A JSHint task with caching and asynchonous linting.

grunt jshint2

The task I want the grunt-contrib-jshint task to be.

I offered to merge but they didn't seem interested in saving puppies.

Here is an example config showing the default options.

var cfg = {
    jshint2: {
        options: {
            // A path to your jshintrc file if you'd like to use one 
            jshintrc: undefined,
            // jshint options to be passed to jshint.lint. 
            jshint: {
            // A list of predefined variables passed to jshint.lint 
            globals: {
            // What reporter you'd like to use; see Reporters for more info 
            reporter: "default",
            // Do not fail task on jshint errors 
            force: false,
            // Cache successful files; see Caching for more info 
            cache: true,
            // Use the 'async' or 'cluster' processor; see Processors for more info 
            processor: "async",
            // When using the async processor, the max number of files to process at a time. 
            spawnLimit: 5

Caching is done by keeping a computed sha1 hash of the file contents, the jshint options (stringified) and the globals passed to the jshint.lint function.

_getContentsHashfunction(content) {
    var sha1 = crypto.createHash('sha1');
    // The hash should include the file contents 
    // And the jsHintOpts 
    // And the globals 
    return sha1.digest("hex");

After a file is successfully linted an empty file with a name matching it's computed hash is created in a temp directory (using os.tmpDir()). On subsequent jshint calls an existence check of the file determines whether we can skip validating it a second time.

By default, the directory where cached files is stored is dependant on the module version. So updating the module will invalidate any already cached files.

Reporters offer a way to customize the output of the jshint2 task. Since jshint's reporters seem to be in a state of flux at the moment, I've copied their implementations over in order to maintain continuity.

A reporter can be specified in three ways

  1. string (ie. "default" or "xml")
  2. class (ie. require("grunt-jshint2").reporters.xml)
  3. object with the following interface:
// Reporters interface 
var myReporter = {
    startfunction(filestaskOptionsjsHintOptions) { 
        // The task is starting to process files 
    successfunction(filePathwasCached) {
        // A file was successfully linted 
    errorfunction(filePatherrorsdata) {
        // A file had errors 
    finishfunction(files) {   
        // The task is finished processing 

Custom objects will have their options attribute set to the task options. More information available from the lib/reporterResolver.js file.

A processor takes a list of files, some jshint options and globals and runs jshint on each file. The default processor is an asynchronous processor that reads each file and runs jshint. Other processors like the cluster processor can take advantage of multi core machines in order to run jshint on different threads.

At this time it's not possible to write your own processor, but here is the interface that each processor should implement.

function MyProcessor(options) {
    // Options contains; files, jsHintOpts, globals, cache, spawnLimit 
    this.options = options;
_.extend(MyProcessor.prototype, EventEmitter.prototype);
_.extend(MyProcessor.prototype, {
    processFilesfunction() {
        // Begin processing 
        // Must emit the following events: 
        // On lint success 
        this.emit("success", filePath, wasCached);
        // On lint failure 
        this.emit("fail", filePath, problems, data);
        // On error 
        this.emit("error", err);
        // On finish 

Copyright 2013, 2014 Jacob Gable, MIT License.