TS6133: 'T' is declared but its value is never read

[yortus]

TypeScript Version: 2.8.0-dev.20180213

Search Terms:

• TS6133

Code

interface A<T> { T: T } // ERROR
//         ^^^ TS6133: 'T' is declared but its value is never read.

type B<T> = { T: T };   // OK

Expected behavior:
No errors.

Actual behavior:
TSC thinks the generic type T is unused in interface A, but it is used. Meanwhile the equivalent type B gets it right.

[ghost]

It looks like this actually does work in [email protected] -- was broken in [email protected] though.

[yortus]

@Andy-MS I'm definitely repro'ing this in typescript@next. Can you take another look please?

[ghost]

Oh, sorry, this was changed to --noUnusedParameters instead of --noUnusedLocals (#21167) so the error went away for me.