Combining a stream with a entire dataset

It leverages the stream transform API but input doesn't have to be an readable stream and output doesn't have to be a writable stream. Input may be a string passed as first argument. Output may be obtained in the callback passed as last argument.

Uses it for convenience in case you are already interacting with a readable stream or a writable stream. It is not scalable because it implies that you either have all your records in memory and wish to pipe the generated CSV into a stream writer or that you have a stream reader generated records and wish to obtain a string representing the full CSV text.

The signature of the output stream example is const stream = stringify(input, [options]). It takes an input string and an options object as arguments and return a readable stream.

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

const data = [];
stringify([
  ["1", "2", "3", "4"],
  ["a", "b", "c", "d"],
])
  // Use the readable stream api
  .on("readable", function () {
    let row;
    while ((row = this.read()) !== null) {
      data.push(row);
    }
  })
  // When we are done, test that the parsed records matched what expected
  .on("end", function () {
    assert.deepStrictEqual(data.join(""), "1,2,3,4\na,b,c,d\n");
  });

./packages/csv-stringify/samples/mixed.output_stream.js

Inversely, the signature of the input stream example is const stream = stringify([options], callback). It takes an options object and a callback function as arguments and return a writable stream.

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

// Create the parser
const stringifier = stringify(
  {
    delimiter: ":",
  },
  function (err, data) {
    assert.deepStrictEqual(
      data,
      "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/mixed.output_stream.js