swc/crates/swc_ecma_parser/tests/tsc/mixinAbstractClasses.2.ts

// @target: esnext
// @declaration: true

interface Mixin {
    mixinMethod(): void;
}

function Mixin<TBaseClass extends abstract new (...args: any) => any>(baseClass: TBaseClass): TBaseClass & (abstract new (...args: any) => Mixin) {
    // error expected: A mixin class that extends from a type variable containing an abstract construct signature must also be declared 'abstract'.
    class MixinClass extends baseClass implements Mixin {
        mixinMethod() {
        }
    }
    return MixinClass;
}

abstract class AbstractBase {
    abstract abstractBaseMethod(): void;
}

const MixedBase = Mixin(AbstractBase);

// error expected: Non-abstract class 'DerivedFromAbstract' does not implement inherited abstract member 'abstractBaseMethod' from class 'AbstractBase & Mixin'.
class DerivedFromAbstract extends MixedBase {
}

// error expected: Cannot create an instance of an abstract class.
new MixedBase();