Add a webpack encore helper to Twig

src/Sculpin/Bundle/TwigBundle/DependencyInjection/Configuration.php

@@ -43,6 +43,13 @@ public function getConfigTreeBuilder(): TreeBuilder
                     ->defaultValue(['', 'twig', 'html', 'html.twig', 'twig.html'])
                     ->prototype('scalar')->end()
                 ->end()
+                ->scalarNode('webpack_manifest')
+                    ->info(
+                        'Optional relative path to the Webpack Encore manifest file within source/ '
+                        . '(e.g., "build/manifest.json")'
+                    )
+                    ->defaultNull()
+                ->end()
             ->end();
 
         return $treeBuilder;

src/Sculpin/Bundle/TwigBundle/DependencyInjection/SculpinTwigExtension.php

@@ -37,6 +37,7 @@ public function load(array $configs, ContainerBuilder $container): void
         $container->setParameter('sculpin_twig.source_view_paths', $config['source_view_paths']);
         $container->setParameter('sculpin_twig.view_paths', $config['view_paths']);
         $container->setParameter('sculpin_twig.extensions', $config['extensions']);
+        $container->setParameter('sculpin_twig.webpack_manifest', $config['webpack_manifest']);
 
         if (! extension_loaded('intl')) {
             // Do not enable the intl Twig extension if the intl PHP extension is not installed.

src/Sculpin/Bundle/TwigBundle/Resources/config/services.xml

@@ -52,6 +52,12 @@
             <tag name="twig.extension" />
         </service>
 
+        <service id="sculpin_twig.helpers.webpack_encore_helper" class="Sculpin\Bundle\TwigBundle\WebpackEncoreHelper">
+            <argument>%sculpin.source_dir%</argument>
+            <argument>%sculpin_twig.webpack_manifest%</argument>
+            <tag name="twig.extension" />
+        </service>
+
     </services>
 
 </container>

src/Sculpin/Bundle/TwigBundle/WebpackEncoreHelper.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sculpin\Bundle\TwigBundle;
+
+use Twig\Extension\AbstractExtension;
+use Twig\Extension\GlobalsInterface;
+
+class WebpackEncoreHelper extends AbstractExtension implements GlobalsInterface
+{
+    protected $sourceDir;
+    protected $manifest;
+
+    public function __construct(string $sourceDir, ?string $manifest)
+    {
+        $this->sourceDir = $sourceDir;
+        $this->manifest = $manifest;
+    }
+
+    public function getGlobals(): array
+    {
+        $manifestContents = $this->getManifestContents();
+
+        if (!$manifestContents) {
+            return [
+                'webpack_manifest' =>
+                    [
+                        'error' => 'Please configure the `sculpin_twig.webpack_manifest` variable '
+                            . 'in your app/config/sculpin_kernel.yml file. For example:' . "\n\n"
+                            . 'sculpin_twig:' . "\n"
+                            . '    webpack_manifest: build/manifest.json'
+                    ]
+            ];
+        }
+
+        $manifest = json_decode($manifestContents, true);
+
+        return [
+            'webpack_manifest' => $manifest,
+        ];
+    }
+
+    private function getManifestContents(): string
+    {
+        $path = $this->sourceDir . DIRECTORY_SEPARATOR . $this->manifest;
+
+        if (!file_exists($path) || !is_readable($path)) {
+            return '';
+        }
+
+        return file_get_contents($path);
+    }
+}

src/Sculpin/Tests/Functional/Fixture/webpack_manifest/manifest.json

@@ -0,0 +1,4 @@
+{
+    "build/css/app.css": "/build/css/app.9141cd43.css",
+    "build/js/app.js": "/build/js/app.43dcc737.js"
+}

src/Sculpin/Tests/Functional/Fixture/webpack_manifest/manifest_test.md

@@ -0,0 +1,7 @@
+---
+title: testing webpack manifest
+---
+
+Testing CSS {{ webpack_manifest['build/css/app.css']|default('/build/css/app.css') }}
+Testing JS {{ webpack_manifest['build/js/app.js']|default('/build/js/app.js') }}
+

src/Sculpin/Tests/Functional/FunctionalTestCase.php

@@ -42,8 +42,8 @@ protected function setUpTestProject(): void
         $this->tearDownTestProject();
 
         $projectFiles = [
-            '/config/sculpin_kernel.yml',
-            '/config/sculpin_site.yml',
+            '/app/config/sculpin_kernel.yml',
+            '/app/config/sculpin_site.yml',
             '/source/_layouts/default.html.twig',
             '/source/_layouts/raw.html.twig',
         ];

src/Sculpin/Tests/Functional/GenerateCommandTest.php

@@ -6,6 +6,17 @@
 
 class GenerateCommandTest extends FunctionalTestCase
 {
+    public const CONFIG_FILE = DIRECTORY_SEPARATOR . 'app'
+        . DIRECTORY_SEPARATOR . 'config'
+        . DIRECTORY_SEPARATOR . 'sculpin_kernel.yml';
+
+    public function tearDown()
+    {
+        parent::tearDown();
+
+        $this->writeToProjectFile(self::CONFIG_FILE, '');
+    }
+
     /** @test */
     public function shouldGenerateInSpecifiedOutputDir(): void
     {
@@ -43,4 +54,30 @@ public function shouldGenerateUsingSpecifiedSourceDir(): void
         // check that it worked
         $this->assertProjectHasFile($filePath, "Expected project to have generated file at path $filePath.");
     }
+
+    /** @test */
+    public function shouldExposeWebpackManifestInTwig(): void
+    {
+        $this->configureForWebpack();
+        $this->copyFixtureToProject(__DIR__ . '/Fixture/webpack_manifest/manifest_test.md', '/source/test.md');
+        $this->copyFixtureToProject(__DIR__ . '/Fixture/webpack_manifest/manifest.json', '/source/build/manifest.json');
+
+        $this->executeSculpin('generate');
+
+        $filePath = '/test/index.html';
+        $msg      = "Expected project to have generated file at path $filePath.";
+
+        $this->assertProjectHasFile('/output_test' . $filePath, $msg);
+        $this->assertGeneratedFileHasContent($filePath, 'Testing CSS /build/css/app.9141cd43.css');
+        $this->assertGeneratedFileHasContent($filePath, 'Testing JS /build/js/app.43dcc737.js');
+    }
+
+    protected function configureForWebpack(): void
+    {
+        $this->writeToProjectFile(
+            self::CONFIG_FILE,
+            'sculpin_twig:' . "\n"
+            . '    webpack_manifest: build/manifest.json' . "\n"
+        );
+    }
 }