Extends a Class will make losing and corrupted types in a child class. · Issue #42541 · microsoft/TypeScript · GitHub

When we add types on properties base class, if a child class extends this base class, we will lost types and get corrupted behavior. Actually is seem affected by keyof T, i not tested all others types, but this one make coruptions. From

Support override keyword on class methods · Issue #2000 · microsoft/ TypeScript · GitHub

type inferrence with override methods in child class · Issue #31470 · microsoft/TypeScript · GitHub

Support final classes (non-subclassable) · Issue #8306 · microsoft/ TypeScript · GitHub

Support override keyword on class methods · Issue #2000 · microsoft/ TypeScript · GitHub

Support final classes (non-subclassable) · Issue #8306 · microsoft/ TypeScript · GitHub

instanceof is broken when class extends Error type · Issue #13965 · microsoft/TypeScript · GitHub

typesVersions should not be affected by `types: ` · Issue #28304 · microsoft/TypeScript · GitHub

Support override keyword on class methods · Issue #2000 · microsoft/ TypeScript · GitHub

Getting recursive type errors with TS 4.3.2 when they don't happen with TS 4.2.4 · Issue #44281 · microsoft/TypeScript · GitHub

class MyArray extends Array broken in Typescript 2.1.5 · Issue #13720 · microsoft/TypeScript · GitHub

Error: Class incorrectly extends base class cannot assign type · Issue #2073 · microsoft/TypeScript · GitHub

Extends a Class will make losing and corrupted types in a child class. · Issue #42541 · microsoft/TypeScript · GitHub