Minify each JS file individually, caching the result

This means that the expensive minification process will only be run for a file if it hasn't before. Greatly speeds up extension enabling/disabling.

Also:
- Don't check file last modification times in production for a bit of extra perf.
- Only flush CSS when theme settings are changed. This speeds up the page reload a bit.

src/Asset/AssetManager.php

@@ -106,9 +106,13 @@ class AssetManager
         return $this->js->getFile();
     }
 
-    public function flush()
+    public function flushCss()
     {
         $this->less->flush();
+    }
+
+    public function flushJs()
+    {
         $this->js->flush();
     }
 }

src/Asset/JsCompiler.php

@@ -11,54 +11,44 @@
 namespace Flarum\Asset;
 
 use Exception;
+use Illuminate\Cache\Repository;
 use MatthiasMullie\Minify;
 use s9e\TextFormatter\Configurator\JavaScript\Minifiers\ClosureCompilerService;
 
 class JsCompiler extends RevisionCompiler
 {
     /**
-     * @var bool
+     * @var Repository
      */
-    protected $minify;
+    protected $cache;
 
     /**
      * @param string $path
      * @param string $filename
-     * @param bool $minify
+     * @param bool $watch
+     * @param Repository $cache
      */
-    public function __construct($path, $filename, $minify = false)
+    public function __construct($path, $filename, $watch = false, Repository $cache = null)
     {
-        parent::__construct($path, $filename);
+        parent::__construct($path, $filename, $watch);
 
-        $this->minify = $minify;
+        $this->cache = $cache;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function format($string)
+    protected function format($string)
     {
-        return $string.";\n";
-    }
+        if (! $this->watch) {
+            $key = 'js.'.sha1($string);
 
-    /**
-     * @inheritDoc
-     */
-    public function compile()
-    {
-        $output = parent::compile();
-
-        if ($this->minify) {
-            set_time_limit(60);
-
-            try {
-                $output = $this->minifyWithClosureCompilerService($output);
-            } catch (Exception $e) {
-                $output = $this->minifyWithFallback($output);
-            }
+            $string = $this->cache->rememberForever($key, function () use ($string) {
+                return $this->minify($string);
+            });
         }
 
-        return $output;
+        return $string.";\n";
     }
 
     /**
@@ -66,7 +56,24 @@ class JsCompiler extends RevisionCompiler
      */
     protected function getCacheDifferentiator()
     {
-        return $this->minify;
+        return $this->watch;
+    }
+
+    /**
+     * @param string $source
+     * @return string
+     */
+    protected function minify($source)
+    {
+        set_time_limit(60);
+
+        try {
+            $source = $this->minifyWithClosureCompilerService($source);
+        } catch (Exception $e) {
+            $source = $this->minifyWithFallback($source);
+        }
+
+        return $source;
     }
 
     /**

src/Asset/LessCompiler.php

@@ -23,11 +23,12 @@ class LessCompiler extends RevisionCompiler
     /**
      * @param string $path
      * @param string $filename
+     * @param bool $watch
      * @param string $cachePath
      */
-    public function __construct($path, $filename, $cachePath)
+    public function __construct($path, $filename, $watch, $cachePath)
     {
-        parent::__construct($path, $filename);
+        parent::__construct($path, $filename, $watch);
 
         $this->cachePath = $cachePath;
     }

src/Asset/RevisionCompiler.php

@@ -24,14 +24,21 @@ class RevisionCompiler implements CompilerInterface
      */
     protected $strings = [];
 
+    /**
+     * @var bool
+     */
+    protected $watch;
+
     /**
      * @param string $path
      * @param string $filename
+     * @param bool $watch
      */
-    public function __construct($path, $filename)
+    public function __construct($path, $filename, $watch = false)
     {
         $this->path = $path;
         $this->filename = $filename;
+        $this->watch = $watch;
     }
 
     /**
@@ -63,18 +70,21 @@ class RevisionCompiler implements CompilerInterface
      */
     public function getFile()
     {
-        $old = $this->getRevision();
-
-        $lastModTime = 0;
-        foreach ($this->files as $file) {
-            $lastModTime = max($lastModTime, filemtime($file));
-        }
-
-        $current = hash('crc32b', serialize([$lastModTime, $this->getCacheDifferentiator()]));
+        $old = $current = $this->getRevision();
 
         $ext = pathinfo($this->filename, PATHINFO_EXTENSION);
         $file = $this->path.'/'.substr_replace($this->filename, '-'.$old, -strlen($ext) - 1, 0);
 
+        if ($this->watch) {
+            $cacheDifferentiator = [$this->getCacheDifferentiator()];
+
+            foreach ($this->files as $source) {
+                $cacheDifferentiator[] = [$source, filemtime($source)];
+            }
+
+            $current = hash('crc32b', serialize($cacheDifferentiator));
+        }
+
         $exists = file_exists($file);
 
         if (! $exists || $old !== $current) {
@@ -83,6 +93,7 @@ class RevisionCompiler implements CompilerInterface
             }
 
             $this->putRevision($current);
+
             $file = $this->path.'/'.substr_replace($this->filename, '-'.$current, -strlen($ext) - 1, 0);
             file_put_contents($file, $this->compile());
         }
@@ -115,7 +126,7 @@ class RevisionCompiler implements CompilerInterface
         $output = '';
 
         foreach ($this->files as $file) {
-            $output .= $this->format(file_get_contents($file));
+            $output .= $this->formatFile($file);
         }
 
         foreach ($this->strings as $callback) {
@@ -125,6 +136,15 @@ class RevisionCompiler implements CompilerInterface
         return $output;
     }
 
+    /**
+     * @param string $file
+     * @return string
+     */
+    protected function formatFile($file)
+    {
+        return $this->format(file_get_contents($file));
+    }
+
     /**
      * @return string
      */