JsonValidator

JsonValidator.groovy

class JsonValidator extends BuilderSupport {
  def root = null
  
  void setParent(Object parent, Object child) {
    if (!root) root = parent
    parent.children << child
  }
  void createNode(Object name, Map attributes, Object value) {
    return [name: name, value: value, children: []]
  }
  
  String validate(Object value) {
    return validate(root, value, '')
  }
  
  private String validate(Object schema, Object value, String prefix) {
    if (!value) return "$prefix.$schema.name is null"
    def result = new StringBuilder()
    schema.children.each {
      def propertyType = it.value
      def propertyName = it.name
      def propertyValue = value[propertyName]
      if (propertyType) {
        if (!propertyValue)
          result.append("\n$prefix.").append "$propertyName not found"
        else if (propertyValue.class != propertyType)
          result.append("\n$prefix.").append "$propertyName has wrong type: $propertyValue, should be $propertyType"
      } else
        result.append(validate(it, propertyValue, "$prefix.$propertyName"))
    }
    return result.toString()
  }
}

class JsonValidatorTest {
  
  def schema
  
  @Before
  void setup() {
    schema = new JsonValidator()
    schema.build() {
      password String
      url String
      props {
        age Integer
        nonsence Boolean
      }
    }
  }
  
  @Test
  void testPositive() {
    assert schema.validate('''
{"password":"123","url":"http:lalla", "props":{"age":13, "nonsence":true}}
''').isEmpty()
  }

  @Test
  void testTypeMismatch() {
    assert schema.validate('''
{"password":"123","url":"http:lalla", "props":{"age":13, "nonsence":"true"}}
''') == '.props.nonsence has wrong type class java.lang.String: should be class java.lang.Boolean'
  }

  @Test
  void testPropertyMissing() {
    assert schema.validate('''
{"password":"123","url":"http:lalla", "props":{"age":13}}
''') == '.props.nonsence not found'
  }
}