From a3e8ee830215f528111dfc8d6b66205ec95295bf Mon Sep 17 00:00:00 2001
From: Nitin Kumar <snitin315@gmail.com>
Date: Thu, 17 Sep 2020 14:13:13 +0530
Subject: [PATCH] fix: show warning if bail and watch are used together

---
 packages/webpack-cli/lib/groups/ConfigGroup.js |  6 ++++++
 packages/webpack-cli/lib/utils/Compiler.js     |  5 +++++
 test/bail/bail-and-watch-warning.test.js       | 12 ++++++++++++
 test/bail/main.js                              |  1 +
 test/bail/webpack.config.js                    |  6 ++++++
 test/core-flags/bail-flag.test.js              |  8 ++++++++
 6 files changed, 38 insertions(+)
 create mode 100644 test/bail/bail-and-watch-warning.test.js
 create mode 100644 test/bail/main.js
 create mode 100644 test/bail/webpack.config.js

diff --git a/packages/webpack-cli/lib/groups/ConfigGroup.js b/packages/webpack-cli/lib/groups/ConfigGroup.js
index ed22885fce9..64cedceb59e 100644
--- a/packages/webpack-cli/lib/groups/ConfigGroup.js
+++ b/packages/webpack-cli/lib/groups/ConfigGroup.js
@@ -127,6 +127,12 @@ class ConfigGroup extends GroupHelper {
             newOptionsObject['options'] = configOptions;
         }
 
+        //warn the user if bail and watch both are used together
+        const { bail, watch } = newOptionsObject['options'];
+        if (bail && watch) {
+            logger.warn('You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.');
+        }
+
         if (configOptions && configPath.includes('.webpack')) {
             const currentPath = configPath;
             const parentContext = dirname(currentPath).split(sep).slice(0, -1).join(sep);
diff --git a/packages/webpack-cli/lib/utils/Compiler.js b/packages/webpack-cli/lib/utils/Compiler.js
index 20774ddbe9e..4a2c4686e96 100644
--- a/packages/webpack-cli/lib/utils/Compiler.js
+++ b/packages/webpack-cli/lib/utils/Compiler.js
@@ -117,6 +117,11 @@ class Compiler {
             return interactive(options, outputOptions);
         }
 
+        //warn the user if bail and watch both are used together
+        if (this.compiler.options.bail && outputOptions.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) => {
                 this.setUpHookForCompilation(comp, outputOptions, options[idx]);
diff --git a/test/bail/bail-and-watch-warning.test.js b/test/bail/bail-and-watch-warning.test.js
new file mode 100644
index 00000000000..9700436421d
--- /dev/null
+++ b/test/bail/bail-and-watch-warning.test.js
@@ -0,0 +1,12 @@
+'use strict';
+
+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']);
+
+        expect(stderr).toContain(`You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.`);
+        expect(stdout).toBeTruthy();
+    });
+});
diff --git a/test/bail/main.js b/test/bail/main.js
new file mode 100644
index 00000000000..15e0a061dc2
--- /dev/null
+++ b/test/bail/main.js
@@ -0,0 +1 @@
+console.log('bail and watch warning test');
diff --git a/test/bail/webpack.config.js b/test/bail/webpack.config.js
new file mode 100644
index 00000000000..e066755baef
--- /dev/null
+++ b/test/bail/webpack.config.js
@@ -0,0 +1,6 @@
+module.exports = {
+    entry: './main.js',
+    mode: 'development',
+    bail: true,
+    watch: true,
+};
diff --git a/test/core-flags/bail-flag.test.js b/test/core-flags/bail-flag.test.js
index 48587933155..d938bdf2609 100644
--- a/test/core-flags/bail-flag.test.js
+++ b/test/core-flags/bail-flag.test.js
@@ -16,4 +16,12 @@ describe('--bail flag', () => {
         expect(stderr).toBeFalsy();
         expect(stdout).toContain('bail: false');
     });
+
+    it('should log warning if --bail and --watch are used together', () => {
+        const { stderr, stdout } = run(__dirname, ['--bail', '--watch']);
+
+        expect(stderr).toContain(`You are using "bail" with "watch". "bail" will still exit webpack when the first error is found.`);
+        expect(stdout).toContain('bail: true');
+        expect(stdout).toContain('watch: true');
+    });
 });