const LOG_LEVELS = { error: 0, warn: 1, info: 2, debug: 3 } as const;
type LogLevel = keyof typeof LOG_LEVELS;
const envLevel = process.env.REPLICANT_LOG_LEVEL as string | undefined;
const currentLevel: LogLevel = envLevel && envLevel in LOG_LEVELS ? (envLevel as LogLevel) : "warn";
const useJson = process.env.REPLICANT_LOG_FORMAT === "json";
export const logger = {
error: (msg: string, ctx?: Record<string, unknown>) => log("error", msg, ctx),
warn: (msg: string, ctx?: Record<string, unknown>) => log("warn", msg, ctx),
info: (msg: string, ctx?: Record<string, unknown>) => log("info", msg, ctx),
debug: (msg: string, ctx?: Record<string, unknown>) => log("debug", msg, ctx),
};
function safeStringify(obj: Record<string, unknown>): string {
try {
return JSON.stringify(obj);
} catch {
return "[unserializable]";
}
}
function log(level: LogLevel, msg: string, ctx?: Record<string, unknown>) {
if (LOG_LEVELS[level] > LOG_LEVELS[currentLevel]) return;
if (useJson) {
try {
process.stderr.write(
JSON.stringify({ ...ctx, level, msg, ts: new Date().toISOString() }) + "\n",
);
} catch {
process.stderr.write(
JSON.stringify({ level, msg, ts: new Date().toISOString(), ctx: "[unserializable]" }) + "\n",
);
}
} else {
const ctxStr = ctx ? " " + safeStringify(ctx) : "";
process.stderr.write(`[${level.toUpperCase()}] ${msg}${ctxStr}\n`);
}
}
