From e2773e452491f2664d4ef0d11e2bb557c6d19112 Mon Sep 17 00:00:00 2001
From: Saleh Hashemi <81674631+salehhashemi1992@users.noreply.github.com>
Date: Wed, 25 Oct 2023 20:17:03 +0330
Subject: [PATCH] Fix #20032: Added `mask` method for string masking with
 multibyte support

---
 framework/CHANGELOG.md                       |  2 ++
 framework/helpers/BaseStringHelper.php       | 30 ++++++++++++++++++
 tests/framework/helpers/StringHelperTest.php | 32 ++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 69bcec2bd8..ec2923a1e5 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -11,6 +11,8 @@ Yii Framework 2 Change Log
 - Bug #20002: Fixed superfluous query on HEAD request in serializer (xicond)
 - Enh #12743: Added new methods `BaseActiveRecord::loadRelations()` and `BaseActiveRecord::loadRelationsFor()` to eager load related models for existing primary model instances (PowerGamer1)
 - Enh #20030: Improve performance of handling `ErrorHandler::$memoryReserveSize` (antonshevelev, rob006)
+- Enh #20032: Added `mask` method for string masking with multibyte support (salehhashemi1992)
+
 
 2.0.49.2 October 12, 2023
 -------------------------
diff --git a/framework/helpers/BaseStringHelper.php b/framework/helpers/BaseStringHelper.php
index 60261f9828..e9c5327b03 100644
--- a/framework/helpers/BaseStringHelper.php
+++ b/framework/helpers/BaseStringHelper.php
@@ -497,4 +497,34 @@ class BaseStringHelper
 
         return implode('', $parts);
     }
+
+    /**
+     * Masks a portion of a string with a repeated character.
+     * This method is multibyte-safe.
+     *
+     * @param string $string The input string.
+     * @param int $start The starting position from where to begin masking.
+     *                   This can be a positive or negative integer.
+     *                   Positive values count from the beginning,
+     *                   negative values count from the end of the string.
+     * @param int $length The length of the section to be masked.
+     *                    The masking will start from the $start position
+     *                    and continue for $length characters.
+     * @param string $mask The character to use for masking. The default is '*'.
+     * @return string The masked string.
+     */
+    public static function mask($string, $start, $length, $mask = '*') {
+        $strLength = mb_strlen($string, 'UTF-8');
+
+        // Return original string if start position is out of bounds
+        if ($start >= $strLength || $start < -$strLength) {
+            return $string;
+        }
+
+        $masked = mb_substr($string, 0, $start, 'UTF-8');
+        $masked .= str_repeat($mask, abs($length));
+        $masked .= mb_substr($string, $start + abs($length), null, 'UTF-8');
+
+        return $masked;
+    }
 }
diff --git a/tests/framework/helpers/StringHelperTest.php b/tests/framework/helpers/StringHelperTest.php
index 56acdb0c26..a640e5cdda 100644
--- a/tests/framework/helpers/StringHelperTest.php
+++ b/tests/framework/helpers/StringHelperTest.php
@@ -474,4 +474,36 @@ class StringHelperTest extends TestCase
             ['', ''],
         ];
     }
+
+    public function testMask()
+    {
+        // Standard masking
+        $this->assertSame('12******90', StringHelper::mask('1234567890', 2, 6));
+        $this->assertSame('a********j', StringHelper::mask('abcdefghij', 1, 8));
+        $this->assertSame('*************', StringHelper::mask('Hello, World!', 0, 13));
+        $this->assertSame('************!', StringHelper::mask('Hello, World!', 0, 12));
+        $this->assertSame('Hello, *orld!', StringHelper::mask('Hello, World!', 7, 1));
+        $this->assertSame('Saleh Hashemi', StringHelper::mask('Saleh Hashemi', 0, 0));
+
+        // Different Mask Character
+        $this->assertSame('12######90', StringHelper::mask('1234567890', 2, 6, '#'));
+
+        // Positions outside the string
+        $this->assertSame('1234567890', StringHelper::mask('1234567890', 20, 6));
+        $this->assertSame('1234567890', StringHelper::mask('1234567890', -20, 6));
+
+        // Negative values for start
+        $this->assertSame('1234****90', StringHelper::mask('1234567890', -6, 4));
+
+        // type-related edge case
+        $this->assertSame('1234****90', StringHelper::mask(1234567890, -6, 4));
+
+        // Multibyte characters
+        $this->assertSame('你**', StringHelper::mask('你好吗', 1, 2));
+        $this->assertSame('你好吗', StringHelper::mask('你好吗', 4, 2));
+
+        // Special characters
+        $this->assertSame('em**l@email.com', StringHelper::mask('email@email.com', 2, 2));
+        $this->assertSame('******email.com', StringHelper::mask('email@email.com', 0, 6));
+    }
 }