base.js

import tty from 'node:tty';

// eslint-disable-next-line no-warning-comments
// TODO: Use a better method when it's added to Node.js (https://github.com/nodejs/node/pull/40240)
// Lots of optionals here to support Deno.
const hasColors = tty?.WriteStream?.prototype?.hasColors?.() ?? false;

const format = (open, close) => {
	if (!hasColors) {
		return input => input;
	}

	const openCode = `\u001B[${open}m`;
	const closeCode = `\u001B[${close}m`;

	return input => {
		const string = input + ''; // eslint-disable-line no-implicit-coercion -- This is faster.
		let index = string.indexOf(closeCode);

		if (index === -1) {
			// Note: Intentionally not using string interpolation for performance reasons.
			return openCode + string + closeCode;
		}

		// Handle nested colors.

		// We could have done this, but it's too slow (as of Node.js 22).
		// return openCode + string.replaceAll(closeCode, openCode) + closeCode;

		let result = openCode;
		let lastIndex = 0;

		while (index !== -1) {
			result += string.slice(lastIndex, index) + openCode;
			lastIndex = index + closeCode.length;
			index = string.indexOf(closeCode, lastIndex);
		}

		result += string.slice(lastIndex) + closeCode;

		return result;
	};
};

export const reset = format(0, 0);
export const bold = format(1, 22);
export const dim = format(2, 22);
export const italic = format(3, 23);
export const underline = format(4, 24);
export const overline = format(53, 55);
export const inverse = format(7, 27);
export const hidden = format(8, 28);
export const strikethrough = format(9, 29);

export const black = format(30, 39);
export const red = format(31, 39);
export const green = format(32, 39);
export const yellow = format(33, 39);
export const blue = format(34, 39);
export const magenta = format(35, 39);
export const cyan = format(36, 39);
export const white = format(37, 39);
export const gray = format(90, 39);

export const bgBlack = format(40, 49);
export const bgRed = format(41, 49);
export const bgGreen = format(42, 49);
export const bgYellow = format(43, 49);
export const bgBlue = format(44, 49);
export const bgMagenta = format(45, 49);
export const bgCyan = format(46, 49);
export const bgWhite = format(47, 49);
export const bgGray = format(100, 49);

export const redBright = format(91, 39);
export const greenBright = format(92, 39);
export const yellowBright = format(93, 39);
export const blueBright = format(94, 39);
export const magentaBright = format(95, 39);
export const cyanBright = format(96, 39);
export const whiteBright = format(97, 39);

export const bgRedBright = format(101, 49);
export const bgGreenBright = format(102, 49);
export const bgYellowBright = format(103, 49);
export const bgBlueBright = format(104, 49);
export const bgMagentaBright = format(105, 49);
export const bgCyanBright = format(106, 49);
export const bgWhiteBright = format(107, 49);