经典的“ gulp.src（PATHS.src）”

Question

我正在尝试学习Gulp。我在下面创建了我认为可能会失败的代码，但是它可以正常工作，我想知道为什么吗？ “可写”以作为缓冲区的“ gulp.src（PATHS.src）”的形式接收输入，Node.js文档说它应该接收可读流（“ read.pipe（destination [，options]）”），因此，“ gulp.src（PATHS.src）.pipe（可写）;”应该会失败，但是可以！！！为什么？

var gulp = require('gulp');
var through = require('through2');
var connect = require('gulp-connect');
var fs = require('fs');
var PATHS = {
src : 'src/**/*.ts',
html : 'src/**/*.html',
css : 'src/**/*.css'
};

gulp.task('test', function() {
// This is working !!!
/*
 * fs.createReadStream('ex.txt').pipe(through(function(chunk, enc, callback) 
{
 * console.log("Text is: " + chunk.toString());
 *
 * this.push(chunk)
 *
 * callback() })).pipe(fs.createWriteStream('out.txt')).on('finish',
 * function() { console.log("Kocham Rencie"); })
 */
// But this is not working, why !!!
var writable = through.obj(function(chunk, enc, callback) {
    if (chunk.isStream()) {
        console.log("Chunk is stream ");
        console.log("Path is: " + chunk.path);
    } else if (chunk.isBuffer()) {
        console.log("Path is:"+chunk.path);
        console.log("Chunk is buffer ");
        console.log("***");
        console.log(chunk.contents.toString());
        console.log("***");
    } else {
        console.log("Chunk is something else then stream or buffer");
    }
    this.push(chunk);
    callback(null);

});
gulp.src(PATHS.src).pipe(writable);

}）;