minor #3687 throwing syntax error when the matches regexp is not vali…

…d (WebMamba, fabpot)

This PR was merged into the 3.x branch.

Discussion
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throwing syntax error when the matches regexp is not valid

During the symfony live, Fabien talk about a PR he did on the Expression Language component (https://github.com/symfony/symfony/pull/45875/files). The goal was to throw a more readable error when using the matchs operator. This think need to be fix in twig to. So as promises, here is my PR !
This is my first contrib to symfony so any advice is welcome ! 😁

Commits
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a82e94d Add some tests
61672c4 throwing syntaxt error when the matches regexp is not valid

src/Extension/CoreExtension.php

@@ -1019,6 +1019,26 @@ function twig_compare($a, $b)
     return $a <=> $b;
 }
 
+/**
+ * @param string $pattern
+ * @param string $subject
+ *
+ * @return int
+ *
+ * @throws RuntimeError When an invalid pattern is used
+ */
+function twig_matches(string $regexp, string $str)
+{
+    set_error_handler(function ($t, $m) use ($regexp) {
+        throw new RuntimeError(sprintf('Regexp "%s" passed to "matches" is not valid', $regexp).substr($m, 12));
+    });
+    try {
+        return preg_match($regexp, $str);
+    } finally {
+        restore_error_handler();
+    }
+}
+
 /**
  * Returns a trimmed string.
  *

src/Node/Expression/Binary/MatchesBinary.php

@@ -18,7 +18,7 @@ class MatchesBinary extends AbstractBinary
     public function compile(Compiler $compiler): void
     {
         $compiler
-            ->raw('preg_match(')
+            ->raw('twig_matches(')
             ->subcompile($this->getNode('right'))
             ->raw(', ')
             ->subcompile($this->getNode('left'))

tests/Fixtures/expressions/matches_error.test

@@ -0,0 +1,8 @@
+--TEST--
+Twig supports the "matches" operator with a great error message
+--TEMPLATE--
+{{ 'foo' matches '/o' }}
+--DATA--
+return []
+--EXCEPTION--
+Twig\Error\RuntimeError: Regexp "/o" passed to "matches" is not valid: No ending delimiter '/' found in "index.twig" at line 2