import type { LogEntry } from "./config.js";
/**
 * In-memory sink for testing purposes.
 * Captures all log entries in an array that can be inspected in tests.
 *
 * **Note:** This is primarily intended for testing SDK integrations.
 * Most applications should use the default console sink.
 *
 * @example
 * ```ts
 * import { InMemorySink, setGlobalLoggerConfig, createLogger } from "@alchemy/common";
 *
 * // In tests
 * const sink = new InMemorySink();
 *
 * setGlobalLoggerConfig({
 *   sinks: [sink.sink]
 * });
 *
 * const logger = createLogger({
 *   package: "@alchemy/aa-infra",
 *   version: "1.0.0",
 *   namespace: "aa-infra"
 * });
 *
 * logger.info("test message");
 *
 * // Inspect captured logs
 * expect(sink.count).toBe(1);
 * expect(sink.latest()?.message).toBe("test message");
 * ```
 */
export declare class InMemorySink {
    /**
     * Array of captured log entries
     */
    entries: LogEntry[];
    /**
     * Creates a new InMemorySink instance.
     * Binds the sink method to the instance for use as a callback.
     */
    constructor();
    /**
     * The sink function to pass to setGlobalLoggerConfig.
     * Captures log entries into the internal array.
     *
     * @param {LogEntry} entry - The log entry to capture
     * @returns {void}
     */
    sink(entry: LogEntry): void;
    /**
     * Clear all captured entries
     *
     * @returns {void}
     */
    clear(): void;
    /**
     * Get entries filtered by log level
     *
     * @param {number} level - The log level to filter by (LogLevel.ERROR, LogLevel.INFO, etc.)
     * @returns {LogEntry[]} Array of log entries matching the specified level
     */
    getByLevel(level: number): LogEntry[];
    /**
     * Get entries filtered by namespace
     *
     * @param {string} namespace - The namespace to filter by (e.g., "aa-infra", "wallet-apis")
     * @returns {LogEntry[]} Array of log entries matching the specified namespace
     */
    getByNamespace(namespace: string): LogEntry[];
    /**
     * Get entries filtered by message substring
     *
     * @param {string} substring - The substring to search for in log messages
     * @returns {LogEntry[]} Array of log entries containing the substring in their message
     */
    getByMessage(substring: string): LogEntry[];
    /**
     * Get the most recent log entry
     *
     * @returns {LogEntry | undefined} The latest log entry, or undefined if no entries have been captured
     */
    latest(): LogEntry | undefined;
    /**
     * Get the number of captured entries
     *
     * @returns {number} The total count of captured log entries
     */
    get count(): number;
}