Function identifiers no longer receive semantic highlighting tokens

Bug Report

Function identifiers (including methods) don't appear to be receiving semantic highlighting tokens from the LSP as of TS 4.2.x.

This is important to me because I prefer the terser style of passing callbacks directly by identifier instead of always wrapping them in anonymous lambdas (e.g., myArray.filter(myPredicate) instead of myArray.filter(it => myPredicate(it))), but with the semantic colorization missing, it's much harder to recognize where this is happening when scanning code.

🔎 Search Terms

semantic highlight, highlighting, function, token

🕗 Version & Regression Information

• Semantic function tokens worked as expected in 4.1.5
• They appear to be missing in 4.2.4 (VS Code's version at time of writing)

💻 Code

CodeSnap with TS v4.0.7:

CodeSnap with TS v.4.2.4:

Textual representation for the sake of screen-readers and whatnot:

let result = [...newFiles];

const compareFileName: Comparator<INewFile|IDisplayFile> = (a, b) => a.FileName === b.FileName;
const isDisplayFile = (item: INewFile|IDisplayFile): item is IDisplayFile => !!item.ExternalId;

const currentFiles = this._displayFiles$.value ?? [];
const dupes = intersectionWith(compareFileName, newFiles, currentFiles);

if (!dupes.length) {
	return result;
}

// Find the sets of current files and new uploads that are unique.
const [currentUniques, newUniques] = flow(
	xorWith(compareFileName),
	partition(isDisplayFile),
)(currentFiles, newFiles);

🙁 Actual behavior

In the newer snap, notice that references to compareFileName and isDisplayFile are colored as ordinary variables after their declarations. Invoking VS Code's "Inspect Editor Tokens and Scopes" command on those tokens indicates that they're falling back to their TextMate scopes instead of using the semantic information.

🙂 Expected behavior

In the older snap, all references to the function names are colored as functions, making it easier to spot which arguments are callbacks when scanning the code. Invoking the "Inspect..." command on these shows that they're marked with the function semantic token type, with readonly and local modifiers.