fix: Language does not throw exception

We have code like this:
  throw PageNotFoundException::forMethodNotFound($this->method);
and
  public static function forMethodNotFound(string $method)
  {
      return new static(self::lang('HTTP.methodNotFound', [$method]));
  }
If Language throws an Exception, the first Exception will be hidden
in the error message.

Author: kenjis

system/Language/Language.php

@@ -12,7 +12,7 @@
 namespace CodeIgniter\Language;
 
 use Config\Services;
-use InvalidArgumentException;
+use IntlException;
 use MessageFormatter;
 
 /**
@@ -194,9 +194,26 @@ protected function formatMessage($message, array $args = [])
 
         $formatted = MessageFormatter::formatMessage($this->locale, $message, $args);
         if ($formatted === false) {
-            throw new InvalidArgumentException(
-                lang('Language.invalidMessageFormat', [$message, implode(',', $args)])
+            // Format again to get the error message.
+            try {
+                $fmt       = new MessageFormatter($this->locale, $message);
+                $formatted = $fmt->format($args);
+                $fmtError  = '"' . $fmt->getErrorMessage() . '" (' . $fmt->getErrorCode() . ')';
+            } catch (IntlException $e) {
+                $fmtError = '"' . $e->getMessage() . '" (' . $e->getCode() . ')';
+            }
+
+            $argsString = implode(',', $args);
+
+            log_message(
+                'error',
+                'Language.invalidMessageFormat: $message: "' . $message
+                . '", $args: "' . $argsString . '"'
+                . ' (urlencoded: ' . rawurlencode($argsString) . '),'
+                . ' MessageFormatter Error: ' . $fmtError
             );
+
+            return $message . "\n【Warning】Also, invalid string(s) was passed to the Language class. See log file for details.";
         }
 
         return $formatted;

tests/system/Language/LanguageTest.php

@@ -14,7 +14,6 @@
 use CodeIgniter\Test\CIUnitTestCase;
 use CodeIgniter\Test\Mock\MockLanguage;
 use Config\Services;
-use InvalidArgumentException;
 use MessageFormatter;
 use Tests\Support\Language\SecondMockLanguage;
 
@@ -137,18 +136,14 @@ public function testGetLineInvalidFormatMessage(): void
             $this->markTestSkipped('No intl support.');
         }
 
-        $this->expectException(InvalidArgumentException::class);
-        $this->expectExceptionMessage(
-            'Invalid message format: "تم الكشف عن كلمة المرور {0} بسبب اختراق البيانات وشوهدت {1 ، عدد} مرة في {2} في كلمات المرور المخترقة.", args: "password,hits,wording"'
-        );
-
         $this->lang->setLocale('ar');
 
-        $this->lang->setData('Auth', [
-            'errorPasswordPwned' => 'تم الكشف عن كلمة المرور {0} بسبب اختراق البيانات وشوهدت {1 ، عدد} مرة في {2} في كلمات المرور المخترقة.',
-        ]);
+        $line = 'تم الكشف عن كلمة المرور {0} بسبب اختراق البيانات وشوهدت {1 ، عدد} مرة في {2} في كلمات المرور المخترقة.';
+        $this->lang->setData('Auth', ['errorPasswordPwned' => $line]);
+
+        $output = $this->lang->getLine('Auth.errorPasswordPwned', ['password', 'hits', 'wording']);
 
-        $this->lang->getLine('Auth.errorPasswordPwned', ['password', 'hits', 'wording']);
+        $this->assertSame($line . "\n【Warning】Also, invalid string(s) was passed to the Language class. See log file for details.", $output);
     }
 
     /**