class Type {
  method(callback) {
    Zone.root.run(callback, null, ['type']);
    return 'Type';
  }
}
class OverrideType extends Type {
  method(callback) {
    Zone.root.run(callback, null, ['override']);
    return 'Override';
  }
}
class Dummy extends Type {
}
function patchType(t) {
  return patchMethod(t.prototype, 'method', (delegate) => {
    console.log('patched');
    return function(self, args) {
      args[0] = Zone.current.wrap(args[0]);
      return delegate.apply(self, args);
    };
  });
}
const cb = (arg) => {
  console.log(`${arg} ${Zone.current.name}`);
};
const typeInstance = new Type();
const overrideInstance= new OverrideType();
const dummyInstance= new Dummy();
const zone = Zone.current.fork({name: 'patch'});

patchType(Type); // outputs 'patched'. Returns the unpatched Type.prototype.method
patchType(Dummy); // no output as method is just inherited. Returns the unpatched Type.prototype.method
const nativeOverride = patchType(OverrideType); // no output as it checks for proto[__symbol__('method')], which is inherited, instead of checking for proto.hasOwnProperty(__symbol__('method')). Returns the unpatched Type.prototype.method instead of OverrideType.prototype.method
zone.run(() => {
  typeInstance.method(cb); // 'type patch'
  dummyInstance.method(cb); // 'type patch'
  overrideInstance.method(cb); // 'override <root>'
  nativeOverride.apply(overrideInstance, [cb]); // 'type <root>'
});

const nativeOverride = patchType(OverrideType); // outputs 'patched' because the parent class hasn't been patched so it does not inherit proto[__symbol__('method')] yet. Returns the unpatched OverrideType.prototype.method
patchType(Type); // outputs 'patched'. Returns the unpatched Type.prototype.method
patchType(Dummy); // no output. Returns the unpatched Type.prototype.method
zone.run(() => {
  typeInstance.method(cb); // 'type patch'
  dummyInstance.method(cb); // 'type patch'
  overrideInstance.method(cb); // 'override patch'
  nativeOverride.apply(overrideInstance, [cb]); // 'override <root>'
});

patchType(Type); // outputs 'patched'. Returns the unpatched Type.prototype.method
patchType(Dummy); // no output as method is just inherited. Returns the unpatched Type.prototype.method
const nativeOverride = patchType(OverrideType); // outputs 'patched' as proto.hasOwnProperty(__symbol__('method')) == false. Returns the unpatched OverrideType.prototype.method
zone.run(() => {
  typeInstance.method(cb); // 'type patch'
  dummyInstance.method(cb); // 'type patch'
  overrideInstance.method(cb); // 'override patch'
  nativeOverride.apply(overrideInstance, [cb]); // 'override <root>'
});

// this scenario is the same as before
const nativeOverride = patchType(OverrideType); // outputs 'patched'. Returns the unpatched OverrideType.prototype.method
patchType(Type); // outputs 'patched'. Returns the unpatched Type.prototype.method
patchType(Dummy); // no output. Returns the unpatched Type.prototype.method
zone.run(() => {
  typeInstance.method(cb); // 'type patch'
  dummyInstance.method(cb); // 'type patch'
  overrideInstance.method(cb); // 'override patch'
  nativeOverride.apply(overrideInstance, [cb]); // 'override <root>'
});