From 529e40a099fdf21c753b3b0e87935ddcecdd65e2 Mon Sep 17 00:00:00 2001
From: paddymann <paddymann1@gmail.com>
Date: Tue, 17 Jan 2017 21:04:41 +0100
Subject: [PATCH 1/2] Pass through options to custom validators (Code only)

---
 lib/validations.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/validations.js b/lib/validations.js
index ae3d523cd..5487256b3 100644
--- a/lib/validations.js
+++ b/lib/validations.js
@@ -340,7 +340,8 @@ function validateCustom(attr, conf, err, options, done) {
     done = options;
     options = {};
   }
-  conf.customValidator.call(this, err, done);
+
+  conf.customValidator.call(this, err, done, options);
 }
 
 /*!

From 163e3a6c67c97ac6447205e806c475e509ca80c5 Mon Sep 17 00:00:00 2001
From: paddymann <paddymann1@gmail.com>
Date: Tue, 17 Jan 2017 21:05:07 +0100
Subject: [PATCH 2/2] Add support for custom validators to return promises

---
 lib/validations.js       | 14 +++++++++++++-
 test/validations.test.js | 11 +++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/validations.js b/lib/validations.js
index 5487256b3..879a74fe3 100644
--- a/lib/validations.js
+++ b/lib/validations.js
@@ -341,7 +341,19 @@ function validateCustom(attr, conf, err, options, done) {
     options = {};
   }
 
-  conf.customValidator.call(this, err, done, options);
+  if (conf.customValidator.length <= 1) {
+    conf.customValidator.call(this, options)
+      .then((isValid) => {
+        if (!isValid) throw new Error();
+        done();
+      })
+      .catch(() => {
+        err();
+        done();
+      });
+  } else {
+    conf.customValidator.call(this, err, done, options);
+  }
 }
 
 /*!
diff --git a/test/validations.test.js b/test/validations.test.js
index 670830047..a4b6239a6 100644
--- a/test/validations.test.js
+++ b/test/validations.test.js
@@ -657,6 +657,17 @@ describe('validations', function() {
         done();
       })).should.be.false;
     });
+
+    it.only('should validate using custom async validation using promises', function(done) {
+      User.validateAsync('email', function(options) {
+        return Promise.resolve(true);
+      }, {});
+      var u = new User({email: 'hello'});
+      Boolean(u.isValid(function(valid) {
+        valid.should.be.true;
+        done();
+      })).should.be.false;
+    });
   });
 
   describe('invalid value formatting', function() {