Studio Log Format

🎩 Transform streams to format Studio Log streams

> This module also works in the browser using a [naive stream shim][7] for
> small Browserify bundles.

Usage

``js
const FancyFormat = require('@studio/log-format/fancy');

require('@studio/log')
.pipe(new FancyFormat())
.pipe(process.stdout);
`

Install

`bash
❯ npm i @studio/log-format
`

API

$3

- @studio/log-format/basic: Basic formatting with ISO dates and no colors.
- @studio/log-format/fancy: Colored output with localized dates. This is the
default formatter when using the emojilog CLI.

Some advanced formatting is applied by naming conventions on top level
properties of the data object.

- ts or prefix ts_ formats a timestamp.
- ms or prefix ms_ formats a millisecond value.
- bytes or prefix bytes_ formats a byte value.

These options can be passed to the bundled format transforms:

- ts: false hide timestamps
- topic: false hide topics
- ns: false hide namespaces
- data: false hide data
- stack: style with these stack styles:
- false: hide the error entirely
- message only show the error message
- peek show the message and the first line of the trace (default)
- full show the message and the full trace

The stack option is also used to format the "cause", if present.

$3

- @studio/log-format/console: Console logger, making use of the console.log
default formatting. This format has no options.

Custom Format Transforms

You can also write your own format transforms by implementing a [node transform
streams][5] in writableObjectMode. Here is an example transform
implementation, similar to the [ndjson transform][6] for Studio Log:

`js
const { Transform } = require('stream');

const ndjson = new Transform({
writableObjectMode: true,

transform(entry, enc, callback) {
const str = JSON.stringify(entry);
callback(null, ${str}\n);
}
});
``

Related modules

- 👻 [Studio Log][1] logs ndjson to an output stream
- 🏷 [Studio Log Topics][2] defines the topics used by Studio Log
- 🌈 [Studio Emojilog][3] is a CLI to pretty print the Studio Log ndjson with
emoji
- 📦 [Studio Changes][4] is used to create the changelog for this module.

License

MIT

[1]: https://github.com/javascript-studio/studio-log
[2]: https://github.com/javascript-studio/studio-log-topics
[3]: https://github.com/javascript-studio/studio-emojilog
[4]: https://github.com/javascript-studio/studio-changes
[5]: https://nodejs.org/api/stream.html#stream_implementing_a_transform_stream
[6]: https://github.com/javascript-studio/studio-ndjson
[7]: https://github.com/javascript-studio/studio-browser-stream