TypeScript Version: 2.7.1

Search Terms: infer, compare, equals

Code

type T = [number] | [number, number]; // now t.length has type 1|2 let t: T; if (t!.length === 0) { // compile error: Operator '===' cannot be applied to types '1' and '0' } if (t!.length > 100) { // no compile error } if (t!.length === 1 - 1) { // no compile error }

Expected behavior:
No compile errors on any of these. It's plain inconsistent and not useful.

Actual behavior:
Compile error on t === 0 but not on other comparisons

Playground Link:
See above

Related Issues: