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Comparison operators ("<", ">") incorrectly interpreted as type parameters

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
48/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
typescript
Domain
tooling

Research direction

Start with the TypeScript and JavaScript Grammar Extension and reproduce the reported snippet in VS Code using the syntax scopes shown in the issue. Trace how the comparison operators are classified in the grammar; done means < and > remain comparison operators while the surrounding type assertion and property access receive normal highlighting.

Written by the indexing model from the issue text.

Description

TS and JS Grammar Extension version: 0.0.55 / latest

Code

// Contrived because of simplification
let a = 7
let b = {}
if (a < (b as {c: number}).c || a > (b as {c: number}).c) {

}

If statement parsing:

if [keyword.control.conditional.ts, source.ts]
( [meta.brace.round.ts, source.ts]
a [entity.name.function.ts, meta.function-call.ts, source.ts]
< [punctuation.definition.typeparameters.begin.ts, meta.type.parameters.ts, source.ts]
( [meta.brace.round.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
b [entity.name.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
as [entity.name.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
{ [punctuation.definition.block.ts, meta.object.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
c [variable.object.property.ts, meta.definition.property.ts, meta.field.declaration.ts, meta.object.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
: [meta.type.annotation.ts, meta.field.declaration.ts, meta.object.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
number [support.type.primitive.ts, meta.type.annotation.ts, meta.field.declaration.ts, meta.object.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
} [punctuation.definition.block.ts, meta.object.type.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
) [meta.brace.round.ts, meta.type.paren.cover.ts, meta.type.parameters.ts, source.ts]
. [meta.type.parameters.ts, source.ts]
c [entity.name.type.ts, meta.type.parameters.ts, source.ts]
| [keyword.operator.type.ts, meta.type.parameters.ts, source.ts]
| [keyword.operator.type.ts, meta.type.parameters.ts, source.ts]
a [entity.name.type.ts, meta.type.parameters.ts, source.ts]
> [punctuation.definition.typeparameters.begin.ts, meta.type.parameters.ts, source.ts]

(rest is normal)

So like:
if ( a<type>(parameters).c ) {}

Example in vscode:
image

Actual code:
image

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

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