Class Logger

A custom Logger class that provides enhanced logging capabilities with log levels, scoping, and formatting.

It wraps around the native console methods and adds features like colored output, timestamps, and grouping. The log level can be configured globally or per instance, allowing for flexible logging based on the environment or specific needs.

See

getLogLevel for details on how log levels are determined and configured.

Example usage:

const logger = new Logger('MyApp', 'info');
logger.debug('This is a debug message'); // Will not be logged due to log level
logger.info('This is an info message'); // Will be logged with timestamp and scope
logger.warn('This is a warning'); // Will be logged with timestamp and scope
logger.error('This is an error'); // Will be logged with timestamp and scope

Index

Constructors

constructor

Methods

assert clear count countReset debug dir dirxml error getScope group groupCollapsed groupEnd info log profile profileEnd setLogLevel setScope table time timeEnd timeLog timeStamp trace warn

Constructors

constructor

new Logger(): Logger
Create a new default logger instance with default log level

Returns Logger
- Defined in index.ts:411
new Logger(scope: string): Logger
Creates a new logger instance with the specified scope.

The scope is a string that will be prefixed to all log messages from this Logger instance, allowing for easier identification of the source of log messages The scope can also be set or changed later using the Logger.setScope method.
Parameters
- scope: string
  Sets the scope for this Logger instance, which will be prefixed to all log messages. If an empty string is provided, no scope will be used.
Returns Logger
Remarks
This constructor cannot be used to name the scope with the same name as a log level (e.g. info, warn, error) to avoid confusion with log level configuration. If such a name is used, it will be treated as a log level configuration instead of a scope, and the scope will default to an empty string.

See
Logger.setScope for details on how scope is determined and configured.
- Defined in index.ts:426
new Logger(logLevel: LogLevelString | Partial<LogLevel>): Logger
Creates a new logger instance with the specified log level.

If a string is provided, it will be processed according to the rules defined in the getLogLevel function If a Partial<LogLevel> object is provided, it will override the corresponding log levels while keeping the others at their default values.
Parameters
- logLevel: LogLevelString | Partial<LogLevel>
  the log level to set for this Logger instance. This can be a string representing the desired log level or a Partial object to specify individual log levels. If a string is provided, it will be processed according to the rules defined in the getLogLevel function, which also considers environment variables for configuration. If a Partial object is provided, it will override the corresponding log levels while keeping the others at their default or previously set values.
Returns Logger
See
getLogLevel for details on how log levels are determined and configured.
- Defined in index.ts:436
new Logger(scope: string, logLevel: LogLevelString | Partial<LogLevel>): Logger
Create a new logger instance with the specified scope and log level.

The scope is a string that will be prefixed to all log messages from this Logger instance, allowing for easier identification of the source of log messages. The scope can also be set or changed later using the Logger.setScope method.

If a string is provided, it will be processed according to the rules defined in the getLogLevel function If a Partial<LogLevel> object is provided, it will override the corresponding log levels while keeping the others at their default values.
Parameters
- scope: string
  Scope name
- logLevel: LogLevelString | Partial<LogLevel>
  The logLevel for this Logger instance
Returns Logger
See
Logger.setScope for details on how scope is determined and configured.
- Defined in index.ts:451

Methods

assert

assert(condition: boolean, ...data: unknown[]): void
Assert the condition and log the data if assertion fails.

If condition is true no message will be logged

Log level: errors
Parameters
- condition: boolean
  The condition to assert
- ...data: unknown[]
  The data to print if assertion fails
Returns void
- Defined in index.ts:495

clear

clear(): void
Clears the console

Returns void
Remarks
This method will clear all logs regardless of the log level and scope
- Defined in index.ts:507

count

count(label?: string): void
Increments the counter for the given label and logs it to the console.

Log level: info
Parameters
- label: string = 'default'
  The label for counter, default is default
Returns void
Remarks
The counter will not increment if log level is set to a level that does not include info (e.g. warn, error, none). If the counter for the given label does not exist, it will be initialized to 0 before being incremented. The log message will always automatically include the scope of the logger
- Defined in index.ts:523

countReset

countReset(label?: string): void
Resets the counter for the given label.

Log level: info
Parameters
- label: string = 'default'
  The label for the counter, default is default
Returns void
Remarks
The counter will not reset if log level is set to a level that does not include info (e.g. warn, error, none). If the counter for the given label does not exist, this method will have no effect. The counter log will always automatically include the scope of the logger
- Defined in index.ts:541

debug

debug(...data: unknown[]): void
Print a debug message

Log level: verbose
Parameters
- ...data: unknown[]
  The data to print
Returns void
- Defined in index.ts:584

dir

dir(
item: unknown,
options?: { colors?: boolean; depth?: boolean; showHidden?: boolean },
): void
This will print a given object using console.dir

Prints JSON data of an object

Log level: info
Parameters
- item: unknown
  The object to print
- Optionaloptions: { colors?: boolean; depth?: boolean; showHidden?: boolean }
  Options to pass to console.dir
Returns void
- Defined in index.ts:556

dirxml

dirxml(...data: unknown[]): void
This will print a given object using console.dirxml

Print XML data of an object

Log level: info
Parameters
- ...data: unknown[]
  The object to print
Returns void
- Defined in index.ts:571

error

error(...data: unknown[]): void
Print an error message

Log level: errors
Parameters
- ...data: unknown[]
  The data to print
Returns void
- Defined in index.ts:597

getScope

getScope(): string
Gets the current scope for this Logger instance.

Returns string
Scope name
- Defined in index.ts:404

group

group(label?: string): void
Start a new group

Log level: info
Parameters
- Optionallabel: string
  The group label
Returns void
Remarks
This will create a group regardless of the log level, but the group label will only be printed if log level includes info. The group is not ended automatically, so you need to call groupEnd to end the group. The groups are tracked regardless of the scope
- Defined in index.ts:615

groupCollapsed

groupCollapsed(label?: string): void
Start a new collapsed group

Collapsed groups don't include indentation for their content

Log level: info
Parameters
- Optionallabel: string
  The group label
Returns void
Remarks
This will create a collapsed group regardless of the log level, but the group label will only be printed if log level includes info. The group is not ended automatically, so you need to call groupEnd to end the group. The groups are tracked regardless of the scope
- Defined in index.ts:639

groupEnd

groupEnd(): void
End the current group

Log level: info

Returns void
Remarks
This will end the current group regardless of the log level, but the log message indicating the end of the group will only be printed if log level includes info. If there is no group to end, this method will have no effect. The groups are tracked regardless of the scope
- Defined in index.ts:659

info

info(...data: unknown[]): void
Print an info message

Log level: info
Parameters
- ...data: unknown[]
  The data to be printed
Returns void
- Defined in index.ts:676

log

log(...data: unknown[]): void
Log a message

Log level: info
Parameters
- ...data: unknown[]
  The data to be printed
Returns void
- Defined in index.ts:689

profile

profile(label?: string): void
Experimental
Start profiling with a given label

You can end profiling using the Logger.profileEnd method

Log level: info
Parameters
- label: string = 'default'
  The label for profiling, default is default
Returns void
Remarks
The label will automatically include the scope of the logger The profile will not start if log level is set to a level that does not include info (e.g. warn, error, none). This method uses performance.now() and not console.profile as the latter isn't currently implemented
- Defined in index.ts:710

profileEnd

profileEnd(label?: string): void
Experimental
End profiling with a given label and log the duration

You can start profiling using the Logger.profile method

Log level: info
Parameters
- label: string = 'default'
  The label for profiling, default is default
Returns void
Remarks
The label will always automatically include the scope of the logger The profile will not end if log level is set to a level that does not include info (e.g. warn, error, none). If no active profile with the given label is found, a warning message will be logged instead This method uses performance.now() and not console.profileEnd as the latter isn't currently implemented.
- Defined in index.ts:736

setLogLevel

setLogLevel(logLevel: LogLevelString | Partial<LogLevel>): void
Sets the log level for this Logger instance
Parameters
- logLevel: LogLevelString | Partial<LogLevel>
  The log level to set
Returns void
See
getLogLevel for details on how log levels are determined and configured.
- Defined in index.ts:384

setScope

setScope(scope: string): void
Sets the scope for this Logger instance, which will be prefixed to all log messages.

If an empty string is provided, no scope will be used.
Parameters
- scope: string
  Scope name
Returns void
- Defined in index.ts:395

table

table(data: Record<string, unknown>[], columns?: string[]): void
Print a table to the console

Log level: info
Parameters
- data: Record<string, unknown>[]
  The data for table
- Optionalcolumns: string[]
  The columns to include in the table, if not provided all columns will be included
Returns void
- Defined in index.ts:762
table(data: unknown[]): void
Print a table to the console

Log level: info
Parameters
- data: unknown[]
  The data to be printed
Returns void
- Defined in index.ts:770

time

time(label?: string): void
Start a timer with the given label

The timer can be ended using the Logger.timeEnd method. The Logger.timeLog method can be used to log the current duration without ending the timer.

Log level: info
Parameters
- label: string = 'default'
  Label for measuring time, default is default
Returns void
Remarks
The timer label will automatically include the scope of the logger. The timer will not start if log level is set to a level that does not include info (e.g. warn, error, none). If a timer with the same label already exists, it will be overwritten with the new start time.
- Defined in index.ts:792

timeEnd

timeEnd(label?: string): void
End a timer with the given label

If there is no active timer with the given label, this method will have no effect. The timer can be started using the Logger.time method, and the current duration can be logged without ending the timer using the Logger.timeLog method.

Log level: info
Parameters
- label: string = 'default'
  The label for measuring time, default is default
Returns void
Remarks
The timer label will automatically include the scope of the logger. The timer will not end if log level is set to a level that does not include info (e.g. warn, error, none).
- Defined in index.ts:812

timeLog

timeLog(label?: string): void
Log current duration of a timer with the given label without ending the timer

If there is no active timer with the given label, this method will have no effect. The timer can be started using the Logger.time method, and it can be ended using the Logger.timeEnd method.

Log level: info
Parameters
- label: string = 'default'
  The label for measuring time, default is default
Returns void
Remarks
The timer label will automatically include the scope of the logger. The timer will not log if log level is set to a level that does not include info (e.g. warn, error, none).
- Defined in index.ts:831

timeStamp

timeStamp(label?: string): void
Experimental
This doesn't do anything at the moment

Passed the label to console.timeStamp
Parameters
- label: string = 'default'
Returns void
Remarks
The label will automatically include the scope of the logger.
- Defined in index.ts:847

trace

trace(...data: unknown[]): void
Print a stack trace with the given data

Log level: verbose
Parameters
- ...data: unknown[]
  The data to be printed
Returns void
Remarks
The stack trace might be indented incorectly The stack tree will include the logger implementation
- Defined in index.ts:863

warn

warn(...data: unknown[]): void
Print a warning message

Log level: warnings
Parameters
- ...data: unknown[]
  The data to be printed
Returns void
- Defined in index.ts:876

Class Logger

See

Index

Constructors

Methods

Constructors

constructor

Returns Logger

Parameters

Returns Logger

Remarks

See

Parameters

Returns Logger

See

Parameters

Returns Logger

See

Methods

assert

Parameters

Returns void

clear

Returns void

Remarks

count

Parameters

Returns void

Remarks

countReset

Parameters

Returns void

Remarks

debug

Parameters

Returns void

dir

Parameters

Returns void

dirxml

Parameters

Returns void

error

Parameters

Returns void

getScope

Returns string

group

Parameters

Returns void

Remarks

groupCollapsed

Parameters

Returns void

Remarks

groupEnd

Returns void

Remarks

info

Parameters

Returns void

log

Parameters

Returns void

profile

Parameters

Returns void

Remarks

profileEnd

Parameters

Returns void

Remarks

setLogLevel

Parameters

Returns void

See

setScope

Parameters

Returns void

table