Mocking an empty object using setup and returns

[brooksfolk]

Typemoq tests fail when I try and use '{}' within a setup and return. However, I can create a method that returns a blank object and tests pass.

        TestUtil.testAsync(async () => {
            const mockedUpload = getMockedUpload();
            const blankBody = getBlankBody();
            const req: typemoq.IMock<ExpressRequest> = typemoq.Mock.ofType<ExpressRequest>();
            req.setup(u => u.body).returns(() => blankBody);
            const res: typemoq.IMock<ExpressResponse> = typemoq.Mock.ofType<ExpressResponse>();
            const promise = new Promise<Definitions.Upload>((resolve, reject) => {
            resolve(mockedUpload);
        });
        uploadService.setup(files => files.createUpload(blankBody)).returns(() => promise);

And blank body:

function getBlankBody() {
  return {};
}

The above example works, but if I try to set empty object inline tests fail:

        TestUtil.testAsync(async () => {
            const mockedUpload = getMockedUpload();
            const req: typemoq.IMock<ExpressRequest> = typemoq.Mock.ofType<ExpressRequest>();
            req.setup(u => u.body).returns(() => {});
            const res: typemoq.IMock<ExpressResponse> = typemoq.Mock.ofType<ExpressResponse>();
            const promise = new Promise<Definitions.Upload>((resolve, reject) => {
            resolve(mockedUpload);
        });

        uploadService.setup(files => files.createUpload({})).returns(() => promise);

Please advise.