Allow disabling default build if multiple entry points are defined

Author: emodric

README.md

@@ -22,6 +22,8 @@ file:
 webpack_encore:
     # The path where Encore is building the assets - i.e. Encore.setOutputPath()
     output_path: '%kernel.project_dir%/public/build'
+    # If multiple builds are defined (as shown below), you can disable the default build:
+    # output_path: false
 
     # if you have multiple builds:
     # builds:

src/DependencyInjection/Configuration.php

@@ -23,6 +23,12 @@ public function getConfigTreeBuilder()
         $rootNode = method_exists($treeBuilder, 'getRootNode') ? $treeBuilder->getRootNode() : $treeBuilder->root('webpack_encore');
 
         $rootNode
+            ->validate()
+                ->ifTrue(function (array $v): bool {
+                    return false === $v['output_path'] && empty($v['builds']);
+                })
+                ->thenInvalid('Default build can only be disabled if multiple entry points are defined.')
+            ->end()
             ->children()
                 ->scalarNode('output_path')
                     ->isRequired()

src/DependencyInjection/WebpackEncoreExtension.php

@@ -30,12 +30,14 @@ public function load(array $configs, ContainerBuilder $container)
         $configuration = $this->getConfiguration($configs, $container);
         $config = $this->processConfiguration($configuration, $configs);
 
-        $factories = [
-            '_default' => $this->entrypointFactory($container, '_default', $config['output_path'], $config['cache']),
-        ];
-        $cacheKeys = [
-            '_default' => $config['output_path'].'/'.self::ENTRYPOINTS_FILE_NAME,
-        ];
+        $factories = [];
+        $cacheKeys = [];
+
+        if (false !== $config['output_path']) {
+            $factories['_default'] = $this->entrypointFactory($container, '_default', $config['output_path'], $config['cache']);
+            $cacheKeys['_default'] = $config['output_path'].'/'.self::ENTRYPOINTS_FILE_NAME;
+        }
+
         foreach ($config['builds'] as $name => $path) {
             $factories[$name] = $this->entrypointFactory($container, $name, $path, $config['cache']);
             $cacheKeys[rawurlencode($name)] = $path.'/'.self::ENTRYPOINTS_FILE_NAME;