nedb/test/byline.test.js

/* eslint-env mocha */
// Copyright (C) 2013-2015 John Hewson
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.

const chai = require('chai')
const fs = require('fs')
const path = require('path')
const byline = require('../lib/byline')

const { assert } = chai

const regEx = /\r\n|[\n\v\f\r\x85\u2028\u2029]/g
const localPath = file => path.join(__dirname, 'byline', file)

describe('byline', function () {
  it('should pipe a small file', function (done) {
    const input = fs.createReadStream(localPath('empty.txt'))
    const lineStream = byline(input) // convinience API
    const output = fs.createWriteStream(localPath('test.txt'))
    lineStream.pipe(output)
    output.on('close', function () {
      const out = fs.readFileSync(localPath('test.txt'), 'utf8')
      const in_ = fs.readFileSync(localPath('empty.txt'), 'utf8').replace(/\n/g, '')
      assert.equal(in_, out)
      fs.unlinkSync(localPath('test.txt'))
      done()
    })
  })

  it('should work with streams2 API', function (done) {
    let stream = fs.createReadStream(localPath('empty.txt'))
    stream = byline(stream)

    stream.on('readable', function () {
      while (stream.read() !== null) {
        // eslint-ignore-line no-empty
      }
    })

    stream.on('end', function () {
      done()
    })
  })

  it('should ignore empty lines by default', function (done) {
    const input = fs.createReadStream(localPath('empty.txt'))
    const lineStream = byline(input)
    lineStream.setEncoding('utf8')

    const lines1 = []
    lineStream.on('data', function (line) {
      lines1.push(line)
    })

    lineStream.on('end', function () {
      let lines2 = fs.readFileSync(localPath('empty.txt'), 'utf8').split(regEx)
      lines2 = lines2.filter(function (line) {
        return line.length > 0
      })
      assert.deepEqual(lines2, lines1)
      done()
    })
  })

  it('should keep empty lines when keepEmptyLines is true', function (done) {
    const input = fs.createReadStream(localPath('empty.txt'))
    const lineStream = byline(input, { keepEmptyLines: true })
    lineStream.setEncoding('utf8')

    const lines = []
    lineStream.on('data', function (line) {
      lines.push(line)
    })

    lineStream.on('end', function () {
      assert.deepEqual(['', '', '', '', '', 'Line 6'], lines)
      done()
    })
  })

  it('should not split a CRLF which spans two chunks', function (done) {
    const input = fs.createReadStream(localPath('CRLF.txt'))
    const lineStream = byline(input, { keepEmptyLines: true })
    lineStream.setEncoding('utf8')

    const lines = []
    lineStream.on('data', function (line) {
      lines.push(line)
    })

    lineStream.on('end', function () {
      assert.equal(2, lines.length)
      done()
    })
  })

  it('should read a large file', function (done) {
    readFile(localPath('rfc.txt'), done)
  })

  it('should read a huge file', function (done) {
    // Readable highWaterMark is 16384, so we test a file with more lines than this
    readFile(localPath('rfc_huge.txt'), done)
  })

  function readFile (filename, done) {
    const input = fs.createReadStream(filename)
    const lineStream = byline(input)
    lineStream.setEncoding('utf8')

    let lines2 = fs.readFileSync(filename, 'utf8').split(regEx)
    lines2 = lines2.filter(function (line) {
      return line.length > 0
    })

    const lines1 = []
    let i = 0
    lineStream.on('data', function (line) {
      lines1.push(line)
      if (line !== lines2[i]) {
        console.log('EXPECTED:', lines2[i])
        console.log('     GOT:', line)
        assert.fail(null, null, 'difference at line ' + (i + 1))
      }
      i++
    })

    lineStream.on('end', function () {
      assert.equal(lines2.length, lines1.length)
      assert.deepEqual(lines2, lines1)
      done()
    })
  }

  it('should handle encodings like fs', function (done) {
    areStreamsEqualTypes(undefined, function () {
      areStreamsEqualTypes({ encoding: 'utf8' }, function () {
        done()
      })
    })
  })

  it('should pause() and resume() with a huge file', function (done) {
    const input = fs.createReadStream(localPath('rfc_huge.txt'))
    const lineStream = byline(input)
    lineStream.setEncoding('utf8')

    let lines2 = fs.readFileSync(localPath('rfc_huge.txt'), 'utf8').split(regEx)
    lines2 = lines2.filter(function (line) {
      return line.length > 0
    })

    const lines1 = []
    let i = 0
    lineStream.on('data', function (line) {
      lines1.push(line)
      if (line !== lines2[i]) {
        console.log('EXPECTED:', lines2[i])
        console.log('     GOT:', line)
        assert.fail(null, null, 'difference at line ' + (i + 1))
      }
      i++

      // pause/resume
      lineStream.pause()
      setImmediate(function () {
        lineStream.resume()
      })
    })

    lineStream.on('end', function () {
      assert.equal(lines2.length, lines1.length)
      assert.deepEqual(lines2, lines1)
      done()
    })
  })

  function areStreamsEqualTypes (options, callback) {
    const fsStream = fs.createReadStream(localPath('empty.txt'), options)
    const lineStream = byline(fs.createReadStream(localPath('empty.txt'), options))
    fsStream.on('data', function (data1) {
      lineStream.on('data', function (data2) {
        assert.equal(Buffer.isBuffer(data1), Buffer.isBuffer(data2))
      })
      lineStream.on('end', function () {
        callback()
      })
    })
  }
})