Variable "name" in VSCode editor(intelli-sense) is showing incorrect information

[preethidaran]

TS Template added by @mjbvz

TypeScript Version: 4.0.0-dev.20200708

Search Terms

• javascript
• lib.dom
• globals

---

• VSCode Version: 1.46.1
• OS Version: Windows 10

Steps to Reproduce:

1. Add the following javascript code

var name = "Hi";
console.log(name);
name = "Hello";
console.log(name);

2. Hover over(Mouseover) the variable "name" (in any of the console log statements given above).......picture attached.

3. Expected: During mouse/hover over, variable "name" on the console statement should display "name" as a variable.

   Actual: During mouse/hover over, variable "name" on the console statement is showing it as constant. (actually, it's not a constant). Because I'm able to modify the value of the variable "name" from "Hi" to "Hello". This explains "name" is implemented as a variable.

Does this issue occur when all extensions are disabled?: Yes

[mjbvz]

Duplicate of #31783. See that issue for details

@RyanCavanaugh This has been reported a few times now so I wonder if there's anything we can do. I suspect beginning JS users are most likely to hit this since:

• They are not using modules
• They are writing code in the global scope.
• They would not know about the lib.dom typings or how to fix the issue

[RyanCavanaugh]

@mjbvz open to suggestions here. Not sure what might do since there's really no way to tell if this file is intended for a DOM context or not

[mjbvz]

One old idea I had was an option that forces TS to treat each file as an implicit module (even if it does not use import or export): #14279. I believe that would also address this issue.

We could also be more pragmatic and just remove the name global from the dom typings. That seems to be the variable that people hit this problem with most often (and I suspect there is not much real world code that uses the name global)