Start writing unit tests

src/Twig/Functions/IconExtension.php

@@ -4,22 +4,98 @@ declare(strict_types=1);
 
 namespace Pcm\IconBundle\Twig\Functions;
 
+use Exception;
+use InvalidArgumentException;
 use Twig\Extension\AbstractExtension;
 use Twig\TwigFunction;
+use TypeError;
 
 final class IconExtension extends AbstractExtension
 {
+    public function __construct(private array $directories) {}
+
+    private const DEFAULT_OPTIONS = [
+        'icon' => null,
+        'title' => null,
+    ];
+
     /**
      * @inheritDoc
      */
     public function getFunctions(): array
     {
         return [
-            new TwigFunction('icon', [$this, 'render'], [
+            new TwigFunction('icon', [$this, 'renderIcon'], [
                 'is_safe' => ['html']
             ])
         ];
     }
+
+    /**
+     * @param array $options
+     */
+    public function renderIcon(array $userOptions): string
+    {
+        $options = $this->mergeUserOptionsWithDefaults($userOptions);
+
+        $iconFilepath = $this->findSvgFilepath($options['icon']);
+        $rawSvgMarkup = $this->getSvgMarkup($iconFilepath);
+        $cleanSvgMarkup = $this->cleanSvgMarkup($rawSvgMarkup);
+
+        if ($this->titleIsANonEmptyString($options['title'])) {
+            $markup = $this->addTitleToMarkup($cleanSvgMarkup, $options['title']);
+        }
+
+        return $markup;
+    }
+
+    private function mergeUserOptionsWithDefaults(array $userOptions): array
+    {
+        return array_merge(self::DEFAULT_OPTIONS, $userOptions);
+    }
+
+    private function findSvgFilepath(string $iconName): string
+    {
+        foreach ($this->directories as $directory) {
+            $potentialFilepath = sprintf('%s/%s.svg', $directory, $iconName);
+            if (file_exists($potentialFilepath)) {
+                return $potentialFilepath;
+            }
+        }
+
+        throw new IconNotFound(sprintf('File "%s.svg" not found in %s', $iconName, implode(', ', $this->directories)));
+    }
+
+    private function getSvgMarkup(string $filepath): string
+    {
+        return file_get_contents($filepath);
+    }
+
+    private function cleanSvgMarkup(string $markup): string
+    {
+        return preg_replace('/<title>.*<\/title>/', '', $markup);
+    }
+
+    private function titleIsANonEmptyString(mixed $title): bool
+    {
+        if (!is_string($title) && null !== $title)
+            throw new TypeError('Title must be a string!');
+
+
+        if ('' === $title)
+            throw new InvalidArgumentException('Title string must not be empty!');
+
+        return true;
+    }
+
+    private function addTitleToMarkup(string $markup, ?string $title): string
+    {
+        if (null === $title) {
+            return $markup;
+        }
+
+        return preg_replace('/(<svg(.|\n)*?>\n?)/', "$1<title>$title</title>", $markup);
+    }
 }
 
-
+class IconNotFound extends Exception {};