@wgtechlabs/log-engine
Version:
A lightweight, security-first logging utility with automatic data redaction for Node.js applications - the first logging library with built-in PII protection.
133 lines • 6.14 kB
JavaScript
/**
* Core message formatting functionality
* Handles the main log message formatting with colors, timestamps, and levels
*/
import { LogLevel } from '../types/index.js';
import { colors, colorScheme } from './colors.js';
import { getTimestampComponents, formatTimestamp } from './timestamp.js';
import { formatData, styleData } from './data-formatter.js';
/**
* Core message formatter class
* Provides the main formatting functionality for log messages
*/
export class MessageFormatter {
/**
* Formats a log message with timestamp, level indicator, and appropriate coloring
* Creates a structured log entry: [ISO_TIMESTAMP][LOCAL_TIME][LEVEL]: message [data]
* @param level - The log level to format for
* @param message - The message content to format
* @param data - Optional data object to include in the log output
* @param formatConfig - Optional format configuration to control element inclusion
* @returns Formatted string with ANSI colors and timestamps
*/
static format(level, message, data, formatConfig) {
// Merge provided format configuration with the default configuration
const config = {
...MessageFormatter.DEFAULT_FORMAT_CONFIG,
...formatConfig
};
// Build timestamp string conditionally
let timestamp = '';
if (config.includeIsoTimestamp || config.includeLocalTime) {
const { isoTimestamp, timeString } = getTimestampComponents();
if (config.includeIsoTimestamp && config.includeLocalTime) {
// Both timestamps included
timestamp = formatTimestamp(isoTimestamp, timeString, colorScheme);
}
else if (config.includeIsoTimestamp) {
// Only ISO timestamp
timestamp = `${colorScheme.timestamp}[${isoTimestamp}]${colors.reset}`;
}
else if (config.includeLocalTime) {
// Only local time
timestamp = `${colorScheme.timeString}[${timeString}]${colors.reset}`;
}
}
const levelName = MessageFormatter.getLevelName(level);
const levelColor = MessageFormatter.getLevelColor(level);
const coloredLevel = `${levelColor}[${levelName}]${colors.reset}`;
// Format the base message (level is always included as per requirements)
let formattedMessage = `${timestamp}${coloredLevel}: ${message}`;
// Append data if provided
if (data !== undefined) {
const dataString = formatData(data);
const styledData = styleData(dataString, colorScheme);
formattedMessage += styledData;
}
// Always reset colors at the end of the entire log line
return formattedMessage + colors.reset;
}
/**
* Formats a Log Engine system message with [LOG ENGINE] prefix instead of log levels
* Used for internal messages like deprecation warnings that should be distinguished from user logs
* @param message - The system message content to format
* @param formatConfig - Optional format configuration to control element inclusion
* @returns Formatted string with ANSI colors, timestamps, and LOG ENGINE prefix
*/
static formatSystemMessage(message, formatConfig) {
// Merge provided format configuration with the default configuration
const config = {
...MessageFormatter.DEFAULT_FORMAT_CONFIG,
...formatConfig
};
// Build timestamp string conditionally
let timestamp = '';
if (config.includeIsoTimestamp || config.includeLocalTime) {
const { isoTimestamp, timeString } = getTimestampComponents();
if (config.includeIsoTimestamp && config.includeLocalTime) {
// Both timestamps included
timestamp = formatTimestamp(isoTimestamp, timeString, colorScheme);
}
else if (config.includeIsoTimestamp) {
// Only ISO timestamp
timestamp = `${colorScheme.timestamp}[${isoTimestamp}]${colors.reset}`;
}
else if (config.includeLocalTime) {
// Only local time
timestamp = `${colorScheme.timeString}[${timeString}]${colors.reset}`;
}
}
const coloredLogEngine = `${colorScheme.system}[LOG ENGINE]${colors.reset}`;
const coloredMessage = `${colorScheme.system}${message}${colors.reset}`;
return `${timestamp}${coloredLogEngine}: ${coloredMessage}`;
}
/**
* Converts LogLevel enum to human-readable string
* @param level - The LogLevel to convert
* @returns String representation of the log level
*/
static getLevelName(level) {
switch (level) {
case LogLevel.DEBUG: return 'DEBUG';
case LogLevel.INFO: return 'INFO';
case LogLevel.WARN: return 'WARN';
case LogLevel.ERROR: return 'ERROR';
case LogLevel.LOG: return 'LOG';
default: return 'UNKNOWN';
}
}
/**
* Maps LogLevel to appropriate ANSI color code
* Colors help quickly identify message severity in console output
* @param level - The LogLevel to get color for
* @returns ANSI color escape sequence
*/
static getLevelColor(level) {
switch (level) {
case LogLevel.DEBUG: return colors.magenta; // Purple for debug info
case LogLevel.INFO: return colors.blue; // Blue for general info
case LogLevel.WARN: return colors.yellow; // Yellow for warnings
case LogLevel.ERROR: return colors.red; // Red for errors
case LogLevel.LOG: return colors.green; // Green for always-on log messages
default: return colors.white; // White for unknown levels
}
}
}
/**
* Default format configuration to avoid object recreation on every call
*/
MessageFormatter.DEFAULT_FORMAT_CONFIG = {
includeIsoTimestamp: true,
includeLocalTime: true
};
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