import {
ENV_PHOENIX_LOG_LEVEL,
getStrFromEnvironment,
} from "@arizeai/phoenix-config";
export type LogLevel = "debug" | "info" | "warn" | "error" | "silent";
export type Logger = {
info: (message: string) => void;
warn: (message: string) => void;
error: (message: string) => void;
log: (message: string) => void;
debug: (message: string) => void;
table: (data: unknown) => void;
};
/**
* A logger that does nothing
*/
export const noopLogger = {
info: () => undefined,
warn: () => undefined,
error: () => undefined,
log: () => undefined,
debug: () => undefined,
table: () => undefined,
} satisfies Logger;
const VALID_LOG_LEVELS: readonly LogLevel[] = [
"debug",
"info",
"warn",
"error",
"silent",
];
function isLogLevel(value: string): value is LogLevel {
return VALID_LOG_LEVELS.includes(value as LogLevel);
}
function getLogLevelFromEnvironment(): LogLevel {
const value = getStrFromEnvironment(ENV_PHOENIX_LOG_LEVEL);
if (value && isLogLevel(value)) {
return value;
}
return "info";
}
/**
* Creates a logger with the given log level, optionally wrapping a custom logger.
* If no level is provided, reads PHOENIX_LOG_LEVEL from the environment, defaulting to "info".
* If a custom logger is provided, it is used as the underlying output target instead of console.
*
* Log level hierarchy (lowest to highest): debug < info < warn < error < silent
* Messages below the configured level are suppressed.
*
* @example
* const logger = createLogger(); // uses PHOENIX_LOG_LEVEL env var, defaults to "info"
* const logger = createLogger({ level: "debug" }); // show all messages including progress
* const logger = createLogger({ level: "silent" }); // suppress all output
* const logger = createLogger({ logger: myWinstonLogger }); // wrap a custom logger
* const logger = createLogger({ level: "warn", logger: myWinstonLogger }); // custom + level filter
*/
export function createLogger({
level,
logger,
}: { level?: LogLevel; logger?: Logger } = {}): Logger {
const resolvedLevel = level ?? getLogLevelFromEnvironment();
const levelIndex = VALID_LOG_LEVELS.indexOf(resolvedLevel);
const shouldLog = (l: LogLevel) => VALID_LOG_LEVELS.indexOf(l) >= levelIndex;
const base = logger ?? console;
return {
debug: shouldLog("debug") ? (msg) => base.debug(msg) : () => undefined,
info: shouldLog("info") ? (msg) => base.info(msg) : () => undefined,
warn: shouldLog("warn") ? (msg) => base.warn(msg) : () => undefined,
error: shouldLog("error") ? (msg) => base.error(msg) : () => undefined,
log: shouldLog("info") ? (msg) => base.log(msg) : () => undefined,
table: shouldLog("info") ? (data) => base.table(data) : () => undefined,
};
}
