Exclude trace from exceptions/errors for performance reasons (#24)

README.md

@@ -22,7 +22,6 @@ Exception Object &0000000078de0f0d000000002003a261 (
     'code' => 0
     'file' => '/home/sebastianbergmann/test.php'
     'line' => 34
-    'trace' => Array &0 ()
     'previous' => null
 )
 */

src/Exporter.php

@@ -146,6 +146,13 @@ class Exporter
         $array = [];
 
         foreach ((array) $value as $key => $val) {
+            // Exception traces commonly reference hundreds to thousands of
+            // objects currently loaded in memory. Including them in the result
+            // has a severe negative performance impact.
+            if ("\0Error\0trace" === $key || "\0Exception\0trace" === $key) {
+                continue;
+            }
+
             // properties are transformed to keys in the following way:
             // private   $property => "\0Classname\0property"
             // protected $property => "\0*\0property"

tests/ExporterTest.php

@@ -168,6 +168,32 @@ EOF
                 '',
                 "''"
             ],
+            'export Exception without trace' => [
+                new \Exception('The exception message', 42),
+                <<<EOF
+Exception Object &%x (
+    'message' => 'The exception message'
+    'string' => ''
+    'code' => 42
+    'file' => '%s/tests/ExporterTest.php'
+    'line' => %d
+    'previous' => null
+)
+EOF
+            ],
+            'export Error without trace' => [
+                new \Error('The exception message', 42),
+                <<<EOF
+Error Object &%x (
+    'message' => 'The exception message'
+    'string' => ''
+    'code' => 42
+    'file' => '%s/tests/ExporterTest.php'
+    'line' => %d
+    'previous' => null
+)
+EOF
+            ],
         ];
     }