/**
 * @fileOverview There is a compatibility problem between eslint and arcanist.
 *               ESLint returns a non-zero code on exit if there are any lint errors
 *               in the file.  But `arc` regex liniters expect to only get an
 *               non-zero exit code on true errors (e.g. eslint config errors).
 *
 *              So we use this file and the ESLint API to build a version that
 *              only returns non-zero on actual errors (which will be unhandled
 *              exceptions, so we don't actually need to do anything to achieve)
 */
const CLIEngine = require('eslint').CLIEngine;

const cli = new CLIEngine();

/**
 * Get the file to lint from the command line.  The command line is always
 * argv[0] - node exe
 * argv[1] - this script
 * argv[2] - the file passed on the command line
 */
if (process.argv.length !== 3) {
    throw new Error('Must pass exactly 1 file on the command line');
}

const filename = process.argv[2];

// Lint the file passed in
const report = cli.executeOnFiles([filename]);

// Get the compact formatter
const formatter = cli.getFormatter('compact');

// Output to stdout so it can be picked up by the arcanist regex
process.stdout.write(formatter(report.results));

// Allow the program to exit normally, which will return code 0