[console] Add truncate method to FormatterHelper

Author: marek-pietrzak-tg

src/Symfony/Component/Console/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+3.1.0
+-----
+
+ * added truncate method to FormatterHelper
+
 2.8.0
 -----
 

src/Symfony/Component/Console/Helper/FormatterHelper.php

@@ -72,6 +72,30 @@ public function formatBlock($messages, $style, $large = false)
         return implode("\n", $messages);
     }
 
+    /**
+     * Truncates a message to the given length.
+     *
+     * @param string $message
+     * @param int    $length
+     * @param string $suffix
+     *
+     * @return string
+     */
+    public function truncate($message, $length, $suffix = '...')
+    {
+        $computedLength = $length - $this->strlen($suffix);
+
+        if ($computedLength > $this->strlen($message)) {
+            return $message;
+        }
+
+        if (false === $encoding = mb_detect_encoding($message, null, true)) {
+            return substr($message, 0, $length).$suffix;
+        }
+
+        return mb_substr($message, 0, $length, $encoding).$suffix;
+    }
+
     /**
      * {@inheritdoc}
      */

src/Symfony/Component/Console/Tests/Helper/FormatterHelperTest.php

@@ -89,4 +89,40 @@ public function testFormatBlockLGEscaping()
             '::formatBlock() escapes \'<\' chars'
         );
     }
+
+    public function testTruncatingWithShorterLengthThanMessageWithSuffix()
+    {
+        $formatter = new FormatterHelper();
+        $message = 'testing truncate';
+
+        $this->assertSame('test...', $formatter->truncate($message, 4));
+        $this->assertSame('testing truncat...', $formatter->truncate($message, 15));
+        $this->assertSame('testing truncate...', $formatter->truncate($message, 16));
+        $this->assertSame('zażółć gęślą...', $formatter->truncate('zażółć gęślą jaźń', 12));
+    }
+
+    public function testTruncatingMessageWithCustomSuffix()
+    {
+        $formatter = new FormatterHelper();
+        $message = 'testing truncate';
+
+        $this->assertSame('test!', $formatter->truncate($message, 4, '!'));
+    }
+
+    public function testTruncatingWithLongerLengthThanMessageWithSuffix()
+    {
+        $formatter = new FormatterHelper();
+        $message = 'test';
+
+        $this->assertSame($message, $formatter->truncate($message, 10));
+    }
+
+    public function testTruncatingWithNegativeLength()
+    {
+        $formatter = new FormatterHelper();
+        $message = 'testing truncate';
+
+        $this->assertSame('testing tru...', $formatter->truncate($message, -5));
+        $this->assertSame('...', $formatter->truncate($message, -100));
+    }
 }