Enable JSLint and configure its behavior in WebStorm
In the Settings/Preferences dialog Ctrl+Alt+S, go to , and select the Enable checkbox. After that the other controls on the page become available.
In the Tolerate area, specify the types of problems you do not want JSLint to report. By default, the tool reports detected problems of all types. To skip problems of a certain type, select the checkbox next to this type.
Learn more about JSLint options from the JSLint official website.
In the Assume area, specify the targeted environment to check the code for.
Specify the maximum number of problems to report
maxerr, the maximum line length
maxlen, and the predefined global variables by names or through object keys
Select the JSON checkbox in the Validate also area to verify .json files as well.