index.js

/*
  MIT License http://www.opensource.org/licenses/mit-license.php
  Author William Buchwalter
  based on jshint-loader by Tobias Koppers
*/
var Linter = require("tslint");
var tslintConfig = require("tslint/lib/configuration");
var stripJsonComments = require("strip-json-comments");
var fs = require("fs");
var path = require("path");
var typescript = require("typescript");
var mkdirp = require("mkdirp");
var rimraf = require("rimraf");
var objectAssign = require("object-assign");


function loadRelativeConfig() {
  var options = {
     formatter: "custom",
     formattersDirectory: __dirname + '/formatters/',
     configuration: tslintConfig.findConfiguration(null, this.resourcePath)
  };

  return options;
}

function lint(input, options) {
  //Override options in tslint.json by those passed to the compiler
  if(this.options.tslint) {    
    objectAssign(options, this.options.tslint);
  }

  var bailEnabled = (this.options.bail === true);

  //Override options in tslint.json by those passed to the loader as a query string
  objectAssign(options, this.query || {});   
  
  var linter = new Linter(this.resourcePath, input, options);
  var result = linter.lint();
  var emitter = options.emitErrors ? this.emitError : this.emitWarning;

  report(result, emitter, options.failOnHint, options.fileOutput, this.resourcePath,  bailEnabled);
}

function report(result, emitter, failOnHint, fileOutputOpts, filename, bailEnabled) {
  if(result.failureCount === 0) return;    
  emitter(result.output);

  if(fileOutputOpts && fileOutputOpts.dir) {
    writeToFile(fileOutputOpts, result);
  }

  if(failOnHint) {
    var messages = "";
    if (bailEnabled){
      messages = "\n\n" + filename + "\n" + result.output;
    }
    throw new Error("Compilation failed due to tslint errors." +  messages);
  }
}

var cleaned = false;

function writeToFile(fileOutputOpts, result) {
  if(fileOutputOpts.clean === true && cleaned === false) {
    rimraf.sync(fileOutputOpts.dir);
    cleaned = true;
  }

  if(result.failures.length) {
    mkdirp.sync(fileOutputOpts.dir);

    var relativePath = path.relative("./", result.failures[0].fileName);

    var targetPath = path.join(fileOutputOpts.dir, path.dirname(relativePath));
    mkdirp.sync(targetPath);

    var extension = fileOutputOpts.ext || "txt";

    var targetFilePath = path.join(fileOutputOpts.dir, relativePath + "." + extension);

    var contents = result.output;

    if(fileOutputOpts.header) {
      contents = fileOutputOpts.header + contents;
    }

    if(fileOutputOpts.footer) {
      contents = contents + fileOutputOpts.footer;
    }

    fs.writeFileSync(targetFilePath, contents);
  }
}

module.exports = function(input, map) {
  this.cacheable && this.cacheable();
  var callback = this.async();

  var config = loadRelativeConfig.call(this);
  lint.call(this, input, config);  
  callback(null, input, map);
};