log-process-errors

Show some ❤️ to Node.js process errors

Description

Node.js prints process errors (`uncaughtException`, `warning`, `unhandledRejection`, `rejectionHandled`) on the console which is very useful. Unfortunately those errors:

- do not show stack traces for `warning` and `rejectionHandled` making them hard to debug. - do not include `multipleResolves` errors (when a promise is resolved/rejected twice). - are inconvenient to log to an external service. - are hard to test. - cannot be conditionally skipped. - are printed each time an error is repeated (except for `warning`). - are not human-friendly.

`log-process-errors` fixes all those issues.

Programming language: JavaScript

License: Apache License 2.0

Tags: Log     Monitoring     Logging     Process     Error-handling     Exception     Debugging    

Latest version: v6.2.0

README

📰 Medium article.

Show some ❤️ to Node.js process errors.

Node.js prints process errors (uncaughtException, warning, unhandledRejection, rejectionHandled) on the console which is very useful. Unfortunately those errors:

• do not show stack traces for warning and rejectionHandled making them hard to debug.
• do not include multipleResolves errors (when a promise is resolved/rejected twice).
• are inconvenient to [log to an external service](docs/API.md#log).
• are hard to [test](docs/API.md#testing).
• cannot be conditionally skipped.
• are printed each time an error is repeated (except for warning).
• are not human-friendly.

log-process-errors fixes all those issues.

Without log-process-errors:

[Screenshot before](docs/before.png)

With log-process-errors:

[Screenshot after](docs/after.png)

Use cases

• Proper logging of process errors in production.
• Debugging of process errors in development.
• Automated testing of process errors.

Demo

You can try this library:

• either directly in your browser.
• or by executing the [examples files](examples/README.md) in a terminal.

Install

Production code (e.g. a server) can install this either as a production or development dependency:

npm install log-process-errors

However, libraries should install this as a development dependency:

npm install -D log-process-errors

This is because logging is modified globally and libraries users might not expect this side-effect. Also, this might lead to conflicts between libraries.

Usage

There are two ways to load this library. The first is to use the node -r CLI flag:

node -r log-process-errors/build/register ...

The second is:

const logProcessErrors = require('log-process-errors')
logProcessErrors(options)

logProcessErrors() should be called as early as possible in the code, before other require/import statements.

Options

options is an optional object with the following properties.

log

Type: function(error, level, originalError)

Customizes how process errors are logged.\ [Full documentation](docs/API.md#log).

level

Type: object\ Default: { warning: 'warn', multipleResolves: 'info', default: 'error' }

Which log level to use.\ [Full documentation](docs/API.md#level).

exitOn

Type: string[]\ Default: ['uncaughtException']

Which process errors should trigger process.exit(1).\ [Full documentation](docs/API.md#exiton).

testing

Type: string\ Value: 'ava', 'mocha', 'jasmine', 'tape' or 'node-tap'\ Default: undefined

When running tests, makes them fail if there are any process errors.\ [Full documentation](docs/API.md#testing).

colors

Type: boolean\ Default: true if the output is a terminal.

Colorizes messages.\ [Full documentation](docs/API.md#colors).

Support

If you found a bug or would like a new feature, don't hesitate to [submit an issue on GitHub](../../issues).

For other questions, feel free to chat with us on Gitter.

Everyone is welcome regardless of personal background. We enforce a [Code of conduct](CODE_OF_CONDUCT.md) in order to promote a positive and inclusive environment.

Contributing

This project was made with ❤️. The simplest way to give back is by starring and sharing it online.

If the documentation is unclear or has a typo, please click on the page's Edit button (pencil icon) and suggest a correction.

If you would like to help us fix a bug or add a new feature, please check our [guidelines](CONTRIBUTING.md). Pull requests are welcome!

Thanks go to our wonderful contributors:

<!-- ALL-CONTRIBUTORS-LIST:START --> <!-- prettier-ignore-start --> <!-- markdownlint-disable --> ehmicky💻 🎨 🤔 📖 Steven Vachon💬 Hongarc📖 💻 Andy Brenneke🐛

<!-- markdownlint-enable --> <!-- prettier-ignore-end -->

<!-- ALL-CONTRIBUTORS-LIST:END -->