jsonlines-web

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Web stream based jsonlines decoder/encoder

- ✅Deno
- ✅browser
- ✅Node.js

This library supports JSON in the following formats:

- Line-delimited JSON (JSONLinesParseStream)
- NDJSON
- JSON lines
- Record separator-delimited JSON (JSONLinesParseStream)
- Concatenated JSON (ConcatenatedJSONParseStream)

See wikipedia for the
specifications of each JSON.

install or import

$3

https://deno.land/x/jsonlines/
https://doc.deno.land/https://deno.land/x/jsonlines/mod.ts

``ts
import {
ConcatenatedJSONParseStream,
ConcatenatedJSONStringifyStream,
JSONLinesParseStream,
JSONLinesStringifyStream,
} from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";
`

$3

`ts
import {
ConcatenatedJSONParseStream,
ConcatenatedJSONStringifyStream,
JSONLinesParseStream,
JSONLinesStringifyStream,
} from "https://deno.land/x/jsonlines@v1.2.1/js/mod.js";
`

$3

https://www.npmjs.com/package/jsonlines-web

`shell
npm install jsonlines-web
`

`ts, ignore
import {
ConcatenatedJSONParseStream,
ConcatenatedJSONStringifyStream,
JSONLinesParseStream,
JSONLinesStringifyStream,
} from "jsonlines-web";
// if you need
// import { TextDecoderStream, TextEncoderStream } from "node:stream/web";
// import { fetch } from "undici";
`

Usage

A working example can be found at ./testdata/test.ts.

$3

./json-lines.jsonl

`json
{"some":"thing"}
{"foo":17,"bar":false,"quux":true}
{"may":{"include":"nested","objects":["and","arrays"]}}
`

`ts
import { JSONLinesParseStream } from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";

const { body } = await fetch(
"https://deno.land/x/jsonlines@v1.2.1/testdata/json-lines.jsonl",
);

const readable = body!
.pipeThrough(new TextDecoderStream())
.pipeThrough(new JSONLinesParseStream());

for await (const data of readable) {
console.log(data);
}
`

$3

./json-seq.json-seq

`json
{"some":"thing\n"}
{
"may": {
"include": "nested",
"objects": [
"and",
"arrays"
]
}
}
`

`ts
import { JSONLinesParseStream } from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";

const { body } = await fetch(
"https://deno.land/x/jsonlines@v1.2.1/testdata/json-seq.json-seq",
);

const recordSeparator = "\x1E";
const readable = body!
.pipeThrough(new TextDecoderStream())
.pipeThrough(new JSONLinesParseStream({ separator: recordSeparator }));

for await (const data of readable) {
console.log(data);
}
`

$3

./concat-json.concat-json

`json
{"foo":"bar"}{"qux":"corge"}{"baz":{"waldo":"thud"}}
`

`ts
import { ConcatenatedJSONParseStream } from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";

const { body } = await fetch(
"https://deno.land/x/jsonlines@v1.2.1/testdata/concat-json.concat-json",
);

const readable = body!
.pipeThrough(new TextDecoderStream())
.pipeThrough(new ConcatenatedJSONParseStream());

for await (const data of readable) {
console.log(data);
}
`

$3

`ts
import { readableStreamFromIterable } from "https://deno.land/std@0.138.0/streams/mod.ts";
import { JSONLinesStringifyStream } from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";

const file = await Deno.open(new URL("./tmp.concat-json", import.meta.url), {
create: true,
write: true,
});

readableStreamFromIterable([{ foo: "bar" }, { baz: 100 }])
.pipeThrough(new JSONLinesStringifyStream())
.pipeThrough(new TextEncoderStream())
.pipeTo(file.writable)
.then(() => console.log("write success"));
`

$3

`ts
import { readableStreamFromIterable } from "https://deno.land/std@0.138.0/streams/mod.ts";
import { JSONLinesStringifyStream } from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";

const recordSeparator = "\x1E";
const file = await Deno.open(new URL("./tmp.concat-json", import.meta.url), {
create: true,
write: true,
});

readableStreamFromIterable([{ foo: "bar" }, { baz: 100 }])
.pipeThrough(new JSONLinesStringifyStream({ separator: recordSeparator }))
.pipeThrough(new TextEncoderStream())
.pipeTo(file.writable)
.then(() => console.log("write success"));
`

$3

`ts
import { readableStreamFromIterable } from "https://deno.land/std@0.138.0/streams/mod.ts";
import { ConcatenatedJSONStringifyStream } from "https://deno.land/x/jsonlines@v1.2.1/mod.ts";

const file = await Deno.open(new URL("./tmp.concat-json", import.meta.url), {
create: true,
write: true,
});

readableStreamFromIterable([{ foo: "bar" }, { baz: 100 }])
.pipeThrough(new ConcatenatedJSONStringifyStream())
.pipeThrough(new TextEncoderStream())
.pipeTo(file.writable)
.then(() => console.log("write success"));
`

note

This library contains
[ReadableStream.prototype[Symbol.asyncIterator]](https://github.com/whatwg/streams/issues/778)
polyfills. Importing this library will automatically enable
ReadableStream.prototype[Symbol.asyncIterator].

develop

need to manually deno task transpile` before release.