vv-filestream

For NodeJS, custom WriteStream, based on standard fs.WriteStream.

Features

1. Parallel writing multiple files (with once callback after the end of recording all files)
2. Ability to write JSON through the stream (see example)

License

MIT

Install

npm i vv-filestream

Example

Writing two files. Each file is written in two chunks. First file has bad name, second file has good name.

code

const path = require('path')
const fs = require('fs')
const fileNameBad = 'a:/bad.json'
const fileNameGood = path.join(__dirname, 'good.json')
const data1 = [{aaaa: 1},{aaaa: 2},{aaaa: 3}]
const data2 = [{aaaa: 1, bbbb: 1},{aaaa: 2, bbbb: 2},{aaaa: 3, bbbb: 3},{aaaa: 4, bbbb: 4},{aaaa: 5, bbbb: 5}]
const vvfs = require('vv-filestream').Create({prefix: '[\n', suffix: '{}\n]'})
vvfs.onClose(result => {
    result.forEach(f => {
        console.log(`file   ${f.fullFileName}`)
        if (f.error) {
            console.log(`ERROR   ${f.error.message}`)
        } else {
            console.log('DATA')
            console.log(JSON.parse(fs.readFileSync(f.fullFileName, 'utf8')))
        }
    })
})
vvfs.write({fullFileName: fileNameBad, data: data1.slice(0, 2)})
vvfs.write({fullFileName: fileNameGood, data: data2.slice(0, 2)})
vvfs.write({fullFileName: fileNameBad, data: data1.slice(2, 5)})
vvfs.write({fullFileName: fileNameGood, data: data2.slice(2, 5)})
vvfs.close()

note for result

1. result in vvfs.onClose - array:

[
    {fullFileName: 'a:/bad.json', error: Error: ENOENT: no such file or directory, open 'a:\\bad.json'}
    {fullFileName: ' ...  good.json', error: undefined}
]

2. file good.json has content (last empty object used to escape the comma after the previous line):

[
{"aaaa":1,"bbbb":2},
{"aaaa":2,"bbbb":2},
{"aaaa":3,"bbbb":3},
{"aaaa":4,"bbbb":4},
{"aaaa":5,"bbbb":5},
{}
]