release: WRNexusJS 0.8.0

packages/observability/src/logging.ts

@@ -0,0 +1,79 @@
+export type LogLevel = "debug" | "info" | "warn" | "error";
+
+export interface LogRecord {
+  timestamp: string;
+  level: LogLevel;
+  message: string;
+  service: string;
+  traceId?: string;
+  spanId?: string;
+  requestId?: string;
+  attributes: Record<string, unknown>;
+}
+
+export interface StructuredLogger {
+  log(level: LogLevel, message: string, attributes?: Record<string, unknown>): void;
+  debug(message: string, attributes?: Record<string, unknown>): void;
+  info(message: string, attributes?: Record<string, unknown>): void;
+  warn(message: string, attributes?: Record<string, unknown>): void;
+  error(message: string, attributes?: Record<string, unknown>): void;
+  child(attributes: Record<string, unknown>): StructuredLogger;
+}
+
+export interface StructuredLoggerOptions {
+  service?: string;
+  level?: LogLevel;
+  now?: () => Date;
+  sink?: (record: LogRecord, line: string) => void;
+  redact?: readonly string[];
+  attributes?: Record<string, unknown>;
+}
+
+const LEVELS: Record<LogLevel, number> = { debug: 10, info: 20, warn: 30, error: 40 };
+
+function scrub(value: Record<string, unknown>, keys: Set<string>): Record<string, unknown> {
+  return Object.fromEntries(
+    Object.entries(value).map(([key, item]) => [
+      key,
+      keys.has(key.toLowerCase()) ? "[REDACTED]" : item,
+    ]),
+  );
+}
+
+export function createStructuredLogger(options: StructuredLoggerOptions = {}): StructuredLogger {
+  const threshold = LEVELS[options.level ?? "info"];
+  const now = options.now ?? (() => new Date());
+  const sink = options.sink ?? ((_record, line) => console.log(line));
+  const redacted = new Set(
+    (options.redact ?? ["authorization", "cookie", "password", "secret", "token"]).map((key) =>
+      key.toLowerCase(),
+    ),
+  );
+  const base = { ...(options.attributes ?? {}) };
+  const logger = (attributes: Record<string, unknown>): StructuredLogger => {
+    const log = (level: LogLevel, message: string, values: Record<string, unknown> = {}) => {
+      if (LEVELS[level] < threshold) return;
+      const combined = scrub({ ...attributes, ...values }, redacted);
+      const record: LogRecord = {
+        timestamp: now().toISOString(),
+        level,
+        message,
+        service: options.service ?? "wrnexus",
+        ...(typeof combined.traceId === "string" ? { traceId: combined.traceId } : {}),
+        ...(typeof combined.spanId === "string" ? { spanId: combined.spanId } : {}),
+        ...(typeof combined.requestId === "string" ? { requestId: combined.requestId } : {}),
+        attributes: combined,
+      };
+      sink(record, JSON.stringify(record));
+    };
+    return {
+      log,
+      debug: (message, values) => log("debug", message, values),
+      info: (message, values) => log("info", message, values),
+      warn: (message, values) => log("warn", message, values),
+      error: (message, values) => log("error", message, values),
+      child: (values) => logger({ ...attributes, ...values }),
+    };
+  };
+  return logger(base);
+}