JS/TS semantic highlighting for keywords (readonly global vars)

[a-ejs]

TS Template added by @mjbvz

TypeScript Version: 4.1.2

Search Terms

• semantic highlighting
• constant
• readonly

---

vscode 1.52.0

Code:

undefined;
Infinity;
NaN;

Result:

Semantic highlighting recolors Infinity and NaN from constant.language to variable.

Expected:

All three identifiers should be colored identically.

[mjbvz]

Moving this upstream since the TS team is taking ownership of semantic highlighting

[9at8]

I did some digging and my initial thought was that it's there's either an issue on the vscode side, or the typescript server is not returning the correct token. (Probably these lines?)

I debugged the vscode typescript-language-features extension:

Looking at the tokenSpan (coming from the typescript server) seems to look ok (the first 3 classifications are all 2064 so the first three lines are the same type) and the return value also seems to match this expectation.

Now I think that the problem is somewhere in the typescript-language-features extension, but I am stuck. 🙈 Am I headed in the right direction? Any tips on what I should be looking at?

PS: After hitting continue, the test.ts file does produce the error reported in this issue.

[9at8]

Just wanted to follow up on this :)

cc @orta

[orta]

You'll want to look into classifier2020.ts in TypeScript, notably in this function:

TypeScript/src/services/classifier2020.ts

Line 54 in 4a10aee

function collectTokens(program: Program, sourceFile: SourceFile, span: TextSpan, collector: (node: Node, tokenType: number, tokenModifier: number) => void, cancellationToken: CancellationToken) {

Where you can check if the identifier is one of the known globals 👍🏻