tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithStringIndexer3.ts(7,8): error TS2304: Cannot find name 'A'. tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithStringIndexer3.ts(20,9): error TS2322: Type '{ [x: string]: string; }' is not assignable to type 'A'. Index signatures are incompatible. Type 'string' is not assignable to type 'T'. tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithStringIndexer3.ts(21,9): error TS2322: Type 'A' is not assignable to type '{ [x: string]: string; }'. Index signatures are incompatible. Type 'T' is not assignable to type 'string'. ==== tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithStringIndexer3.ts (3 errors) ==== // Derived type indexer must be subtype of base type indexer interface Base { foo: string; } interface Derived extends Base { bar: string; } interface Derived2 extends Derived { baz: string; } var a: A; ~ !!! error TS2304: Cannot find name 'A'. var b1: { [x: string]: string; } a = b1; // error b1 = a; // error module Generics { class A { [x: string]: T; } function foo() { var a: A; var b: { [x: string]: string; } a = b; // error ~ !!! error TS2322: Type '{ [x: string]: string; }' is not assignable to type 'A'. !!! error TS2322: Index signatures are incompatible. !!! error TS2322: Type 'string' is not assignable to type 'T'. b = a; // error ~ !!! error TS2322: Type 'A' is not assignable to type '{ [x: string]: string; }'. !!! error TS2322: Index signatures are incompatible. !!! error TS2322: Type 'T' is not assignable to type 'string'. } }