在Angular2中对valueChanges进行空订阅

Question

I have this weird case, a subscribe that never fires if left empty.

This doesn't work:

this.formGroup.get('unitCount').valueChanges
.do(value => console.log(value))
.subscribe();

When this works fine:

this.formGroup.get('unitCount').valueChanges
.do(value => console.log(value))
.subscribe(() => true);

Here I used () => true , but it could anything, false , void 0 , even an empty object {}

Why can't I leave the subscribe() empty?

Answer 1

You probably have a older version of RxJS 5. This was a bug but is already fixed.

I can't find since what version it works correctly, but this PR could be related to this: https://github.com/ReactiveX/rxjs/pull/1935

Otherwise, show what exact RxJS version you're using.