From ce7fb11815fcadc8412bfdcaa2cd31c8647bcdad Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 26 Apr 2018 17:56:20 -0400
Subject: [PATCH] feat(error): add version number to VersionError

backport to 4.x of dd2483d1167f0878ca075835858d5708dfc307ac
---
 lib/error/version.js    | 5 +++--
 lib/model.js            | 7 ++++---
 test/versioning.test.js | 1 +
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/error/version.js b/lib/error/version.js
index 719c07f1254..33d1bd88e66 100644
--- a/lib/error/version.js
+++ b/lib/error/version.js
@@ -13,10 +13,11 @@ var MongooseError = require('./');
  * @api private
  */
 
-function VersionError(doc) {
+function VersionError(doc, currentVersion) {
   MongooseError.call(this, 'No matching document found for id "' + doc._id +
-    '"');
+    '" version ' + currentVersion);
   this.name = 'VersionError';
+  this.version = currentVersion;
 }
 
 /*!
diff --git a/lib/model.js b/lib/model.js
index 1d1defedd7b..8b85100599f 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -258,16 +258,17 @@ Model.prototype.$__save = function(options, callback) {
       var doIncrement = VERSION_INC === (VERSION_INC & _this.$__.version);
       _this.$__.version = undefined;
 
+      var key = _this.schema.options.versionKey;
+      var version = _this.getValue(key) || 0;
+
       if (numAffected <= 0) {
         // the update failed. pass an error back
-        var err = new VersionError(_this);
+        var err = new VersionError(_this, version);
         return callback(err);
       }
 
       // increment version if was successful
       if (doIncrement) {
-        var key = _this.schema.options.versionKey;
-        var version = _this.getValue(key) | 0;
         _this.setValue(key, version + 1);
       }
     }
diff --git a/test/versioning.test.js b/test/versioning.test.js
index db2e9854dc3..4e6856c8b08 100644
--- a/test/versioning.test.js
+++ b/test/versioning.test.js
@@ -265,6 +265,7 @@ describe('versioning', function() {
     function test4(err, a, b) {
       assert.ok(/No matching document/.test(err), err);
       assert.equal(a._doc.__v, 5);
+      assert.equal(err.version, b._doc.__v - 1);
       a.set('arr.0.0', 'updated');
       var d = a.$__delta();
       assert.equal(a._doc.__v, d[0].__v, 'version should be added to where clause');