From JSHint's documentation:
ignore
A directive for telling JSHint to ignore a block of code.
// Code here will be linted with JSHint.
/* jshint ignore:start */
// Code here will be linted with ignored by JSHint.
/* jshint ignore:end */
All code in between ignore:start and ignore:end won't be passed to JSHint so you can use any language extension such as Facebook React. Additionally, you can ignore a single line with a trailing comment:
ignoreThis(); // jshint ignore:line