TypeError on cypress open tty.getWindowSize

Is this a Feature or Bug?

Bug

Current behavior:

On cypress open, some users are getting TypeError on new update to 3.0.0

TypeError: tty.getWindowSize is not a function
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\lib\reporters\base.js:120:13)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\lib\reporters\base.js:489:3)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\lib\reporters\index.js:3:31)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\lib\reporters\index.js:21:3)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\lib\mocha.js:13:17)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\lib\mocha.js:504:3)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\index.js:3:5)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\node_modules\mocha\index.js:5:3)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\lib\reporter.js:11:11)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\lib\reporter.js:402:4)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\lib\reporter.js:404:3)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\lib\project.js:49:14)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\lib\project.js:654:4)
at Object.<anonymous> (C:\Users\Ladder Digital\AppData\Local\Cypress\Cache\3.0.0\Cypress\resources\app\packages\server\lib\project.js:656:3)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anon

Desired behavior:

No TypeError 😃

Steps to reproduce:

.node_modules\.bin\cypress open

Versions

Cypress: 3.0.0 OSes observered: Windows 10 Pro, Windows 8.1, Windows 7

[jennifer-shehane]

Fixed in 3.0.1.

[brian-mann]

Okay I understand the root cause. When spawning a process in electron in Windows isTTY is always false as per these electron tests…

https://github.com/electron/electron/pull/7143/files#diff-772c67b73618ae46d1b7e8b22e1ec85cR240

What’s happening is that we are actually tricking / forcing the electron/node process to believe that windows is in fact a tty. This changed in 3.0 and it’s important because we want things like terminal windows + reporters to color text and think we are a tty.

Mocha is using an undocumented method on node to try to figure out the window size, and because we don’t monkey patch this it falls through to the second check - which apparently is using a method on tty that has never existed and is a bug in mocha.

To fix this we’ll need to polyfill the actual method in node in Windows which is…

function () { 
  return [this.columns, this.rows]
}

HOWEVER! this.columns and this.rows will be undefined in node so we have to polyfill those too! Lucky we use term-size and already have a lib wrapper around that so we can just use that…