fix: Fix using is/in in $nin subquery (#176)

helpers/conditional.js

@@ -156,8 +156,8 @@ conditionals.add('$in', { cascade: false }, function(column, set, values, collec
  */
 conditionals.add('$nin', { cascade: false }, function(column, set, values, collection, original){
   return conditionals.get('$in').fn(column, set, values, collection, original)
-    .replace(/in/g, 'not in')
-    .replace(/is/g, 'is not');
+    .replace(new RegExp(column + ' in', 'g'), column + ' not in')
+    .replace(new RegExp(column + ' is', 'g'), column + ' is not');
 });
 
 /**

test/conditions.js

@@ -583,6 +583,32 @@ describe('Conditions', function(){
     assert.deepEqual(query.values , []);
   });
 
+  it ('$nin with subquery', function(){
+    var query = builder.sql({
+      type: 'select'
+    , table: 'users'
+    , where: {
+        id: {
+          $nin: {
+            type: 'select'
+          , table: 'sub'
+          , columns: ['user_id']
+          , where: {
+              value: {
+                $null: false
+              }
+            }
+          }
+        }
+      }
+    });
+
+    assert.equal(
+      query.toString()
+    , 'select "users".* from "users" where "users"."id" not in (select "sub"."user_id" from "sub" where "sub"."value" is not null)'
+    );
+  });
+
   it ('should allow an arbitrary amount of conditions', function(){
     var query = builder.sql({
       type: 'select'