Improve properties of ValidationError

- change `statusCode` from 400 to 422
- nest `context` and `codes` inside `details`
- add `details.messages`
- reword the main error message

Remove the call to Error's constructor from ValidationError constructor,
because it's a no-op - Error's constructor creates a new
instance when called via `.call()`.

index.js

@@ -4,6 +4,7 @@ exports.ModelBuilder = exports.LDL = require('./lib/model-builder.js').ModelBuil
 exports.DataSource = exports.Schema = require('./lib/datasource.js').DataSource;
 exports.ModelBaseClass = require('./lib/model.js');
 exports.Connector = require('./lib/connector.js');
+exports.ValidationError = require('./lib/validations.js').ValidationError;
 
 var baseSQL = './lib/sql';
 

lib/validations.js

@@ -599,12 +599,16 @@ function ValidationError(obj) {
     if (!(this instanceof ValidationError)) return new ValidationError(obj);
 
     this.name = 'ValidationError';
-    this.message = 'Validation error';
+    this.message = 'The Model instance is not valid. ' +
-    this.statusCode = 400;
+      'See `details` property of the error object for more info.';
-    this.codes = obj.errors && obj.errors.codes;
+    this.statusCode = 422;
-    this.context = obj && obj.constructor && obj.constructor.modelName;
+
+    this.details = {
+      context: obj && obj.constructor && obj.constructor.modelName,
+      codes: obj.errors && obj.errors.codes,
+      messages: obj.errors
+    };
 
-    Error.call(this);
     Error.captureStackTrace(this, this.constructor);
 }
 

test/manipulation.test.js

@@ -2,6 +2,7 @@
 var should = require('./init.js');
 
 var db, Person;
+var ValidationError = require('..').ValidationError;
 
 describe('manipulation', function() {
 
@@ -173,7 +174,7 @@ describe('manipulation', function() {
                     p.save({
                         'throws': true
                     });
-                }).should.throw('Validation error');
+                }).should.throw(ValidationError);
             });
         });
 

test/validations.test.js

@@ -2,7 +2,7 @@
 var should = require('./init.js');
 
 var j = require('../'), db, User;
-var ValidationError = require('../lib/validations.js').ValidationError;
+var ValidationError = j.ValidationError;
 
 function getValidAttributes() {
     return {
@@ -98,7 +98,7 @@ describe('validations', function() {
                 User.validatesPresenceOf('name');
                 User.create(function(e, u) {
                     should.exist(e);
-                    e.codes.name.should.eql(['presence']);
+                    e.details.codes.name.should.eql(['presence']);
                     done();
                 });
             });