Workleap Logging (@workleap/logging)

A structured logging library for Workleap frontend applications. Provides composable, styled console logging with support for scopes, multiple log levels, and integration with telemetry tools.

The library exports four key types: Logger (base interface), RootLogger (extends Logger with scope support), BrowserConsoleLogger, and CompositeLogger.

Installation

pnpm add @workleap/logging

Core Concepts

Loggers

BrowserConsoleLogger: Outputs to browser console with styling support
CompositeLogger: Forwards logs to multiple underlying loggers
createCompositeLogger(verbose, loggers): Factory function that creates a CompositeLogger. When verbose is true and no loggers are provided, it adds a BrowserConsoleLogger; otherwise it uses only the loggers you pass (an empty list produces no output). See references/api.md for details.

Log Levels (lowest to highest severity)

debug - Detailed diagnostic info for development
information - General application flow events
warning - Non-critical issues needing attention
error - Failures that prevent functionality from completing (triggers alerting in production)
critical - Severe errors risking data integrity

Scopes

Scopes buffer log entries in memory and output them as a grouped block when .end() is called. This makes it easier to trace multi-step operations in noisy console output.

const scope = logger.startScope("User signup");
scope.debug("Validating...");
scope.information("Signup complete");
scope.end();

The Logger interface doesn't expose startScope because scoping is a root-level concern. When using Squide's useLogger(), the return type is Logger, so cast to RootLogger to access scope methods:

import { useLogger } from "@squide/firefly";
import type { RootLogger } from "@workleap/logging";

const logger = useLogger();
(logger as RootLogger).startScope("User signup");

Chained Segments

Build complex log entries by chaining segments. A chain without a terminal log level method (.debug(), .error(), etc.) silently produces no output — this is the most common source of missing logs.

logger
    .withText("Processing order")
    .withObject({ orderId: 123 })
    .withError(new Error("Failed"))
    .error();
// Output: [error] Processing order { orderId: 123 } Error: Failed

Common Pitfalls

Forgetting the terminal log method: Chained segments without .debug(), .error(), etc. silently produce no output.
Not ending scopes: Scoped entries are buffered in memory and only flushed to the console when .end() is called. Without it, the logs are silently lost.
Using warning for failures: Reserve error for failures — warning is for non-critical issues. This distinction matters because production alerting and log filtering depend on accurate severity.
Logging sensitive data: Log entries may appear in LogRocket session replays and browser dev tools, so including credentials or PII creates compliance and security exposure.
Missing error context: Without withObject() for relevant data and withError() for exceptions, error logs lack the information needed to reproduce issues in production.

Reference Guide

references/api.md — Read when you need constructor signatures, the full method list (styled text, line breaks, withObject, withError), scope lifecycle API, or createCompositeLogger details.
references/patterns.md — Read when setting up a logger from scratch, integrating with LogRocket, implementing scoped logging for features/operations, or conducting a PR review of logging code.

workleap-logging