test/parallel/test-tty-backwards-api.js

// Flags: --expose-internals
'use strict';
const common = require('../common');
const assert = require('assert');
const readline = require('readline');

const noop = () => {};
const { internalBinding } = require('internal/test/binding');
const TTY = internalBinding('tty_wrap').TTY = function() {};

TTY.prototype = {
  setBlocking: noop,
  getWindowSize: noop
};

const { WriteStream } = require('tty');

[
  'cursorTo',
  'moveCursor',
  'clearLine',
  'clearScreenDown',
].forEach((method) => {
  readline[method] = common.mustCall(function() {
    const lastArg = arguments[arguments.length - 1];

    if (typeof lastArg === 'function') {
      process.nextTick(lastArg);
    }

    return true;
  }, 2);
});

const writeStream = new WriteStream(1);

// Verify that the corresponding readline methods are called, that the return
// values are propagated, and any callbacks are invoked.
assert.strictEqual(writeStream.cursorTo(1, 2), true);
assert.strictEqual(writeStream.cursorTo(1, 2, common.mustCall()), true);
assert.strictEqual(writeStream.moveCursor(1, 2), true);
assert.strictEqual(writeStream.moveCursor(1, 2, common.mustCall()), true);
assert.strictEqual(writeStream.clearLine(1), true);
assert.strictEqual(writeStream.clearLine(1, common.mustCall()), true);
assert.strictEqual(writeStream.clearScreenDown(), true);
assert.strictEqual(writeStream.clearScreenDown(common.mustCall()), true);