node web scraper - 【とらのあなWebSite】とらの瞬間風速

package.json

{
  "dependencies": {
    "destroy": "^1.0.3",
    "JSONStream": "^1.0.4",
    "hyperquest": "^1.2.0",
    "iconv-lite": "^0.4.11",
    "through2": "^2.0.0",
    "trumpet": "^1.7.1"
  }
}

web-scraper-toranoana.js

'use strict'
var hyperquest = require('hyperquest')
var iconv      = require('iconv-lite')
var trumpet    = require('trumpet')
var through    = require('through2')
var JSONStream = require('JSONStream')
var destroy    = require('destroy')

var uri      = 'http://www.toranoana.jp/mailorder/watch/wi_gen_all.html'
var selector = '.Main table.table_index_Frame_2 tr td table.whole_w_left tr td table.watch tr td.watch1 a'

var rs = through.obj()
var tr = trumpet()

tr.selectAll(selector, function (a) {
    var buf = []
    a.createReadStream()
        .pipe(iconv.decodeStream('cp932'))
        .pipe(through.obj(function (c, enc, done) {
            buf.push(c)
            done()
        }, function (done) {
            var data
            ;(Buffer.isBuffer(buf[0])) ? (data = String(Buffer.concat(buf)))
                                       : (data = buf.join(''))
            a.getAttribute('href', function (href) {
                rs.write({
                    href: href
                  , text: data
                })
                done()
            })
        }))
})

tr.once('end', rs.end.bind(rs))

hyperquest(uri).once('error', onError).once('response', onResponse)
    .pipe(tr)

rs
    .pipe(JSONStream.stringify())
    .pipe(process.stdout)


function onError (err) {
    console.error(err)
}

function onResponse (res) {
    if (res.statusCode !== 200) {
        destroy(res)
        return onError(new Error(res.statusCode + ': ' + uri))
    }
}