index.js

var tsd     = require('./lib/tsd');
var through = require('through2');
var gutil   = require('gulp-util');
var path    = require('path');
var debug   = require('debug')('gulp-tsd');

module.exports = function (options, callback) {
    'use strict';

    var settings = [];
    if (options) {
        settings.push(options);
    }

    var logger = {
        'log': function () {
            var args = Array.prototype.slice.call(arguments),
                printfString = Array.apply(null, Array(args.length)).map(function(){return '%o';}).join(' ');

            args.unshift(printfString);
            debug.apply(null, args);
        }
    };

    var finishedWorkers = 0;
    var promised = function (context, promise, callback) {
        promise.done(function () {
            if (settings.length === ++finishedWorkers) {
                logger.log('finish');
                return callback();
            }
        }, function (err) {
            if (settings.length === ++finishedWorkers) {
                context.emit('error', new gutil.PluginError('gulp-tsd', 'Failed command execution: ' + err.stack));
                return callback();
            }
        });
    };

    function transform(file, encode, callback) {
        /*jshint validthis:true */
        if (file.isNull()) {
            this.push(file);
            return callback();
        }

        if (file.isStream()) {
            this.emit('error', new gutil.PluginError('gulp-tsd', 'Streaming not supported'));
            return callback();
        }

        settings.push(require(path.resolve(file.path)));

        callback();
    }

    function flush(callback) {
        /*jshint validthis:true */
        var self = this;
        settings.forEach(function (setting) {
            var command = setting.command;
            var tsdCommand = tsd.getRunner(logger).commands[command];
            if (typeof tsdCommand === 'undefined') {
                self.emit(
                    'error',
                    new gutil.PluginError('gulp-tsd', '"' + command + '"' + ' command is not supported')
                );
                return callback();
            }

            return promised(self, tsdCommand(setting), callback);
        });
    }

    if (callback) {
        flush(callback);
    }

    return through.obj(transform, flush);
};