refactor to check log levels

This will eventually allow the log level to be configured. For now,
the explicit debug flag does not work.

packages/backend/src/services/logger.ts

@@ -12,7 +12,14 @@ type Domain = {
 	color?: KEYWORD;
 };
 
-type Level = 'error' | 'success' | 'warning' | 'debug' | 'info';
+export const LEVELS = {
+	error: 0,
+	warning: 1,
+	success: 2,
+	info: 3,
+	debug: 4,
+};
+export type Level = LEVELS[keyof LEVELS];
 
 /**
  * Class that facilitates recording log messages to the console and optionally a syslog server.
@@ -22,6 +29,10 @@ export default class Logger {
 	private parentLogger: Logger | null = null;
 	private store: boolean;
 	private syslogClient: SyslogPro.RFC5424 | null = null;
+	/**
+	 * Messages below this level will be discarded.
+	 */
+	private minLevel: Level;
 
 	/**
 	 * Create a logger instance.
@@ -29,12 +40,13 @@ export default class Logger {
 	 * @param color Log message color
 	 * @param store Whether to store messages
 	 */
-	constructor(domain: string, color?: KEYWORD, store = true) {
+	constructor(domain: string, color?: KEYWORD, store = true, minLevel: Level = LEVELS.info) {
 		this.domain = {
 			name: domain,
 			color,
 		};
 		this.store = store;
+		this.minLevel = minLevel;
 
 		if (config.syslog) {
 			this.syslogClient = new SyslogPro.RFC5424({
@@ -58,16 +70,29 @@ export default class Logger {
 	 * @param store Whether to store messages
 	 * @returns A Logger instance whose parent logger is this instance.
 	 */
-	public createSubLogger(domain: string, color?: KEYWORD, store = true): Logger {
+	public createSubLogger(domain: string, color?: KEYWORD, store = true, minLevel: Level = LEVELS.info): Logger {
-		const logger = new Logger(domain, color, store);
+		const logger = new Logger(domain, color, store, minLevel);
 		logger.parentLogger = this;
 		return logger;
 	}
 
+	/**
+	 * Log a message.
+	 * @param level Indicates the level of this particular message. If it is
+	 *     less than the minimum level configured, the message will be discarded.
+	 * @param message The message to be logged.
+	 * @param important Whether to highlight this message as especially important.
+	 * @param subDomains Names of sub-loggers to be added.
+	 */
 	private log(level: Level, message: string, data?: Record<string, any> | null, important = false, subDomains: Domain[] = [], _store = true): void {
 		if (envOption.quiet) return;
-		const store = _store && this.store && (level !== 'debug');
+		const store = _store && this.store;
 
+		// Check against the configured log level.
+		if (level < this.minLevel) return;
+
+		// If this logger has a parent logger, delegate the actual logging to it,
+		// so the parent domain(s) will be logged properly.
 		if (this.parentLogger) {
 			this.parentLogger.log(level, message, data, important, [this.domain].concat(subDomains), store);
 			return;
@@ -75,36 +100,55 @@ export default class Logger {
 
 		const time = dateFormat(new Date(), 'HH:mm:ss');
 		const worker = cluster.isPrimary ? '*' : cluster.worker?.id;
-		const l =
-			level === 'error' ? important ? chalk.bgRed.white('ERR ') : chalk.red('ERR ') :
-			level === 'warning' ? chalk.yellow('WARN') :
-			level === 'success' ? important ? chalk.bgGreen.white('DONE') : chalk.green('DONE') :
-			level === 'debug' ? chalk.gray('VERB') :
-			chalk.blue('INFO');
 		const domains = [this.domain].concat(subDomains).map(d => d.color ? chalk.rgb(...convertColor.keyword.rgb(d.color))(d.name) : chalk.white(d.name));
-		const m =
-			level === 'error' ? chalk.red(message) :
-			level === 'warning' ? chalk.yellow(message) :
-			level === 'success' ? chalk.green(message) :
-			level === 'debug' ? chalk.gray(message) :
-			message;
 
-		let log = `${l} ${worker}\t[${domains.join(' ')}]\t${m}`;
+		let levelDisplay;
+		let messageDisplay;
+		switch (level) {
+			case LEVELS.error:
+				if (important) {
+					levelDisplay = chalk.bgRed.white('ERR ');
+				} else {
+					levelDisplay = chalk.red('ERR ');
+				}
+				messageDisplay = chalk.red(message);
+				break;
+			case LEVELS.warning:
+				levelDisplay = chalk.yellow('WARN');
+				messageDisplay = chalk.yellow(message);
+				break;
+			case LEVELS.success:
+				if (important) {
+					levelDisplay = chalk.bgGreen.white('DONE');
+				} else {
+					levelDisplay = chalk.green('DONE');
+				}
+				messageDisplay = chalk.green(message);
+				break;
+			case LEVELS.info:
+				levelDisplay = chalk.blue('INFO');
+				messageDisplay = message;
+				break;
+			case LEVELS.debug: default:
+				levelDisplay = chalk.gray('VERB');
+				messageDisplay = chalk.gray(message);
+				break;
+		}
+
+		let log = `${levelDisplay} ${worker}\t[${domains.join(' ')}]\t${messageDisplay}`;
 		if (envOption.withLogTime) log = chalk.gray(time) + ' ' + log;
 
 		console.log(important ? chalk.bold(log) : log);
 
-		if (store) {
+		if (store && this.syslogClient) {
-			if (this.syslogClient) {
 			const send =
-					level === 'error' ? this.syslogClient.error :
+				level === LEVELS.error ? this.syslogClient.error :
-					level === 'warning' ? this.syslogClient.warning :
+				level === LEVELS.warning ? this.syslogClient.warning :
 				this.syslogClient.info;
 
 			send.bind(this.syslogClient)(message).catch(() => {});
 		}
 	}
-	}
 
 	/**
 	 * Log an error message.
@@ -116,11 +160,11 @@ export default class Logger {
 	public error(err: string | Error, data: Record<string, any> = {}, important = false): void {
 		if (err instanceof Error) {
 			data.e = err;
-			this.log('error', err.toString(), data, important);
+			this.log(LEVELS.error, err.toString(), data, important);
 		} else if (typeof err === 'object') {
-			this.log('error', `${(err as any).message || (err as any).name || err}`, data, important);
+			this.log(LEVELS.error, `${(err as any).message || (err as any).name || err}`, data, important);
 		} else {
-			this.log('error', `${err}`, data, important);
+			this.log(LEVELS.error, `${err}`, data, important);
 		}
 	}
 
@@ -132,7 +176,7 @@ export default class Logger {
 	 * @param important Whether this warning is important
 	 */
 	public warn(message: string, data?: Record<string, any> | null, important = false): void {
-		this.log('warning', message, data, important);
+		this.log(LEVELS.warning, message, data, important);
 	}
 
 	/**
@@ -143,7 +187,7 @@ export default class Logger {
 	 * @param important Whether this success message is important
 	 */
 	public succ(message: string, data?: Record<string, any> | null, important = false): void {
-		this.log('success', message, data, important);
+		this.log(LEVELS.success, message, important);
 	}
 
 	/**
@@ -154,9 +198,7 @@ export default class Logger {
 	 * @param important Whether this debug message is important
 	 */
 	public debug(message: string, data?: Record<string, any> | null, important = false): void {
-		if (process.env.NODE_ENV !== 'production' || envOption.verbose) {
+		this.log(LEVELS.debug, message, data, important);
-			this.log('debug', message, data, important);
-		}
 	}
 
 	/**
@@ -167,6 +209,6 @@ export default class Logger {
 	 * @param important Whether this info message is important
 	 */
 	public info(message: string, data?: Record<string, any> | null, important = false): void {
-		this.log('info', message, data, important);
+		this.log(LEVELS.info, message, data, important);
 	}
 }