feat: add function to output registered languages

CHANGELOG.md

@@ -7,6 +7,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Added
+- Function to output registered languages
+
 ## [0.1.0] - 2024-01-28
 
 Initial preview release

README.md

@@ -15,6 +15,7 @@ An addition to the highlighting of code this Twig extension provides additional
 - [line numbers](#line-numbers)
 - [emphasize lines](#emphasize-lines)
 - [classes](#classes)
+- [list of available languages](#list-of-available-languages)
 
 > This package is in beta phase! You can use it already, but API might change.
 
@@ -170,3 +171,17 @@ Using both variants together results in the following HTML code:
 ```html
 <pre class="some-default-class some-special-class another-special-class"><code class="hljs plaintext">some text</code></pre>
 ```
+
+### List of available languages
+
+Sometimes it can be useful to provide a list of available languages. The function `codehighlight_languages()`
+is available to output such a list:
+
+```twig
+<ul>
+{% for language in codehighlight_languages() %}
+    <li>{{ language }}</li>
+{% endfor %}
+</ul>
+```
+

src/Extension.php

@@ -17,6 +17,7 @@
 use Psr\Log\NullLogger;
 use Twig\Extension\AbstractExtension;
 use Twig\TwigFilter;
+use Twig\TwigFunction;
 
 /**
  * @see \Brotkrueml\TwigCodeHighlight\Tests\ExtensionTest
@@ -49,6 +50,9 @@ public function __construct(
         }
     }
 
+    /**
+     * @return list<TwigFilter>
+     */
     public function getFilters(): array
     {
         return [
@@ -62,6 +66,19 @@ public function getFilters(): array
         ];
     }
 
+    /**
+     * @return list<TwigFunction>
+     */
+    public function getFunctions(): array
+    {
+        return [
+            new TwigFunction(
+                'codehighlight_languages',
+                $this->languages(...),
+            ),
+        ];
+    }
+
     private function highlight(
         string $code,
         ?string $language,
@@ -160,4 +177,15 @@ private function addEmphasizeLines(string $code): string
 
         return \implode("\n", $newLines);
     }
+
+    /**
+     * @return list<string>
+     */
+    private function languages(): array
+    {
+        $registeredLanguages = Highlighter::listRegisteredLanguages();
+        \sort($registeredLanguages);
+
+        return $registeredLanguages;
+    }
 }

tests/ExtensionTest.php

@@ -32,11 +32,17 @@ protected function setUp(): void
     }
 
     #[Test]
-    public function getNameReturnExtensionName(): void
+    public function registeredFiltersAreAvailable(): void
     {
         self::assertSame('codehighlight', $this->subject->getFilters()[0]->getName());
     }
 
+    #[Test]
+    public function registeredFunctionsAreAvailable(): void
+    {
+        self::assertSame('codehighlight_languages', $this->subject->getFunctions()[0]->getName());
+    }
+
     #[Test]
     #[DataProvider('providerForHighlightThroughTwigTemplate')]
     public function highlightThroughTwigTemplate(string $filterArguments, string $code, string $expected): void
@@ -322,4 +328,33 @@ public function instantiatedWithClassesAndClassesGivenViaFilter(): void
 
         self::assertSame('<pre class="some-default-class some-special-class"><code class="hljs plaintext">some text</code></pre>', $template->render());
     }
+
+    #[Test]
+    public function registeredLanguagesAreReturnedCorrectly(): void
+    {
+        $loader = new ArrayLoader([
+            'index' => <<<TEMPLATE
+{% for language in codehighlight_languages() %}
+{{ language }}
+{% endfor %}
+TEMPLATE,
+        ]);
+        $twig = new Environment($loader, [
+            'debug' => true,
+            'cache' => false,
+        ]);
+        $twig->addExtension($this->subject);
+
+        $template = $twig->load('index');
+
+        $actual = $template->render();
+        $actualAsArray = \explode("\n", $actual);
+
+        // Validate sorting
+        self::assertStringStartsWith('1c', $actualAsArray[0]);
+        self::assertStringEndsWith('zephir', $actualAsArray[\count($actualAsArray) - 2]);
+
+        // Validate random language is available
+        self::assertContains('php', $actualAsArray);
+    }
 }