feat: warn when user modifies output.path directly

Author: yyx990803

packages/@vue/cli-service/lib/PluginAPI.js

@@ -1,4 +1,5 @@
 const path = require('path')
+const chalk = require('chalk')
 const { matchesPluginId } = require('@vue/cli-shared-utils')
 
 class PluginAPI {
@@ -114,7 +115,18 @@ class PluginAPI {
    * @return {object} Raw webpack config.
    */
   resolveWebpackConfig (chainableConfig) {
-    return this.service.resolveWebpackConfig(chainableConfig)
+    const config = this.service.resolveWebpackConfig(chainableConfig)
+    // performa a few warning checks
+    const options = this.service.projectOptions
+    if (config.output.path !== this.resolve(options.outputDir)) {
+      console.error(chalk.red(
+        `\n\nConfiguration Error: ` +
+        `Avoid modifying webpack output.path directly. ` +
+        `Use the "outputDir" option instead.\n`
+      ))
+      process.exit(1)
+    }
+    return config
   }
 
   /**