React.createElement intellisense

[mjbvz]

From @czb on July 14, 2017 13:43

• VSCode Version: Code 1.14.1 (2648980a697a4c8fb5777dcfb2ab110cec8a2f58, 2017-07-13T19:18:47.188Z)
• OS Version: Windows_NT ia32 10.0.15063
• Extensions:

Extension	Author (truncated)	Version
vscodeZoom	chr	0.0.1

---

Steps to Reproduce:

1. Install @types/react
2. Create a ts file and paste:

import * as React from 'react'

interface Props { test: string }

class El extends React.Component<Props, any> { }

React.createElement(El, { test })

3. The intellisense of test in the last line is broken:
   a. When I start typing test the intellisense is NOT showing test
   b. When I finish typing test the intellisense suddenly finds and properly shows test (too late though)
   c. If I completely erase test from the last line, I get Property 'test' is missing in type '{}'. error as expected.

I guess the problem is that the intellisense for the second parameter of createElement is be based on the type of the first parameter.

EDIT: It is not React specific. The same issue also appears when using Mithril and other libraries.

Reproduces without extensions: Yes

Copied from original issue: microsoft/vscode#30709

[mjbvz]

From @czb on July 14, 2017 19:3

The same issue is discussed also here:

MithrilJS/mithril.d.ts#23

[oldrich-s]

Quite interestingly if interface Props { test: string } is changed to interface Props { test?: string }, the intellisense works just fine.

[mhegazy]

The completion list needs overload resolution to work first to be able to provide completions. and in this case overload resolution did not succeed. issue tracked by #8005