Allow injecting validate.js options

It's now possible to set up a static `validatorOptions` object in the stimulus
controller. This object will be used to pass any extra options accepted by validate.js.

Eg, validate.js has an option to skip prepending the error msgs with the attr name: `fullMessages`.
When setting this option to false, instead of an error msg being "Foo can't be blank", it'll be
"can't be blank".

It's now easy to pass this option by setting:

   static rules = {...}
   static validatorOptions = { fullMessages: false }

---

Author: dferrazm

spec/validator_spec.js

@@ -25,6 +25,9 @@ describe("Validator", function() {
         rules: {
           name: { presence: { allowEmpty: false } },
           email: { presence: { allowEmpty: false }, email: true }
+        },
+        validatorOptions: {
+          fullMessages: false
         }
       }
     }
@@ -127,7 +130,8 @@ describe("Validator", function() {
       it("returns validatajs params", function() {
         const params = [
           { name: "" },
-          { name: { presence: { allowEmpty: false } } }
+          { name: { presence: { allowEmpty: false } } },
+          { fullMessages: false }
         ]
 
         expect(this.validator.validatejsParams("name")).to.eql(params)

src/validator.js

@@ -53,13 +53,21 @@ export class Validator {
     }
 
     const { value } = this.attributes.get(attribute)
-    return [{ [attribute]: value }, { [attribute]: this.rules[attribute] }]
+    return [
+      { [attribute]: value },
+      { [attribute]: this.rules[attribute] },
+      this.validatorOptions || {}
+    ]
   }
 
   get rules() {
     return this.controller.constructor.rules
   }
 
+  get validatorOptions() {
+    return this.controller.constructor.validatorOptions
+  }
+
   get errors() {
     return this.controller.errors
   }