fix(mongoose): add global usePushEach option for easier Mongoose 4.x + MongoDB 3.6

Fix #6858

Author: vkarpov15

lib/model.js

@@ -432,7 +432,14 @@ function handleAtomics(self, where, delta, data, value) {
     value.$__getAtomics().forEach(function(atomic) {
       var op = atomic[0];
       var val = atomic[1];
-      if (self.schema.options.usePushEach && op === '$pushAll') {
+      var usePushEach = false;
+      if ('usePushEach' in get(self, 'constructor.base.options', {})) {
+        usePushEach = self.constructor.base.get('usePushEach');
+      }
+      if ('usePushEach' in self.schema.options) {
+        usePushEach = self.schema.options.usePushEach;
+      }
+      if (usePushEach && op === '$pushAll') {
         op = '$push';
         val = { $each: val };
       }

test/common.js

@@ -100,6 +100,23 @@ module.exports = function(options) {
   return conn;
 };
 
+/*!
+ * ignore
+ */
+
+before(function(done) {
+  module.exports.mongodVersion(function(err, version) {
+    if (err) {
+      return done(err);
+    }
+    var mongo36 = version[0] > 3 || (version[0] === 3 && version[1] >= 6);
+    if (mongo36) {
+      mongoose.set('usePushEach', true);
+    }
+    done();
+  });
+});
+
 /*!
  * testing uri
  */