Add CHECK_MODE_REQUIRE_DEFAULTS

If CHECK_MODE_REQUIRE_DEFAULTS is set, then only apply defaults
if they are marked as required.

Author: erayd

README.md

@@ -187,6 +187,7 @@ third argument to `Validator::validate()`, or can be provided as the third argum
 | `Constraint::CHECK_MODE_TYPE_CAST` | Enable fuzzy type checking for associative arrays and objects |
 | `Constraint::CHECK_MODE_COERCE_TYPES` | Convert data types to match the schema where possible |
 | `Constraint::CHECK_MODE_APPLY_DEFAULTS` | Apply default values from the schema if not set |
+| `Constraint::CHECK_MODE_REQUIRE_DEFAULTS` | Only apply defaults when they are required |
 | `Constraint::CHECK_MODE_EXCEPTIONS` | Throw an exception immediately if validation fails |
 
 Please note that using `Constraint::CHECK_MODE_COERCE_TYPES` or `Constraint::CHECK_MODE_APPLY_DEFAULTS`

src/JsonSchema/Constraints/Constraint.php

@@ -30,6 +30,7 @@ abstract class Constraint extends BaseConstraint implements ConstraintInterface
     const CHECK_MODE_COERCE_TYPES =     0x00000004;
     const CHECK_MODE_APPLY_DEFAULTS =   0x00000008;
     const CHECK_MODE_EXCEPTIONS =       0x00000010;
+    const CHECK_MODE_REQUIRE_DEFAULTS = 0x00000020;
 
     /**
      * Bubble down the path

src/JsonSchema/Constraints/UndefinedConstraint.php

@@ -113,9 +113,23 @@ protected function validateCommonProperties(&$value, $schema = null, JsonPointer
         // Apply default values from schema
         if ($this->factory->getConfig(self::CHECK_MODE_APPLY_DEFAULTS)) {
             if (isset($schema->properties) && LooseTypeCheck::isObject($value)) {
+                $v4Required = isset($schema->required) ? $schema->required : array();
                 // $value is an object or assoc array, and properties are defined - treat as an object
                 foreach ($schema->properties as $currentProperty => $propertyDefinition) {
                     if (!LooseTypeCheck::propertyExists($value, $currentProperty) && isset($propertyDefinition->default)) {
+                        // Don't apply non-required defaults if running in required-only mode
+                        if (
+                            $this->factory->getConfig(self::CHECK_MODE_REQUIRE_DEFAULTS) &&
+                            !in_array($currentProperty, $v4Required, true) && // draft-04 required
+                            !(// draft-03 required
+                                isset($propertyDefinition->required) &&
+                                !is_array($propertyDefinition->required) &&
+                                $propertyDefinition->required
+                            )
+                        ) {
+                            continue;
+                        }
+                        // assign default value
                         if (is_object($propertyDefinition->default)) {
                             LooseTypeCheck::propertySet($value, $currentProperty, clone $propertyDefinition->default);
                         } else {

tests/Constraints/DefaultPropertiesTest.php

@@ -164,4 +164,37 @@ public function testLeaveBasicTypesAlone()
         $schema = json_decode('{"items":[{"type":"string","default":"valueOne"}]}');
         $this->assertEquals('"ThisIsAString"', json_encode($input));
     }
+
+    public function testRequiredOnlyDraft04()
+    {
+        $input = json_decode('{}');
+        $schema = json_decode('{
+            "properties": {
+                "propertyOne": {"default": "valueOne"},
+                "propertyTwo": {"default": "valueTwo"}
+            },
+            "required": ["propertyTwo"]
+        }');
+
+        $validator = new Validator();
+        $validator->validate($input, $schema, Constraint::CHECK_MODE_APPLY_DEFAULTS | Constraint::CHECK_MODE_REQUIRE_DEFAULTS);
+
+        $this->assertEquals('{"propertyTwo":"valueTwo"}', json_encode($input));
+    }
+
+    public function testRequiredOnlyDraft03()
+    {
+        $input = json_decode('{}');
+        $schema = json_decode('{
+            "properties": {
+                "propertyOne": {"default": "valueOne"},
+                "propertyTwo": {"default": "valueTwo", "required": true}
+            }
+        }');
+
+        $validator = new Validator();
+        $validator->validate($input, $schema, Constraint::CHECK_MODE_APPLY_DEFAULTS | Constraint::CHECK_MODE_REQUIRE_DEFAULTS);
+
+        $this->assertEquals('{"propertyTwo":"valueTwo"}', json_encode($input));
+    }
 }