fix(testing): Make Testing TextProcessing providers unicode safe

Signed-off-by: Marcel Klehr <[email protected]>

apps/testing/lib/Provider/FakeTextProcessingProvider.php

@@ -18,10 +18,24 @@ public function getName(): string {
 	}
 
 	public function process(string $prompt): string {
-		return strrev($prompt) . ' (done with FakeTextProcessingProvider)';
+		return $this->mb_strrev($prompt) . ' (done with FakeTextProcessingProvider)';
 	}
 
 	public function getTaskType(): string {
 		return FreePromptTaskType::class;
 	}
+
+	/**
+	 * Reverse a miltibyte string.
+	 *
+	 * @param string $string The string to be reversed.
+	 * @param string|null $encoding The character encoding. If it is omitted, the internal character encoding value
+	 *     will be used.
+	 * @return string The reversed string
+	 */
+	private function mb_strrev(string $string, string $encoding = null): string
+	{
+		$chars = mb_str_split($string, 1, $encoding ?: mb_internal_encoding());
+		return implode('', array_reverse($chars));
+	}
 }

apps/testing/lib/Provider/FakeTextProcessingProviderSync.php

@@ -20,7 +20,7 @@ public function getName(): string {
 	}
 
 	public function process(string $prompt): string {
-		return strrev($prompt) . ' (done with FakeTextProcessingProviderSync)';
+		return $this->mb_strrev($prompt) . ' (done with FakeTextProcessingProviderSync)';
 	}
 
 	public function getTaskType(): string {
@@ -30,4 +30,18 @@ public function getTaskType(): string {
 	public function getExpectedRuntime(): int {
 		return 1;
 	}
+
+	/**
+	 * Reverse a miltibyte string.
+	 *
+	 * @param string $string The string to be reversed.
+	 * @param string|null $encoding The character encoding. If it is omitted, the internal character encoding value
+	 *     will be used.
+	 * @return string The reversed string
+	 */
+	private function mb_strrev(string $string, string $encoding = null): string
+	{
+		$chars = mb_str_split($string, 1, $encoding ?: mb_internal_encoding());
+		return implode('', array_reverse($chars));
+	}
 }