feat: add winston-based logger

src/logging/WinstonLogger.ts

@@ -0,0 +1,19 @@
+import type { Logger as WinstonInnerLogger } from 'winston';
+import type { Logger } from './Logger';
+import type { LogLevel } from './LogLevel';
+
+/**
+ * A WinstonLogger implements the {@link Logger} interface using a given winston logger.
+ */
+export class WinstonLogger implements Logger {
+  private readonly logger: WinstonInnerLogger;
+
+  public constructor(logger: WinstonInnerLogger) {
+    this.logger = logger;
+  }
+
+  public log(level: LogLevel, message: string, meta?: any): this {
+    this.logger.log(level, message, meta);
+    return this;
+  }
+}

src/logging/WinstonLoggerFactory.ts

@@ -0,0 +1,37 @@
+import { createLogger, format, transports } from 'winston';
+import type * as Transport from 'winston-transport';
+import type { Logger } from './Logger';
+import type { LoggerFactory } from './LoggerFactory';
+import { WinstonLogger } from './WinstonLogger';
+
+/**
+ * Uses the winston library to create loggers for the given logging level.
+ * By default, it will print to the console with colorized logging levels.
+ *
+ * This creates instances of {@link WinstonLogger}.
+ */
+export class WinstonLoggerFactory implements LoggerFactory {
+  private readonly level: string;
+
+  public constructor(level: string) {
+    this.level = level;
+  }
+
+  public createLogger(label: string): Logger {
+    return new WinstonLogger(createLogger({
+      level: this.level,
+      format: format.combine(
+        format.label({ label }),
+        format.colorize(),
+        format.timestamp(),
+        format.printf(({ level: levelInner, message, label: labelInner, timestamp }: {[key: string]: any}): string =>
+          `${timestamp} [${labelInner}] ${levelInner}: ${message}`),
+      ),
+      transports: this.createTransports(),
+    }));
+  }
+
+  protected createTransports(): Transport[] {
+    return [ new transports.Console() ];
+  }
+}