@gvray/logger

---

@gvray/logger / Logger

Class: Logger

Defined in: Logger.ts:26

A lightweight, extensible logger with middleware, namespaces, and listeners.

Emits to the console (ANSI-colored in Node, CSS-styled in browsers) and supports a middleware pipeline for transforming logs before output, plus listeners for side effects like error collection or analytics.

Example

import { Logger, LogLevel } from '@gvray/logger';

const logger = new Logger({ level: LogLevel.DEBUG, timestamp: 'time' });
logger.info('Server started on port', 3000);

Constructors

Constructor

new Logger(options?): Logger

Defined in: Logger.ts:40

Create a new Logger instance.

Parameters

options?

LogOptions = {}

Configuration options. Omit for sensible defaults (level DEBUG, colors enabled, no namespace, no timestamp).

Returns

Logger

Methods

addListener()

addListener(listener): this

Defined in: Logger.ts:337

Add a listener invoked for every emitted log entry that passes the level filter. Useful for in-process side effects like error collection, statistics, or screen formatting.

Parameters

listener

LogListener

Returns

this

this, for chaining.

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child()

child(namespace): Logger

Defined in: Logger.ts:268

Create a child logger that inherits the parent's level, colors, timestamp format, and a copy of its middleware. The child's namespace is appended to the parent's using a : separator (e.g. app → app:http).

Parameters

namespace

string

Namespace segment for the child.

Returns

Logger

A new child Logger.

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debug()

debug(...args): void

Defined in: Logger.ts:218

Log at LogLevel.DEBUG.

Parameters

args

...unknown[]

Returns

void

---

disableColors()

disableColors(): this

Defined in: Logger.ts:314

Disable ANSI color output.

Returns

this

this, for chaining.

---

enableColors()

enableColors(): this

Defined in: Logger.ts:304

Enable ANSI color output.

Returns

this

this, for chaining.

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error()

error(...args): void

Defined in: Logger.ts:238

Log at LogLevel.ERROR.

Parameters

args

...unknown[]

Returns

void

---

fatal()

fatal(...args): void

Defined in: Logger.ts:243

Log at LogLevel.FATAL.

Parameters

args

...unknown[]

Returns

void

---

getLevel()

getLevel(): LogLevel

Defined in: Logger.ts:295

Get the current minimum log level.

Returns

LogLevel

---

info()

info(...args): void

Defined in: Logger.ts:223

Log at LogLevel.INFO.

Parameters

args

...unknown[]

Returns

void

---

removeListener()

removeListener(listener): this

Defined in: Logger.ts:347

Remove a previously registered listener.

Parameters

listener

LogListener

Returns

this

this, for chaining.

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setLevel()

setLevel(level): this

Defined in: Logger.ts:287

Set the minimum log level. Messages below this level are not output.

Parameters

level

LogLevel

Returns

this

this, for chaining.

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setTimestamp()

setTimestamp(format): this

Defined in: Logger.ts:325

Set the timestamp format. Pass true for ISO, a string for a built-in format, false to disable, or a function for custom formatting.

Parameters

format

boolean | TimestampFormat

Returns

this

this, for chaining.

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silent()

silent(): this

Defined in: Logger.ts:359

Disable all log output by setting the level to LogLevel.SILENT. Listeners still receive entries whose level is >= SILENT (i.e. none, since SILENT is the maximum).

Returns

this

this, for chaining.

---

trace()

trace(...args): void

Defined in: Logger.ts:213

Log at LogLevel.TRACE.

Parameters

args

...unknown[]

Returns

void

---

use()

use(middleware): this

Defined in: Logger.ts:255

Register a middleware in the logging pipeline.

Middleware run in registration order on every log call. Mutate ctx.args and call next() to forward the log downstream.

Parameters

middleware

LogMiddleware

Returns

this

this, for chaining.

---

warn()

warn(...args): void

Defined in: Logger.ts:233

Alias for warning.

Parameters

args

...unknown[]

Returns

void

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warning()

warning(...args): void

Defined in: Logger.ts:228

Log at LogLevel.WARNING.

Parameters

args

...unknown[]

Returns

void