tests/cases/compiler/recursiveBaseCheck3.ts(1,7): error TS2310: Type 'A' recursively references itself as a base type. tests/cases/compiler/recursiveBaseCheck3.ts(4,9): error TS2339: Property 'blah' does not exist on type 'C<{}>'. ==== tests/cases/compiler/recursiveBaseCheck3.ts (2 errors) ==== class A extends C { } ~ !!! error TS2310: Type 'A' recursively references itself as a base type. class C extends A { } (new C).blah; ~~~~ !!! error TS2339: Property 'blah' does not exist on type 'C<{}>'.