JSHint (version 1.0.0 and above) will throw the "Wrapping non-IIFE function literals in parens is unnecessary" error when it encounters a function expression wrapped in parentheses with no following invoking parentheses, but only if the immed option is set to true. In the following example we assign a function expression to a variable x:
This is the equivalent of the JSLint and older JSHint "Do not wrap function literals in parens unless they are to be immediately invoked" warning. More detail can be found on the page for that message.
If you have not come across the acronym "IIFE" before, you may be interested in Ben Alman's article on the subject, in which he coins the term to stand for "Immediately Invoked Function Expression".
In JSHint 1.0.0 and above you have the ability to ignore any warning with a special option syntax. The identifier of this warning is W068. This means you can tell JSHint to not issue this warning with the /*jshint -W068 */ directive.