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Syntax highlighting: generic type arguments are highly affected by whitespace and other irrelevant context

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
typescript
Domain
tooling

Research direction

Start with the TypeScript TextMate grammar files in this repository and reproduce the Playground example in VS Code using the Monokai Pro color scheme. Compare generic type arguments across the whitespace and surrounding-context variations shown in the issue. Done means the listed identifiers, angle brackets, parentheses, type arguments, and numeric arguments receive consistent highlighting.

Written by the indexing model from the issue text.

Description

bug help wanted
🔎 Search Terms

syntax highlighting generics

🕗 Version & Regression Information

This is the behavior in every version I tried, and I reviewed the FAQ for entries about syntax highlighting and generics.

⏯ Playground Link

https://www.typescriptlang.org/play?#code/CYUwxgNghgTiAEAzArgOzAFwJYHtXygCMwAeAQQBp4AhKgYQD4AKASgC540BrVHAd1QAoQWDwBnDAWIAmeAF4ppAIxVpVAMwMR4yUTDr5ikgA0qATSoAtLaNQTFAFkN6SggJAr3a9+sE2digCszsSubqbuFu6WfsK29nBiyBAYSiHKqhrMLHEBickYsgou7p5u3m6+2bl2kvkpBsWhpvAW8NasNQkgSSlOTaTuEW5RbjHV2rUEMDCGANruLirwavCarBSLoe4em27le5Xu2XsuLW0dLKfb+8MjhzFuJ4IAul2SOIQAVoYA3u71VIcJaZNYMeAbAE9ArSYE3XY7CpHJ6QtyA9Rw0jnKzPNHQvqYsLhQ6jMbHSEAX2EAHpqfAAHSMwQYACeAAcEMZDNxeAJmeyEGZuagePwhKyOe1haK+UA

💻 Code
declare function abc<A, B, C>(): unknown

const abc2 = abc<1, 2, 3>
const abc3 = abc<X, Y, Z>
const abc4 = abc<
	1,
	2,
	3
>
const abc5 = abc<
	X,
	Y,
	Z
>

const result1 = abc<1, 2, 3>()

const result2 = abc<
	1,
	2,
	3
>()

const result3 = abc<X, Y, Z>()

const result4 = abc<
	X,
	Y,
	Z
>()

const arr = [
	abc<1, 2, 3>(),
	abc<
		1,
		2,
		3
	>(),
	abc<X, Y, Z>(),
	abc<
		X,
		Y,
		Z
	>(),
]

const obj = {
	result1: abc<1, 2, 3> (),
	result2: abc<
		1,
		2,
		3
	>(),
	result3: abc<X, Y, Z>(),
	result4: abc<
		X,
		Y,
		Z
	>(),
}
🙁 Actual behavior

Declaring a function signature with generics seems to be pretty robust to changes in whitespace and surrounding context, but passing type arguments is extremely brittle.

This is the preceding code sample in VS Code with the Monokai Pro color scheme:

image

🙂 Expected behavior

Consistent syntax highlighting:

  • abc to be consistently green (3/16)
  • <> to be consistently gray (3/16)
  • () to be consistently gray (8/12)
  • X, Y, Z to be consistently blue (3/8)
  • 1, 2, 3 to be consistently purple (6/8)
Additional information about the issue

Original issue in monokai-pro-vscode

Dominant language
TypeScript
Stars
471
Forks
149
PR merge metrics
No merged PRs in 30d

Contributor guide

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First steps

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  4. Open a pull request that references the issue number.

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