CSV Generate options

All options are optional. All the options from the Node.js Stream Writable are supported and passed as is.

Available options

  • duration (integer)
    Period to run in milliseconds, default to 4 minutes.
  • columns (integer|array|function)
    Define the number of generated fields and the generation method. If columns is an integer, it corresponds to the number of fields. If it is an array, each element correspond to a field. If the field is a function, the function is expected to return a value, if a string, it call the registered function of the same name (eg Generator.int for the value "int"), current values are "ascii", "int" and "bool", more could be added by the user or on demand by opending a pull request. Default to 8 ascii columns.
  • encoding (string)
    If specified, then buffers will be decoded to strings using the specified encoding. The default value is null.
  • max_word_length (integer)
    Maximum number of characters per word. Default to 16.
  • end (integer|date)
    When to stop the generation; could be a numeric value and a date object; default is null.
  • seed (integer)
    Generate idempotent random characters if a number provided. The default value is false which disable the feature.
  • length (integer)
    Number of lines or records to generate. The default value is -1 which is infinite.
  • objectMode (boolean)
    Whether this stream should behave as a stream of objects. Meaning that stream.read(n) returns a single value instead of a Buffer of size n. The default value is false.
  • highWaterMark (integer)
    The maximum number of bytes to store in the internal buffer before ceasing to read from the underlying resource. The default value is 16384 (16kb), or 16 for objectMode streams.

Option objectMode

By the default, the generator will generate a CSV dataset in the form of a string. It is however possible to generate objects but passing the objectMode option native to the writable stream.

In the stream example, each record is returned by the read function in the form of an array.

const generate = require('csv-generate')
const assert = require('assert')
  seed: 1,
  objectMode: true,
  columns: 2,
  length: 1
.on('readable', function(){
  let record
  while(record = this.read()){
    assert.deepEqual(record, [
      'OMH', 'ONKCHhJmjadoA'

In the callback example, the dataset is passed in the callback an array of array.

const generate = require('csv-generate')
  seed: 1,
  objectMode: true,
  columns: 2,
  length: 2
}, function(err, records){
  assert.deepEqual(records, [
    [ 'OMH', 'ONKCHhJmjadoA' ],
    [ 'D', 'GeACHiN' ]