Text and data formats

Each package has a DecoderStream that gives the same output however the input is split into chunks. You can pipe a fetch body into it directly.

• csv decodes and encodes CSV, with or without a header row.
• jsonl decodes and encodes JSON Lines.
• json-stream selects values from a JSON document too large to parse at once, by JSONPath.
• lines splits text into lines for formats with no package of their own.
• sse reads and writes server-sent events.

Convert a CSV export to JSON Lines

import * as Csv from '@portable/csv';
import * as Jsonl from '@portable/jsonl';
 
export default {
  async fetch() {
    const response = await fetch('https://example.com/users.csv');
    const body = response
      .body!.pipeThrough(new Csv.DecoderStream({ header: true }))
      .pipeThrough(new Jsonl.EncoderStream());
    return new Response(body, {
      headers: { 'content-type': 'application/jsonl' },
    });
  },
};

The Worker converts each row as it arrives, so its memory use doesn't grow with the size of the file.