testem/lib/reporters/dev/patchcharm.js

Test'em 'scripts! Javascript Unit testing made easy.

/*

patchcharm.js
=============

A patch to charm to add text scrolling capability
and also a fix to `erase()`.

*/
'use strict';

const charm = require('charm');
const Charm = charm.Charm;

function encode(xs) {
  function bytes(s) {
    if (typeof s === 'string') {
      return s.split('').map(ord);
    } else if (Array.isArray(s)) {
      return s.reduce((acc, c) => acc.concat(bytes(c)), []);
    }
  }

  return new Buffer([0x1b].concat(bytes(xs)));
}

function ord(c) {
  return c.charCodeAt(0);
}

Charm.prototype.erase = function(s) {
  if (s === 'end' || s === '$') {
    this.write(encode('[K'));
  } else if (s === 'start' || s === '^') {
    this.write(encode('[1K'));
  } else if (s === 'line') {
    this.write(encode('[2K'));
  } else if (s === 'down') {
    this.write(encode('[J'));
  } else if (s === 'up') {
    this.write(encode('[1J'));
  } else if (s === 'screen') {
    this.write(encode('[2J'));
  } else {
    this.emit('error', new Error('Unknown erase type: ' + s));
  }
  return this;
};

Charm.prototype.enableScroll = function() {
  if (arguments.length === 0 || arguments[0] === 'screen') {
    this.write(encode('[r'));
  } else {
    let start = arguments[0];
    let end = arguments[1];
    this.write(encode('[' + start + ';' + end + 'r'));
  }
  return this;
};

Charm.prototype.scrollUp = function() {
  this.write(encode('M'));
};

Charm.prototype.scrollDown = function() {
  this.write(encode('D'));
};