allow empty values when optional

lib/schema/__test__/validator.test.js

@@ -58,6 +58,26 @@ describe('validator(field, config)', () => {
     expect(result).toBeInstanceOf(Date)
   })
 
+  it('should return the value if it is undefined and not required and a default is not set', () => {
+    delete config.required
+    delete config.default
+
+    const validate = validator('string', config)
+    const result = validate(null)
+
+    expect(result).toBeNull()
+  });
+
+  it('should return the value if it is an emum, undefined and not required and a default is not set', () => {
+    delete ofConfig.required
+
+    const validate = validator('enum', ofConfig)
+    const result = validate(null)
+
+    expect(result).toBeNull()
+  });
+
+
   it('should return error when default is different than type', () => {
     const badConfig = {
       required: true,

lib/schema/validator.js

@@ -32,10 +32,16 @@ const functionizeConfig = (field, config) => {
     _config.default = always(config.default)
   }
   if (config.enum) {
+
     _config.enum = value => {
+      // Don't validate enums if they are optional and not set
+      if (!config.required && (value === undefined || value === null)) {
+        return value
+      } 
+
       if (!contains(value, config.enum)) {
         throw new Error(
-          `Field ${field} only accpets [ ${config.enum.join(', ')} ]. Instead got ${value}`
+          `Field ${field} only accepts [ ${config.enum.join(', ')} ]. Instead got ${value}`
         )
       } else {
         return value
@@ -44,6 +50,11 @@ const functionizeConfig = (field, config) => {
   }
   if (config.type) {
     _config.type = value => {
+      // Don't validate the value if it is optional and not set
+      if (!config.required && (value === undefined || value === null)) {
+        return value
+      } 
+
       const type = valid[config.type.toLowerCase()]
       const isValid = type(value)
       if (isValid !== null) {