common.d.ts

export declare enum LogLevel {
    NONE = 1,
    ERROR = 2,
    WARN = 3,
    INFO = 4,
    DEBUG = 5
}
export declare enum LogFormat {
    FLAT = 1,
    PRETTY = 2,
    STRUCT = 3
}
export type LoggerAttributes = Record<string, string | number | undefined>;
/**
 * Signature of a Formatter function.
 * @param loggerConfig configuration of Logger instance
 * @param globalConfig global configuration
 * @param level logging level
 * @param message text to log
 * @param params A list of JavaScript objects to output.
 * @return array to pass to a console function
 */
export type FormatterFn = (loggerConfig: LoggerConfig, globalConfig: LoggerConfig, level: LogLevel, message: string, params: any[]) => any[];
/**
 * Configuration of a Logger.
 * See individual properties for details.
 * The default behavior of some vary based on runtime environment.
 * Some properties may be initialized via environment variables.
 * Configuration for all loggers may be set via the Logger.initialize(config) function.
 * Overrides for individual Loggers may be given in the constructor.
 */
export interface LoggerConfig {
    /**
     * Source module of the logger - prepended to each line.
     * Source file name or class name are good choices, but can be any label.
     */
    module: string;
    /**
     * Enabled logging level.
     * May be initialized via LOG_LEVEL environment variable.
     */
    level: LogLevel;
    /** Any additional context attributes to include with _structured_ format (only). */
    attributes?: LoggerAttributes;
    /**
     * Callback on every output to get real-time attributes.
     * With FLAT and PRETTY log formats, only the values (not keys) are output.
     */
    attributesCallback?: () => LoggerAttributes;
    /**
     * Include the level in log output?
     * Defaults to true if not streaming to CloudWatch;
     * always included with _structured_ format.
     */
    outputLevels: boolean;
    /**
     * Include timestamps in log output?
     * Defaults to false if streaming to CloudWatch (CloudWatch provides timestamps.),
     * true otherwise; always included with _structured_ format.
     * May override by setting the LOG_TIMESTAMPS environment variable to 'true' or 'false'.
     */
    logTimestamps: boolean;
    /**
     * Output format to use.
     * Defaults to FLAT if streaming to CloudWatch, PRETTY otherwise.
     * (Best to let CloudWatch provide its own pretty formatting.)
     * May initialize by setting the LOG_FORMAT environment variable to
     * "FLAT", "PRETTY", or "STRUCT".
     */
    format: LogFormat;
    /**
     * Function use to format output. Set based on format property, but may
     * be programmatically set instead.
     */
    formatter: FormatterFn;
}