Add error types parser

This parser converts an error types expression from string to integer.
e.g. E_ALL & ~E_DEPRECATED & ~E_NOTICE -> 24567

Author: d3f3kt

src/Sentry/SentryBundle/ErrorTypesParser.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace Sentry\SentryBundle;
+
+/**
+ * Evaluate an error types expression.
+ */
+class ErrorTypesParser
+{
+    private $expression = null;
+
+    /**
+     * Initialize ErrorParser
+     *
+     * @param string $expression Error Types e.g. E_ALL & ~E_DEPRECATED & ~E_NOTICE
+     */
+    public function __construct($expression)
+    {
+        $this->expression = $expression;
+    }
+
+    /**
+     * Parse and compute the error types expression
+     *
+     * @return int the parsed expression
+     */
+    public function parse()
+    {
+        // convert constants to ints
+        $this->expression = $this->convertErrorConstants($this->expression);
+        $this->expression = str_replace([",", " "], [".", ""], $this->expression);
+        // remove anything which could be a security issue
+        $this->expression = preg_replace("/[^\d.+*%^|&~<>\/()-]/", "", $this->expression);
+
+        return $this->compute($this->expression);
+    }
+
+
+    /**
+     * Converts error constants from string to int.
+     *
+     * @param  string $expression e.g. E_ALL & ~E_DEPRECATED & ~E_NOTICE
+     * @return string   convertes expression e.g. 32767 & ~8192 & ~8
+     */
+    private function convertErrorConstants($expression)
+    {
+        $output = preg_replace_callback("/(E_[a-zA-Z_]+)/", function ($errorConstant) {
+            if (defined($errorConstant[1])) {
+                return constant($errorConstant[1]);
+            }
+            return $errorConstant[0];
+        }, $expression);
+
+        return $output;
+    }
+
+    /**
+     * Let PHP compute the prepared expression for us.
+     * 
+     * @param  string $expression prepared expression e.g. 32767&~8192&~8
+     * @return int  computed expression e.g. 24567
+     */
+    private function compute($expression)
+    {
+        $compute = create_function("", "return " . $expression . ";");
+
+        return 0 + $compute();
+    }
+}

test/Sentry/SentryBundle/Test/ErrorTypesParserTest.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Sentry\SentryBundle\Test;
+
+use Sentry\SentryBundle\ErrorTypesParser;
+
+class ErrorTypesParserTest extends \PHPUnit_Framework_TestCase
+{
+    public function test_error_types_parser()
+    {
+        $ex = new ErrorTypesParser('E_ALL & ~E_DEPRECATED & ~E_NOTICE');
+        $this->assertEquals($ex->parse(), E_ALL & ~E_DEPRECATED & ~E_NOTICE);
+    }
+}