logger.ts•1.4 kB
export type LogLevel = "debug" | "info" | "warn" | "error";
interface LogEntry {
timestamp: string;
level: LogLevel;
message: string;
[key: string]: any;
}
export class Logger {
constructor(
private level: LogLevel = "info",
private format: "json" | "pretty" = "json",
) {}
private shouldLog(level: LogLevel): boolean {
const levels: LogLevel[] = ["debug", "info", "warn", "error"];
return levels.indexOf(level) >= levels.indexOf(this.level);
}
private log(level: LogLevel, message: string, metadata?: object): void {
if (!this.shouldLog(level)) {
return;
}
const entry: LogEntry = {
timestamp: new Date().toISOString(),
level,
message,
...metadata,
};
if (this.format === "json") {
console.log(JSON.stringify(entry));
} else {
const meta = metadata ? ` ${JSON.stringify(metadata)}` : "";
console.log(
`[${entry.timestamp}] ${level.toUpperCase()}: ${message}${meta}`,
);
}
}
debug(message: string, metadata?: object): void {
this.log("debug", message, metadata);
}
info(message: string, metadata?: object): void {
this.log("info", message, metadata);
}
warn(message: string, metadata?: object): void {
this.log("warn", message, metadata);
}
error(message: string, metadata?: object): void {
this.log("error", message, metadata);
}
}