Class: Logger

A generalized application logger implementation for Node.JS applications

Constructors

Constructor

new Logger(
   level:
  | LoggerLevel
  | "DEBUG"
  | "INFO"
  | "ERROR"
  | "EMERG"
  | "ALERT"
  | "CRIT"
  | "WARNING"
  | "NOTICE",
   meta: Record<string, any>,
   options?: LoggerTransportOptions): Logger;

Create a new logger instance.

Parameters

Parameter	Type	Default value	Description
level	| LoggerLevel | "DEBUG" | "INFO" | "ERROR" | "EMERG" | "ALERT" | "CRIT" | "WARNING" | "NOTICE"	'info'	The log level to use. This can be any of the levels defined in LoggerLevel.
meta	Record<string, any>	{}	Additional metadata to include in the log messages. This can be any object.
options?	LoggerTransportOptions	undefined	Transport options. May contain console and/or loki configuration.

Returns

Logger

Accessors

complete

Get Signature

get complete(): Promise<void>;

A promise that resolves when the logger has finished processing all log messages.

Returns

Promise<void>

Methods

alert()

alert(...args: any[]): void;

Log a message with the level of alert

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

child()

child(meta: Record<string, any>): Logger;

Return a new logger instance with the same level and additional metadata.

Parameters

Parameter	Type	Description
meta	Record<string, any>	Additional metadata to include in the log messages. This can be any object.

Returns

Logger

A new logger instance with the same level and additional metadata.

---

close()

close(): void;

Close the logger and flush any remaining log messages.

Returns

void

---

crit()

crit(...args: any[]): void;

Log a message with the level of crit

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

debug()

debug(...args: any[]): void;

Log a message with the level of debug

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

emerg()

emerg(...args: any[]): void;

Log a message with the level of emerg

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

error()

error(...args: any[]): void;

Log a message with the level of error

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

info()

info(...args: any[]): void;

Log a message with the level of info

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

inspect()

inspect(arg: unknown, level:
  | LoggerLevel
  | "DEBUG"
  | "INFO"
  | "ERROR"
  | "EMERG"
  | "ALERT"
  | "CRIT"
  | "WARNING"
  | "NOTICE"): void;

Log an inspected value using the Node.js util.inspect function.

Parameters

Parameter	Type	Default value	Description
arg	unknown	undefined	The value to inspect.
level	| LoggerLevel | "DEBUG" | "INFO" | "ERROR" | "EMERG" | "ALERT" | "CRIT" | "WARNING" | "NOTICE"	'info'	The log level to use. This can be any of the levels defined in LoggerLevel.

Returns

void

---

notice()

notice(...args: any[]): void;

Log a message with the level of notice

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

shutdown()

shutdown(): Promise<void>;

Shuts down the logger and flushes any remaining log messages.

Returns

Promise<void>

---

warning()

warning(...args: any[]): void;

Log a message with the level of warning

Parameters

Parameter	Type	Description
...args	any[]	The arguments to log

Returns

void

---

withContext()

withContext(context: LogContext): Logger;

Return a new logger instance carrying the supplied LogContext fields on every record. Equivalent to Logger.child but typed against the standard structured-context fields (correlationId, requestId, tenantId, traceId, spanId, userId, module).

Prefer this over Logger.child for cross-cutting observability fields so the field names stay consistent across services.

Parameters

Parameter	Type
context	LogContext

Returns

Logger

Example

const reqLogger = logger.withContext({ requestId, tenantId, correlationId });
reqLogger.info("checkout intent created");