Added Japanese support for getting string length. (#1)

* fix: Added Japanese support for getting str length
* add: text test
* fix: code style
* add: require mbstring
* fix: use utf-8

Author: fuwasegu

composer.json

@@ -8,7 +8,8 @@
     },
     "require": {
         "php": ">=7.3",
-        "ext-json": "*"
+        "ext-json": "*",
+        "ext-mbstring": "*"
     },
     "require-dev": {
         "phpstan/phpstan": "^0.12.0",

src/Inputs/HasPlaceholder.php

@@ -29,7 +29,7 @@ public function setPlaceholder(PlainText $placeholder): self
      */
     public function placeholder(string $placeholder): self
     {
-        if (strlen($placeholder) > 150) {
+        if (mb_strlen($placeholder, 'UTF-8') > 150) {
             throw new Exception('Placeholder cannot exceed 150 characters');
         }
 

src/Partials/Text.php

@@ -51,11 +51,11 @@ public static function validateString(?string $text, ?int $max = null, int $min
             throw new Exception('Text element must have a "text" value');
         }
 
-        if (strlen($text) < $min) {
+        if (mb_strlen($text, 'UTF-8') < $min) {
             throw new Exception('Text element must have a "text" value with a length of at least %d', [$min]);
         }
 
-        if (is_int($max) && strlen($text) > $max) {
+        if (is_int($max) && mb_strlen($text, 'UTF-8') > $max) {
             throw new Exception('Text element must have a "text" value with a length of at most %d', [$max]);
         }
     }

tests/Partials/TextTest.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SlackPhp\BlockKit\Tests\Partials;
+
+use SlackPhp\BlockKit\Exception;
+use SlackPhp\BlockKit\Partials\Text;
+use SlackPhp\BlockKit\Tests\TestCase;
+
+/**
+ * @covers \SlackPhp\BlockKit\Partials\Text
+ */
+class TextTest extends TestCase
+{
+    private const MAX_LENGTH = 5;
+    private const MIN_LENGTH = 2;
+
+    public function testCanValidateEnglishText()
+    {
+        $text = new class () extends Text {
+        };
+
+        $text->validateString('abc', self::MAX_LENGTH);
+
+        $this->expectException(Exception::class);
+
+        $this->expectExceptionMessage('Text element must have a "text" value with a length of at most 5');
+        $text->validateString('abcdefg', self::MAX_LENGTH);
+
+        $this->expectExceptionMessage('Text element must have a "text" value with a length of at least 2');
+        $text->validateString('a', self::MAX_LENGTH, self::MIN_LENGTH);
+    }
+
+    public function testCanValidateJapaneseText()
+    {
+        $text = new class () extends Text {
+        };
+
+        $text->validateString('いろは', self::MAX_LENGTH);
+
+        $this->expectException(Exception::class);
+
+        $this->expectExceptionMessage('Text element must have a "text" value with a length of at most 5');
+        $text->validateString('いろはにほへと', self::MAX_LENGTH);
+
+        $this->expectExceptionMessage('Text element must have a "text" value with a length of at least 2');
+        $text->validateString('い', self::MAX_LENGTH, self::MIN_LENGTH);
+    }
+}