feat: add StringUtil::removeZeroWidthCharacters

src/StringUtil.php

@@ -99,6 +99,12 @@ public static function normalizeLineEndings(string $input, string $to = self::WI
         return \Safe\preg_replace("/\r\n|\r|\n/", $to, $input);
     }
 
+    /** Removes U+200B to U+200D and U+FEFF, which text pasted from mails or web pages often carries. */
+    public static function removeZeroWidthCharacters(string $input): string
+    {
+        return \Safe\preg_replace('/[\x{200B}-\x{200D}\x{FEFF}]/u', '', $input);
+    }
+
     /** Convert string that could be in different UTF encodings (UTF-8, UTF-16BE, ...) to UTF-8. */
     public static function toUTF8(string $string): string
     {

tests/StringUtilTest.php

@@ -89,6 +89,14 @@ public function testNormalizeLineEndings(): void
         );
     }
 
+    public function testRemoveZeroWidthCharacters(): void
+    {
+        self::assertSame(
+            'für dringende Anliegen',
+            StringUtil::removeZeroWidthCharacters("für drin\u{200B}gende\u{200C} An\u{200D}liegen\u{FEFF}")
+        );
+    }
+
     public function testUTF8(): void
     {
         $expectedUTF8 = 'test';