A simple pre-commit hook which runs JSHint on all of the JS files you've changed.

pre-commit

#!/bin/bash
# Runs JSHint on your JS files before a commit
# Place in .git/hooks/pre-commit and chmod +x .git/hooks/pre-commit

if git rev-parse --verify HEAD >/dev/null 2>&1; then
    against=HEAD
else
    # Initial commit: diff against an empty tree object
    against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi

EXIT_CODE=0
for FILE in $(git diff-index --name-only HEAD | sed -n 's/.*js$/&/p'); do
    jshint --verbose --config .jshintrc $FILE

    EXIT_CODE=$((${EXIT_CODE} + $?))
done

if [[ ${EXIT_CODE} -ne 0 ]]; then
    echo ""
    echo "Commit aborted"
fi

exit $((${EXIT_CODE}))