Clear lines

[zmnv]

The same file, but with the clear lines.

const os = require('os');
const readline = require('readline');
const keypress = require('keypress');

const defaultHelpMessage =
    'Type a hotkey or use Down/Up arrows then Enter to choose an item.';

/**
 * Displays a menu of items in the console and asynchronously waits for the user to select an item.
 *
 * @param {any} items Array of menu items, where each item is an object that includes a title
 * property and optional hotkey property. (Items may include additional user-defined properties.)
 * @param {any} options Dictionary of options for the menu:
 *   - header {string}: Header text for the menu.
 *   - border {boolean}: True to draw a border around the menu.
 *   - pageSize {integer}: Max number of items to show at a time. Additional items cause the menu
 *     to be scrollable.
 *   - helpMessage {string}: Message text to show under the menu.
 * @returns A promise that resolves to the chosen item, or to null if the menu was cancelled.
 */
function menu(items, options) {
    if (!items || !Array.isArray(items) || items.length < 1) {
        throw new TypeError('A nonempty items array is required.');
    }
    options = options || {};

    var count = items.length;
    var selectedIndex = items.findIndex(item => item.selected);
    if (selectedIndex < 0) {
        selectedIndex = 0;
        while (selectedIndex < count && items[selectedIndex].separator) selectedIndex++;
    }

    var scrollOffset = 0;
    printMenu(items, options, selectedIndex, scrollOffset);

    return new Promise((resolve, reject) => {
        process.stdin.setRawMode(true);
        process.stdin.resume();
        keypress(process.stdin);

        var handleMenuKeypress = (ch, key) => {
            var selection = null;
            if (isEnter(key)) {
                selection = items[selectedIndex];
            } else if (ch) {
                selection = items.find(item => item.hotkey && item.hotkey === ch) ||
                    items.find(item => item.hotkey &&
                        item.hotkey.toLowerCase() === ch.toLowerCase());
            }

            var newIndex = null;
            if (selection || isCancelCommand(key)) {
                process.stdin.removeListener('keypress', handleMenuKeypress);
                process.stdin.setRawMode(false);
                resetCursor(options, selectedIndex, scrollOffset);
                readline.clearScreenDown(process.stdout);
                process.stdin.pause();
                resolve(selection);
            } else if (isUpCommand(key) && selectedIndex > 0) {
                newIndex = selectedIndex - 1;
                while (newIndex >= 0 && items[newIndex].separator) newIndex--;
            } else if (isDownCommand(key) && selectedIndex < count - 1) {
                newIndex = selectedIndex + 1;
                while (newIndex < count && items[newIndex].separator) newIndex++;
            } else if (isPageUpCommand(key) && selectedIndex > 0) {
                newIndex = (options.pageSize ? Math.max(0, selectedIndex - options.pageSize) : 0);
                while (newIndex < count && items[newIndex].separator) newIndex++;
            } else if (isPageDownCommand(key) && selectedIndex < count - 1) {
                newIndex = (options.pageSize
                    ? Math.min(count - 1, selectedIndex + options.pageSize) : count - 1);
                while (newIndex >= 0 && items[newIndex].separator) newIndex--;
            } else if (isGoToFirstCommand(key) && selectedIndex > 0) {
                newIndex = 0;
                while (newIndex < count && items[newIndex].separator) newIndex++;
            } else if (isGoToLastCommand(key) && selectedIndex < count - 1) {
                newIndex = count - 1;
                while (newIndex >= 0 && items[newIndex].separator) newIndex--;
            }

            if (newIndex !== null && newIndex >= 0 && newIndex < count) {
                resetCursor(options, selectedIndex, scrollOffset);

                selectedIndex = newIndex;

                // Adjust the scroll offset when the selection moves off the page.
                if (selectedIndex < scrollOffset) {
                    scrollOffset = (isPageUpCommand(key)
                        ? Math.max(0, scrollOffset - options.pageSize) : selectedIndex);
                } else if (options.pageSize && selectedIndex >= scrollOffset + options.pageSize) {
                    scrollOffset = (isPageDownCommand(key)
                        ? Math.min(count - options.pageSize, scrollOffset + options.pageSize)
                        : selectedIndex - options.pageSize + 1);
                }

                printMenu(items, options, selectedIndex, scrollOffset);
            }
        };

        process.stdin.addListener('keypress', handleMenuKeypress);
    });
}

function isEnter(key) { return key && (key.name === 'enter' || key.name === 'return'); }
function isUpCommand(key) { return key && key.name === 'up'; }
function isDownCommand(key) { return key && key.name === 'down'; }
function isPageUpCommand(key) { return key && key.name === 'pageup'; }
function isPageDownCommand(key) { return key && key.name === 'pagedown'; }
function isGoToFirstCommand(key) { return key && key.name === 'home'; }
function isGoToLastCommand(key) { return key && key.name === 'end'; }
function isCancelCommand(key) {
    return key && ((key.ctrl && key.name == 'c') || key.name === 'escape');
}

function resetCursor(options, selectedIndex, scrollOffset) {
    readline.moveCursor(process.stdout, -3,
        - (options.header ? 1 : 0)
        - (options.border ? (options.header ? 2 : 1) : 0)
        - selectedIndex + scrollOffset);
}

function printMenu(items, options, selectedIndex, scrollOffset) {
    var repeat = (s, n) => {
        return Array(n + 1).join(s);
    };

    var width = 0;
    for (var i = 0; i < items.length; i++) {
        if (items[i].title && 4 + items[i].title.length > width) {
            width = 4 + items[i].title.length;
        }
    }

    var prefix = (options.border ? '│' : '');
    var suffix = (options.border ? ' │' : '');

    if (options.header && options.header.length > width) {
        width = options.header.length;
    }

    if (options.border) {
        if (!options.header && options.pageSize && scrollOffset > 0) {
            process.stdout.write('.──/\\' + repeat('─', width - 2) + '?' + os.EOL);
        } else {
            process.stdout.write('┌' + repeat('─', width + 2) + '┐' + os.EOL);
        }
    }

    if (options.header) {
        process.stdout.write(prefix + (options.border ? ' ' : '') + options.header +
            repeat(' ', width - options.header.length) + suffix + os.EOL);
        if (options.border) {
            if (options.pageSize && scrollOffset > 0) {
                process.stdout.write('+──/\\' + repeat('─', width - 2) + '+' + os.EOL);
            } else {
                process.stdout.write('├' + repeat('─', width + 2) + '┤' + os.EOL);
            }
        }
    }

    var scrollEnd = options.pageSize
        ? Math.min(items.length, scrollOffset + options.pageSize)
        : items.length;
    for (var i = scrollOffset; i < scrollEnd; i++) {
        if (items[i].separator) {
            process.stdout.write(prefix + ' ' + repeat(' ', width) + suffix + os.EOL);
        } else {
            var hotkey = items[i].hotkey || '*';
            var title = items[i].title || '';
            var label = (i === selectedIndex
                ? '[' + hotkey + ']' : ' ' + hotkey + ')');
            process.stdout.write(prefix + ' ' + label + ' ' + title +
                repeat(' ', width - title.length - 4) + suffix + os.EOL);
        }
    }

    if (options.border) {
        if (options.pageSize && scrollEnd < items.length) {
            process.stdout.write('└──\\/' + repeat('─', width - 2) + '┘' + os.EOL);
        } else {
            process.stdout.write('└' + repeat('─', width + 2) + '┘' + os.EOL);
        }
    }

    process.stdout.write(options.helpMessage || defaultHelpMessage);
    readline.moveCursor(process.stdout,
        -(options.helpMessage || defaultHelpMessage).length + prefix.length + 2,
        -(options.border ? 1 : 0) - (scrollEnd - scrollOffset) + selectedIndex - scrollOffset);
}

module.exports = menu;

[ackvf]

Hey, cool. I have also added suport for this in my fork, as well as several other designs and support for custom table designs!

These and many more, currently there is 27 designs, check it out
https://github.com/ackvf/console-menu/blob/master/src/tablesDesigns.ts

/----------------------------------------------------------------------------------------
┏━━━━━┳━━━━━┓      +-----+-----+      ═════════════      ╒═════╤═════╕      ╔═════╦═════╗
┃[] []┃[] []┃      |[] []|[] []|       [] [] [] []       │[] []│[] []│      ║[] []║[] []║
┣━━━━━╋━━━━━┪      +-----+-----+      ═════════════      ╞═════╪═════╡      ╠═════╬═════╣
┃[] []┃[] []┃      |[] []|[] []|       [] [] [] []       │[] []│[] []│      ║[] []║[] []║
┗━━━━━┻━━━━━┛      +-----+-----+      ═════════════      ╘═════╧═════╛      ╚═════╩═════╝
/----------------------------------------------------------------------------------------
┌─────┬─────┐                         ┌           ┐      ┌     ┬     ┐       ───────────
│[] []│[] []│       [] [] [] []        [] [] [] []        [] [] [] []        [] [] [] []
├─────┼─────┤                                            ├     ┼     ┤       ───────────
│[] []│[] []│       [] [] [] []        [] [] [] []        [] [] [] []        [] [] [] []
└─────┴─────┘                         └           ┘      └     ┴     ┘       ───────────
/----------------------------------------------------------------------------------------
                                      ┌───────────┐                          ───────────
│[] []│[] []│       [] []│[] []       │[] [] [] []│      │[] [] [] []        [] [] [] []
│     │     │       ─────┼─────       │           │      │
│[] []│[] []│       [] []│[] []       │[] [] [] []│      │[] [] [] []        [] [] [] []
                                      └───────────┘                          ───────────
/----------------------------------------------------------------------------------------