Add str_increment and str_decrement functions

Author: Fan2Shrek

src/Php83/Php83.php

@@ -12,7 +12,7 @@
 namespace Symfony\Polyfill\Php83;
 
 /**
- * @author Ion Bazan <ion.bazan@gmail.com>
+ * @author Ion Bazan <ion.bazan@gmail.com>, Pierre Ambroise <pierre27.ambroise@gmail.com>
  *
  * @internal
  */
@@ -82,4 +82,42 @@ public static function mb_str_pad(string $string, int $length, string $pad_strin
                 return mb_substr(str_repeat($pad_string, $leftPaddingLength), 0, $leftPaddingLength, $encoding).$string.mb_substr(str_repeat($pad_string, $rightPaddingLength), 0, $rightPaddingLength, $encoding);
         }
     }
+
+    public static function str_increment(string $string): string
+    {
+        if ('' === $string) {
+            throw new \ValueError('str_increment(): Argument #1 ($string) cannot be empty');
+        }
+
+        if (1 === preg_match('/[^\x00-\x7F]/', $string)) {
+            throw new \ValueError('str_increment(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters');
+        }
+
+        return ++$string;
+    }
+
+    public static function str_decrement(string $string): string
+    {
+        if ('' === $string) {
+            throw new \ValueError('str_decrement(): Argument #1 ($string) cannot be empty');
+        }
+
+        if (1 === preg_match('/[^\x00-\x7F]/', $string)) {
+            throw new \ValueError('str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters');
+        }
+        
+        if ($string === 'A' || $string === '0') {
+            throw new \ValueError(sprintf('Argument #1 ($string) "%s" is out of decrement range', $string));
+        }
+
+        if (!in_array(substr($string, -1), ['A', '0'])){
+            return join('', array_slice(str_split($string), 0, -1)) . chr(ord(substr($string, -1)) - 1);
+        }
+    
+        if (strlen($string) === 1) {
+            return '';
+        }
+    
+        return self::str_decrement(substr($string, 0, -1)) . 'Z';
+    }
 }

src/Php83/bootstrap.php

@@ -27,6 +27,14 @@ function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $
     function stream_context_set_options($context, array $options): bool { return stream_context_set_option($context, $options); }
 }
 
+if (!function_exists('str_increment')) {
+    function str_increment(string $string): string { return p\Php83::str_increment($string); }
+}
+
+if (!function_exists('str_decrement')) {
+    function str_decrement(string $string): string { return p\Php83::str_decrement($string); }
+}
+
 if (\PHP_VERSION_ID >= 80100) {
     return require __DIR__.'/bootstrap81.php';
 }

tests/Php83/Php83Test.php

@@ -46,7 +46,7 @@ public function testMbStrPad(string $expectedResult, string $string, int $length
     public function testMbStrPadInvalidArguments(string $expectedError, string $string, int $length, string $padString, int $padType, string $encoding = null): void
     {
         $this->expectException(\ValueError::class);
-        $this->expectErrorMessage($expectedError);
+        $this->expectExceptionMessage($expectedError);
 
         mb_str_pad($string, $length, $padString, $padType, $encoding);
     }
@@ -161,7 +161,7 @@ public static function jsonDataProvider(): iterable
     public function testJsonValidateInvalidOptionsProvided(int $depth, int $flags, string $expectedError)
     {
         $this->expectException(\ValueError::class);
-        $this->expectErrorMessage($expectedError);
+        $this->expectExceptionMessage($expectedError);
         json_validate('{}', $depth, $flags);
     }
 
@@ -202,4 +202,66 @@ public function testDateTimeExceptionClassesExist()
         $this->assertTrue(class_exists(\DateMalformedIntervalStringException::class));
         $this->assertTrue(class_exists(\DateMalformedPeriodStringException::class));
     }
+
+    /** 
+     * @dataProvider strIncrementProvider
+     */
+    public function testStrIncrement(string $result, string $string)
+    {
+        $this->assertSame($result, str_increment($string));
+    }
+
+    /**
+     * @dataProvider strIncrementProvider
+     */
+    public function testStrDecrements(string $string, string $result)
+    {
+        $this->assertSame($result, str_decrement($string));
+    }
+    
+    public static function strIncrementProvider(): iterable
+    {
+        yield ['ABD', 'ABC'];
+        yield ['EB', 'EA'];
+        yield ['AAA', 'ZZ'];
+        yield ['AAA2', 'AAA1'];
+    }
+
+    /**
+     * @dataProvider strInvalidIncrementProvider
+     */
+    public function testInvalidStrIncrements(string $errorMessage, string $string)
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage($errorMessage);
+
+        str_increment($string);
+    }
+
+
+    public static function strInvalidIncrementProvider(): iterable
+    {
+        yield ['str_increment(): Argument #1 ($string) cannot be empty', ""];
+        yield ['str_increment(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters', '我喜歡雞肉'];
+        yield ['str_increment(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters', '書左'];
+    }
+
+
+    /**
+     * @dataProvider strInvalidDecrementProvider
+     */
+    public function testInvalidStrDecrements(string $errorMessage, string $string)
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage($errorMessage);
+
+        str_decrement($string);
+    }
+
+    public static function strInvalidDecrementProvider(): iterable
+    {
+        yield ['str_decrement(): Argument #1 ($string) cannot be empty', ''];
+        yield ['str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters', '我喜歡雞肉'];
+        yield ['str_decrement(): Argument #1 ($string) "A" is out of decrement range', 'A'];
+    }
 }