CustomConsole

/**
 * Function type for formatting console output messages
 * @param type - The type of log message
 * @param message - The message to format
 * @returns Formatted message string
 */
type Formatter = (type: LogType, message: LogMessage) => string;

/**
 * Console implementation that outputs to custom streams with optional formatting
 * Extends Node.js Console with custom stream and formatting capabilities
 */
class CustomConsole extends Console {
  /**
   * Creates a new CustomConsole instance
   * @param stdout - WriteStream for standard output
   * @param stderr - WriteStream for error output
   * @param formatBuffer - Optional formatter function for message processing
   */
  constructor(
    stdout: WriteStream,
    stderr: WriteStream,
    formatBuffer?: Formatter
  );
  
  /** Reference to the Node.js Console constructor */
  Console: typeof Console;
  
  /** Always returns undefined (no buffering in CustomConsole) */
  getBuffer(): undefined;
}

import { CustomConsole } from "@jest/console";
import type { WriteStream } from "tty";

// Basic usage with process streams
const console = new CustomConsole(process.stdout, process.stderr);
console.log("This goes to stdout");
console.error("This goes to stderr");

// With custom formatter
const formattedConsole = new CustomConsole(
  process.stdout,
  process.stderr,
  (type, message) => `[${type.toUpperCase()}] ${new Date().toISOString()}: ${message}`
);

formattedConsole.log("Hello, World!");
// Output: [LOG] 2023-01-01T12:00:00.000Z: Hello, World!

// With custom streams
import { Writable } from "stream";

let output = "";
const customStream = new Writable({
  write(chunk, encoding, callback) {
    output += chunk.toString();
    callback();
  }
}) as WriteStream;

const streamConsole = new CustomConsole(customStream, customStream);
streamConsole.log("Captured output");
console.log(output); // "Captured output\n"

/**
 * Log a message to stdout
 * @param firstArg - Primary message or data to log
 * @param args - Additional arguments to format and log
 */
log(firstArg: unknown, ...args: Array<unknown>): void;

/**
 * Log an informational message to stdout
 * @param firstArg - Primary message or data to log
 * @param args - Additional arguments to format and log
 */
info(firstArg: unknown, ...args: Array<unknown>): void;

/**
 * Log a debug message to stdout
 * @param firstArg - Primary message or data to log
 * @param args - Additional arguments to format and log
 */
debug(firstArg: unknown, ...args: Array<unknown>): void;

/**
 * Log a warning message to stderr
 * @param firstArg - Primary message or data to log
 * @param args - Additional arguments to format and log
 */
warn(firstArg: unknown, ...args: Array<unknown>): void;

/**
 * Log an error message to stderr
 * @param firstArg - Primary message or data to log
 * @param args - Additional arguments to format and log
 */
error(firstArg: unknown, ...args: Array<unknown>): void;

/**
 * Assert that a value is truthy, logging assertion failures to stderr
 * @param value - Value to test for truthiness
 * @param message - Optional message or Error object for assertion failure
 */
assert(value: unknown, message?: string | Error): asserts value;

/**
 * Log an object inspection to stdout
 * @param firstArg - Object to inspect
 * @param options - Optional inspection options from Node.js util.inspect
 */
dir(firstArg: unknown, options?: InspectOptions): void;

/**
 * Log XML-style object representation to stdout
 * @param firstArg - Primary object to log
 * @param args - Additional arguments to format and log
 */
dirxml(firstArg: unknown, ...args: Array<unknown>): void;

/**
 * Start a new console group with optional title, increasing indentation depth
 * @param title - Optional group title
 * @param args - Additional arguments to format in the title
 */
group(title?: string, ...args: Array<unknown>): void;

/**
 * Start a new collapsed console group with optional title
 * @param title - Optional group title
 * @param args - Additional arguments to format in the title
 */
groupCollapsed(title?: string, ...args: Array<unknown>): void;

/**
 * End the current console group, decreasing indentation depth
 */
groupEnd(): void;

/**
 * Increment and log a counter for the given label to stdout
 * @param label - Counter label, defaults to 'default'
 */
count(label?: string): void;

/**
 * Reset a counter for the given label to zero
 * @param label - Counter label to reset, defaults to 'default'
 */
countReset(label?: string): void;

/**
 * Start a timer with the given label
 * @param label - Timer label, defaults to 'default'
 */
time(label?: string): void;

/**
 * End a timer and log the elapsed time to stdout
 * @param label - Timer label to end, defaults to 'default'
 */
timeEnd(label?: string): void;

/**
 * Log the current elapsed time for a running timer to stdout
 * @param label - Timer label to check, defaults to 'default'
 * @param data - Additional data to log with the time
 */
timeLog(label?: string, ...data: Array<unknown>): void;