 'single-webpack.config.js']);
+
+        expect(stderr).toContain(`You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.`);
+        expect(stdout).toBeTruthy();
+    });
+
+    it('should log warning in case of multiple compilers', () => {
+        const { stderr, stdout } = run(__dirname, ['-c', 'multi-webpack.config.js']);
 
         expect(stderr).toContain(`You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.`);
         expect(stdout).toBeTruthy();

test/bail/multi-webpack.config.js

@@ -0,0 +1,20 @@
+module.exports = [
+    {
+        output: {
+            filename: './dist-first.js',
+        },
+        name: 'first',
+        entry: './src/first.js',
+        mode: 'development',
+    },
+    {
+        output: {
+            filename: './dist-second.js',
+        },
+        name: 'second',
+        entry: './src/second.js',
+        mode: 'production',
+        bail: true,
+        watch: true,
+    },
+];

test/bail/webpack.config.js → test/bail/single-webpack.config.js

@@ -1,5 +1,5 @@
 module.exports = {
-    entry: './main.js',
+    entry: './src/first.js',
     mode: 'development',
     bail: true,
     watch: true,

test/bail/src/first.js

@@ -0,0 +1 @@
+console.log('bail and watch warning test first');

test/bail/src/second.js

@@ -0,0 +1 @@
+console.log('bail and watch warning test second');