Runs your CoffeeScript source through JSHint to check for errors.

npm install coffee-script -g // See package.json for supported versions (most)
npm install coffee-jshint -g

To check some files:

coffee-jshint file1.coffee file2.coffee ...

JSHint takes a bunch of options that tell it various rules to enforce or relax. Some of these don't make much sense to check for JS generated by the CoffeeScript compiler, so by default these options are turned on:

• undef: warns about use of undeclared variables
• eqnull: suppresses warnings about == null, which CoffeeScript uses in its generated JS
• expr: suppresses warnings about expressions in unexpected positions, which can only occur in generated JS when the CoffeeScript compiler does it on purpose
• shadow: suppresses warnings about variable shadowing, which is fine since CoffeeScript has sane scoping rules and generates safely scoped JS that uses shadowed variables
• sub: suppresses warnings about using bracket object lookup notation (obj['field']) when you could use dot notation (obj.field) since we're grown ups and can make our own decisions about what lookup syntax is best
• multistr: suppresses warnings about multiline strings, since CoffeeScript takes care of them

To turn on more options, you can use the --options or -o flag:

coffee-jshint -o trailing,browser,sub file1.coffee file2.coffee ...

If you really must turn off some of the default options, use the --default-options-off flag (you can always use --options to turn some back on):

coffee-jshint --default-options-off --options undef,eqnull ...

You'll probably get a lot of complaints from Coffee->JSHint about undefined global variables like console, $, or require. Depending on where you're running your code, you might want to allow a few global variables. One easy way to handle this is to use JSHint's built in environment options.

For instance, if you're running your code using Node.js, then you'll want to turn on the node option. It works like any other option:

coffee-jshint -o node ...

If you have some globals that aren't covered by any of environments, well then you should probably check yo'self before you wreck yo'self. But if you really want to turn off warnings for some global variables, Coffee->JSHint supports it using the --globals or -g option. One use case is when using Mocha, a testing library:

coffee-jshint -o node --globals describe,it ...

Coffee->JSHint plays nicely with your favorite Unix utilities. If you want to recursively search all the files in a directory, try piping in the results of a find. Here's an example that also uses grep to filter out files in node_modules/:

find . -type f -path "*.coffee" | grep -v "node_modules/" | xargs coffee-jshint

To use Coffee->JSHint as a git pre-commit hook to check changed files before you commit, put something like this in .git/hooks/pre-commit:

git diff --staged --name-only | xargs coffee-jshint
if [[ $? -ne 0 ]]; then
    echo 'WARNING: You are about to commit files with coffee-jshint warnings'
    exit 1
fi

This will take all the files you plan to commit changes to, run them through coffee-jshint, and exit with status code 1 if there are any warnings (which it will also print out). If there are warnings, the commit will be aborted, but you can always do git commit --no-verify to bypass the hook.