a-miyashita/gulp-custom-filter

'use strict';

var assertIsString = require('./assertions').isString;
var assertIsStringOrArray = require('./assertions').isStringOrArray;
var colors = require('ansi-colors');
var fs = require('fs');
var ig = require('ignore');
var log = require('fancy-log');
var minimatch = require('minimatch');
var path = require('path');

function glob(pattern, options) {
    assertIsStringOrArray(pattern, 'glob', 'pattern');
    return function(file, encode) {
        return minimatch(file.relative, pattern, options);
    };
}

function ignore(filename) {
    assertIsString(filename, 'ignore', 'filename');
    var ignoreFilter = null;
    var error = null;
    var queue = [];

    fs.readFile(filename, function(err, data) {
        if (err) {
            log(colors.red('gulp-custom-filter.ignore: ' + err));
            error = err;
        } else {
            ignoreFilter = ig().addPattern(
                data.toString('utf-8')
                    .replace(/\r/g, '\n').trim().split('\n')
                    .filter(function (str) {
                        return str.length > 0;
                    })
                    .map(normalize)
            ).createFilter();
        }
        queue.forEach(function(entry) {
            if (error) {
                entry.callback(error);
            } else {
                entry.callback(null, ignoreFilter(normalize(entry.filename)));
            }
        });
    });

    return function(file, encode, callback) {
        if (error) {
            callback(error);
        } else if (ignoreFilter !== null) {
            callback(null, ignoreFilter(normalize(file.relative)));
        } else {
            queue.push({
                callback: callback,
                filename: file.relative
            });
        }
    };
}

function normalize(filename) {
    return path.normalize(filename).replace(/\\/g, '/');
}

module.exports = {
    glob: glob,
    ignore: ignore
};