Node.js Stream API

The main module of the package implements the native Node.js transform stream which is both readable and writable.

This is the recommended approach if you need a maximum of power. It ensures scalability by treating your data as a stream from the source to the destination.

The signature is const stream = stringify([options]).

The stream example write 2 records and register multiple events to read the generated CSV output and get notified when the serialisation is finished.

import { stringify } from "csv-stringify";
import assert from "node:assert";

const data = [];
// Initialize the stringifier
const stringifier = stringify({
  delimiter: ":",
});
// Use the readable stream api to consume CSV data
stringifier.on("readable", function () {
  let row;
  while ((row = stringifier.read()) !== null) {
    data.push(row);
  }
});
// Catch any error
stringifier.on("error", function (err) {
  console.error(err.message);
});
// When finished, validate the CSV output with the expected value
stringifier.on("finish", function () {
  assert.equal(
    data.join(""),
    "root:x:0:0:root:/root:/bin/bash\n" +
      "someone:x:1022:1022::/home/someone:/bin/bash\n",
  );
});
// Write records to the stream
stringifier.write(["root", "x", "0", "0", "root", "/root", "/bin/bash"]);
stringifier.write([
  "someone",
  "x",
  "1022",
  "1022",
  "",
  "/home/someone",
  "/bin/bash",
]);
// Close the writable stream
stringifier.end();

./packages/csv-stringify/samples/api.stream.js

After cloning the project repository, run this example with the command node samples/api.stream.js.