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Generic syntax ambiguity is handled incorrectly #60874
Description
🔎 Search Terms
generic syntax ambiguity
🕗 Version & Regression Information
- I was unable to test this on prior versions because there is no online tooling for it
⏯ Playground Link
💻 Code
const a = 1, b = 2, c = 3, d = 4, e = 5;
console.log(a < b, (c > (d & e)));🙁 Actual behavior
This expression is not callable.
🙂 Expected behavior
true false
Additional information about the issue
While there might be some justification for why
const a = 1, b = 2, c = 3, d = 4, e = 5;
console.log(a < b, c > (d & e));doesn't work as it did in JS, in the provided example there isn't even any disambiguity.
Reacted by Rob Palmer
Activity
robpalme commentedon Dec 30, 2024
The general Relational Expression ambiguity is a long-standing known issue. But as you mention, this is a more specific case where there's no ambiguity given that
< b, (c >cannot be parsed as type arguments.Whilst the TypeScript parser deems
< b, (c >to be erasable types, most other mainstream parsers do not. These parsers correctly preserve the original JS semantics when attempting to parse as TS:magic-akari commentedon Nov 15, 2026
I’m working on a fix for this.