https://github.com/yakkomajuri/structlog

A lightweight structured logging tool for Node.js without any dependencies.
https://github.com/yakkomajuri/structlog

javascript javascript-library log logger logging nodejs npm npm-package structured-logging

Last synced: about 2 months ago
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A lightweight structured logging tool for Node.js without any dependencies.

• Host: GitHub
• URL: https://github.com/yakkomajuri/structlog
• Owner: yakkomajuri
• License: mit
• Created: 2022-03-09T10:25:12.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2022-03-15T16:25:57.000Z (almost 3 years ago)
• Last Synced: 2024-10-13T11:45:55.006Z (3 months ago)
• Topics: javascript, javascript-library, log, logger, logging, nodejs, npm, npm-package, structured-logging
• Language: TypeScript
• Homepage: https://www.npmjs.com/package/structlog
• Size: 389 KB
• Stars: 5
• Watchers: 3
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# structlog

A lightweight structured logging tool for Node.js without any dependencies.

## Example

By default this tool will generate logs like the following:

```

2022-03-09T19:57:48.962Z [error] i'm an error [/structlog/foo.js:5] thread=MAIN logId=017f705b-4200-0002-1101-720541fa117c 

2022-03-09T19:57:48.963Z [warn] i'm a warning [/structlog/foo.js:6] thread=MAIN logId=017f705b-4200-0000-e4a6-f1df2ca4f248

```

However, you can configure both the log and timestamp formats.

## Usage

To use this logging tool, all you need to do is install it:

```sh

yarn add structlog

```

And use it like so:

```js

import { logger } from 'structlog'

logger.error('error!')

```

Importing `logger` will give you a ready-made instance of `StructuredLogger` with the default config, so you don't need to instantiate a new logger instance each time or pass down references to an instance.

However, you can configure options by instantiating `StructuredLogger` yourself, like so:

```js

import { StructuredLogger } from 'structlog'

const logger = new StructuredLogger({ timestampFormat: 'unix' })

```

### Options 

You can configure the following options by passing them in an object as a parameter when creating `StructuredLogger` :

| Option | Default value | Accepted values | Description |

| :--: | :--: | :--: | :--: | 

| `timestampFormat` | `'iso'` | `'iso'` , `'gmt'`, `'unix'`, `'timestring'` ,`'localestring'` | Timestamp format to use. |

| `logFormat` | `'{timestamp} [{type}] {message} [{path}] {tags}'` | Any `string` | Log format to use `{}` to define variables. Accepted variables: `timestamp`, `type`, `message`, `path`, `tags`. |

| `pathFormat` | `'{filePath}:{lineNumber}'` | Any `string` | Format to use for the `path` component of the log. Use `{}` to define variables. Accepted variables: `filePath`, `lineNumber`, `functionName`, `methodName`, `typeName`. |

| `useColors` | `false` | `true`, `false` | Whether logs should be printed with colors according to the type (e.g. error = red). |

| `useThreadTagsExtension` | `false` | `true`, `false` | An extension that automatically adds a `thread` tag to the log specifying what thread the log happened in. |

| `useLogIdExtension` | `false` | `true`, `false` | An extension that automatically adds a `logId` tag to the log, with a unique ID as its value. |

| `pathStackDepth` | `0` | Any `number` | (_Advanced_) Level of depth to determine the path portion of the log from. For example, if you write a wrapper over the logger, set this to 1 so that the path will reflect the code that called your wrapper, rather than the wrapper itself.  |