Change behaviour for "$notIn empty array" (fixes #4859) (#4860)

* Change behaviour for "$notIn empty array"

* Make sure value in escape method is a string

lib/dialects/abstract/query-generator.js

@@ -2191,7 +2191,11 @@ var QueryGenerator = {
           return self.escape(item);
         }).join(', ')+')';
       } else {
+        if (value.$in) {
           value = '(NULL)';
+        } else {
+          return '';
+        }
       }
     } else if (value && (value.$any || value.$all)) {
       comparator = value.$any ? '= ANY' : '= ALL';

lib/sql-string.js

@@ -55,6 +55,10 @@ SqlString.escape = function(val, timeZone, dialect, format) {
     return val.map(escape);
   }
 
+  if (!val.replace) {
+    throw new Error('Invalid value ' + val);
+  }
+
   if (dialect === 'postgres' || dialect === 'sqlite' || dialect === 'mssql') {
     // http://www.postgresql.org/docs/8.2/static/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS
     // http://stackoverflow.com/q/603572/130598

test/unit/sql/where.test.js

@@ -154,7 +154,7 @@ suite(Support.getTestDialectTeaser('SQL'), function() {
       testsql('equipment', {
         $notIn: []
       }, {
-        default: '[equipment] NOT IN (NULL)'
+        default: ''
       });
 
       testsql('equipment', {