logging

Workbench Core Logging

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Description

An extendable logging service

Create a LoggingService Instance

Create a LoggingService instance using new LoggingService().

const logger = new LoggingService({
    maxLogLevel: 'warn',
    includeLocation: false,
    metadata: {
        serviceName: 'example service'
    }
});

Logging Messages

Messages can be logged using any of the log level methods.

//
// Any LoggingService instance
//
instance.error('This is an error message');
instance.warn('This is a warning message');
instance.info('This is an info message');
instance.http('This is an http message');
instance.verbose('This is a verbose message');
instance.debug('This is a debug message');
instance.silly('This is a silly message');

Messages are of the LogMessage type.

//
// Any LoggingService instance
//
instance.error(404);
instance.warn('This is a warning message');
instance.info(infoObject);

A LogMessageObject can also be added to log messages. If it is, the message parameter must be a string.

//
// Any LoggingService instance
//
instance.info('This is an error message', infoObject);

Example

Input:

const logger = new LoggingService({
    maxLogLevel: 'debug',
    defaultMetadata: {
        serviceName: 'example service'
    }
});

logger.warn("warning message");

logger.info({
    parameters: ["param1", 123, false],
    extra: "information"
});

logger.error("Log message", {
    parameters: ["param1", 123, false],
    extra: "information"
});

Output:

{
    "level": "warn",
    "location": "someFunction someFile:lineNumber",
    "message": "warning message",
    "meta": {
        "serviceName": "example service"
    }
}

{
    "level": "info",
    "location": "someFunction someFile:lineNumber",
    "message": {
        "extra": "information",
        "parameters": ["param1", 123, false]
    },
    "meta": {
        "serviceName": "example service"
    }
}


{
    "extra": "information",
    "level": "error",
    "location": "someFunction someFile:lineNumber",
    "message": "Log message",
    "meta": {
        "serviceName": "example service"
    },
    "parameters": ["param1", 123, false]
}

Extending LoggingService

LoggingService uses WinstonPlugin as the default LoggingPlugin but can be replaced with a user-provided plugin. User-provided plugin must meet the following criteria:

• Implement the LoggingPlugin interface
• Implement the following log levels and their priorities (highest to lowest)
  • error: 0
  • warn: 1
  • info: 2
  • http: 3
  • verbose: 4
  • debug: 5
  • silly: 6
• Handle ignoring logs with log levels higher than the log level set with setMaxLogLevel()

Extending WinstonPlugin

WinstonPlugin uses ConsoleTransport as the default transport but can be replaced with a user-provided transport (or multiple transports). User-provided transports must extend the TransportStream class from the winston-transport npm package found here.