[socket.io.js] document.createElement is not a function

From @warren-bank on September 21, 2016 23:48

(edit: you can jump ahead to my final comment.. to see the very minor code patch I would suggest be applied, which would fix this issue)

I was super pleased to discover that the karma test runner could be used in conjunction with the interactive debugger:
tns test android --debug-brk

However, I did want to raise one small issue..

The application crashed because of an uncaught exception. You can look at "stackTrace" or "nativeException" for more detailed information about the exception.
com.tns.NativeScriptException: 
Calling js method run failed

TypeError: document.createElement is not a function
File: "/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js, line: 201, column: 25

StackTrace: 
    Frame: function:'JSONPPolling.doPoll', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 1085, column: 25
    Frame: function:'Polling.poll', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 1740, column: 8
    Frame: function:'Polling.doOpen', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 1684, column: 8
    Frame: function:'Transport.open', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 827, column: 10
    Frame: function:'Socket.open', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 248, column: 13
    Frame: function:'Socket', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 129, column: 8
    Frame: function:'Socket', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 55, column: 41
    Frame: function:'Manager.open.Manager.connect', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 4549, column: 17
    Frame: function:'', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/nativescript-unit-test-runner/socket.io.js', line: 4859, column: 12
    Frame: function:'ZoneDelegate.invokeTask', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js', line: 323, column: 38
    Frame: function:'Zone.runTask', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js', line: 223, column: 48
    Frame: function:'ZoneTask.invoke', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js', line: 391, column: 34
    Frame: function:'ZoneDelegate.invoke', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js', line: 290, column: 29
    Frame: function:'Zone.runGuarded', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js', line: 197, column: 48
    Frame: function:'', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/zone.js/dist/zone-node.js', line: 173, column: 30
    Frame: function:'java.lang.Runnable.run', file:'/data/data/org.nativescript.ExampleProject/files/app/tns_modules/timer/timer.js', line: 17, column: 13

the file nativescript-unit-test-runner/socket.io.js is pretty much littered with references to the DOM, and attempts to perform DOM updates.

in particular:

• JSONPPolling.prototype.doPoll
• JSONPPolling.prototype.doWrite
• useColors
• localstorage
• various references to: navigator.userAgent

I haven't done any digging into this.
I'm not aware of the low-level details of precisely how socket.io is used by the test runner,
or why the debugger would trigger additional polling,
or why this error didn't occur while either:

• debugging "app/main.js"
• unit testing "app/tests/*.js"

and only occurs while debugging these unit tests.

Maybe this is nothing more than pilot error (on my part)..
I wouldn't rule it out, though I don't think that I've done anything wrong.

In any case, I just wanted to share my observations..
in case somebody who knows the code and how things are glued together..
might read this and mutter: "oh shoot, yep.. easy fix"

Copied from original issue: NativeScript/nativescript-unit-test-runner#17

使用 tns test android --debug-brk 重現失敗，然後檢查 nativescript-unit-test-runner/socket.io.js，尤其是 JSONPPolling.prototype.doPoll、doWrite、useColors 和 localstorage。將偵錯器路徑與列出的堆疊追蹤進行比較，並判斷它為什麼會到達 DOM API。完成標準是偵錯器可以在不出現 document.createElement 例外的情況下執行這些單元測試。