Debug UtilitiesAPI reference for debugging, logging, and error handling utility functionsbugAPI Reference
Categories

Debug Utilities

The Debug utilities provide functions for logging, debugging, and enhanced error handling in JavaScript.

Functions

log

function log(message, level = 'log', { namespace = '', data = undefined, color = 'inherit', timestamp = false, format = 'standard', consoleMethod = null, silent = false, title = toTitleCase(namespace), showTitle = true, titleColor = null } = {})

A flexible logging utility with formatting, namespacing, and multiple output options. Supports colored output, timestamps, structured JSON format, and configurable titles.

Parameters

Name Type Description
message string The message to log
level string Log level (‘debug’, ‘log’, ‘info’, ‘warn’, ‘error’)
options object Optional configuration
Options
Name Type Default Description
namespace string ‘’ Namespace for grouping related logs (used as default title)
data any undefined Additional data to include with the log message. Accepts arrays and objects
color string ‘inherit’ Text color for the message
timestamp boolean false Whether to include timestamp in the output
format string ‘standard’ Output format (‘standard’ or ‘json’)
consoleMethod string null Override the console method used for output
silent boolean false Suppress all output when true
title string toTitleCase(namespace) Title/label to display before the message
showTitle boolean true Whether to show the title/label
titleColor string null Color for the title/label (defaults to level color)

Returns

This function does not return a value.

Example

import { log } from '@semantic-ui/utils';


// Basic usage
log('Application started', 'info');
log('Debug information', 'debug');


// With namespace and data
log('User login successful', 'info', {
  namespace: 'UserService',
  data: [{ userId: 123, timestamp: new Date() }]
});


// JSON format for structured logging
log('API response received', 'info', {
  format: 'json',
  namespace: 'ApiClient',
  timestamp: true,
  data: [{ status: 200, endpoint: '/api/users' }]
});


// Custom styling
log('Important notice', 'warn', {
  title: 'NOTICE',
  titleColor: '#FF6B35',
  timestamp: true
});

fatal

function fatal(message, { errorType = Error, metadata = {}, onError = null, removeStackLines = 1 } = {})

Throws an error with enhanced control over the error type, metadata, and stack trace.

Asynchronous Error Throwing This function uses queueMicrotask to throw the error asynchronously, allowing the current execution context to complete.

Parameters

Name Type Description
message string The error message
options object Optional configuration
Options
Name Type Default Description
errorType function Error The type of error to throw
metadata object Additional data to attach to the error
onError function null Callback to intercept the error. When provided, the error is passed to this callback and the throw is prevented
removeStackLines number 1 Number of stack trace lines to remove

Example

import { fatal } from '@semantic-ui/utils';


// Throws asynchronously via queueMicrotask
fatal("Something went wrong", {
  errorType: TypeError,
  metadata: { code: "ERR_001" },
});


// Using onError to intercept and prevent the throw
fatal("Handled error", {
  onError: (err) => console.log("Intercepted:", err.message)
});
Previous
Dates
Next
Environment