Change Eclipse settings to ignore errors on a specific file

It looks like eclipse has changed a bit,
but the following method which worked for me seems very close to the old one.

The solution consists of 2 steps:

1. First you have to update Eclipse’s preferences (Window > Preferences):

   

   Make sure that you check both Manual & Build next to the Validator you need
   (in my case – a javascript one).

2. Last you should change your project’s Validators:

   

   Click on Client-side JavaScript Settings (or any other validator you need):

   

   The explanation is clear but basically what you should do is as follows:

   Click on Add Exclude Group..., select it and then click on Add rule....
   Then pick Folder or file name (note that there are other options), and specify your file/folder.

You should be able to verify that its working by deleting the existing errors/warnings,
and then left-click your project and select the Validate option.

This setting can be committed into source control as well.