writeJSON is not writing valid json

[apetta]

Have you tried latest version of polars?

• [yes]

What version of polars are you using?

0.14.0

What operating system are you using polars on?

MacOS

What node version are you using

18.18.2

Describe your bug.

A dataframe exported as JSON is missing the top-level array & commas. It just exports something like:

{"id":"group:1","key":"a"}
{"id":"group:2","key":"b"}
{"id":"group:3","key":"c"}
{"id":"group:4","key":"d"}

What are the steps to reproduce the behavior?

Make a dataframe and export it to json

Example

import pl from "nodejs-polars";

// Create a simple dataset on which we can reproduce the bug.
pl.DataFrame({
  foo: [1, 1, 2],
  bar: [1n, 2n, 3n],
}).writeJSON("test.json");

What is the actual behavior?

Show the query you ran and the actual output.

If the output is large, put it in a gist: https://gist.github.com/

If the output is small, put it in code fences:

{"foo":1.0,"bar":1}
{"foo":1.0,"bar":2}
{"foo":2.0,"bar":3}

What is the expected behavior?

[
  { "foo": 1.0, "bar": 1 },
  { "foo": 1.0, "bar": 2 },
  { "foo": 2.0, "bar": 3 }
]

[universalmind303]

@apetta this is a valid json format called ndjson/json-lines.

It's generally much more performant than the standard json format.

We also support standard json.

https://pola-rs.github.io/nodejs-polars/interfaces/pl.DataFrame-1.html#writeJSON

[apetta]

@universalmind303 my bad for not reading the docs properly, thank you!