Fix tests for empty / null / false values when schema allows them

Author: justinrainbow

src/JsonSchema/Constraints/Object.php

@@ -38,7 +38,7 @@ public function validateElement($element, $objectDefinition = null, $path = null
             $definition = $this->getProperty($objectDefinition, $i);
 
             //required property
-            if ($this->getProperty($definition, 'required') && !$property) {
+            if ($this->getProperty($definition, 'required') && $property instanceof Undefined) {
                 $this->addError($path, "the property " . $i . " is required");
             }
 
@@ -91,8 +91,10 @@ protected function getProperty($element, $property, $fallback = null)
     {
         if (is_array($element) /*$this->checkMode == self::CHECK_MODE_TYPE_CAST*/) {
             return array_key_exists($property, $element) ? $element[$property] : $fallback;
-        } else {
-            return isset($element->$property) ? $element->$property : $fallback;
+        } else if (is_object($element)) {
+            return property_exists($element, $property) ? $element->$property : $fallback;
         }
+
+        return $fallback;
     }
 }

src/JsonSchema/Constraints/Schema.php

@@ -18,7 +18,7 @@ public function check($element, $schema = null, $path = null, $i = null)
         if ($schema !== null) {
             // passed schema
             $this->checkUndefined($element, $schema, '', '');
-        } elseif (isset($element->{$this->inlineSchemaProperty})) {
+        } else if (property_exists($element, $this->inlineSchemaProperty)) {
             // inline schema
             $this->checkUndefined($element, $element->{$this->inlineSchemaProperty}, '', '');
         } else {

src/JsonSchema/Constraints/Type.php

@@ -84,7 +84,7 @@ protected function validateType($value, $type)
             case 'any' :
                 return true;
             default:
-                throw new \InvalidArgumentException((is_object($value) ? 'object' : $value) . ' is a invalid type for ' . $type);
+                throw new \InvalidArgumentException((is_object($value) ? 'object' : $value) . ' is an invalid type for ' . $type);
         }
     }
 }