kliedz/src/logger/colors.ts

Dead-simple, stateless logging utility for JavaScript and TypeScript. Pure functions. No dependencies. Just log.

import type { LogLevel } from "../types/log_level.js";

/**
 * ANSI color codes mapped to log levels for terminal output.
 * These control how the log prefix is rendered in supported terminals.
 */
const LEVEL_COLORS = Object.freeze({
	debug: "\x1b[90m", // gray
	info: "\x1b[36m", // cyan
	warn: "\x1b[33m", // yellow/orange
	error: "\x1b[31m", // red
} as const satisfies Record<LogLevel, string>);

export const RESET_COLOR = "\x1b[0m";

/**
 * Returns the ANSI color code for a given log level.
 * Throws if the level is unknown or not configured.
 *
 * @param level - The log level to get color for.
 * @returns ANSI escape code string for that level.
 */
export function getColorFor(level: LogLevel): string {
	if (!Object.hasOwn(LEVEL_COLORS, level)) {
		throw new Error(`Unknown log level: "${level}"`);
	}

	return LEVEL_COLORS[level];
}