types(reactivity): support DeepReadonly type

[Picknight]

fix #1452

[yyx990803]

Thanks for the PR! Could you please add a test case in test-dts? (For test format, consult other files in that directory)

[Picknight]

Sure.

[Picknight]

Done. @yyx990803

[jacekkarczmarczyk]

this looks like a breaking change?

[Picknight]

this looks like a breaking change?

This is not a new feature, it just improves type checking.

[jacekkarczmarczyk]

As far as i understand before this PR you could do

r.obj.k = 'x'

and now you can't

How can I now create shallow readonly variable so that

r.obj = {}; // should fail
r.obj.k = 'x'; // should work

?

This is not a new feature

Maybe it should a new feature? Or is shallow readonly considered to be a feature that nobody needs?

[Picknight]

1. Before this PR, if you execute r.obj.k = 'x', actually it will not take effect. Now we have completed the type checking to avoid unnecessary troubles for developers.
2. For shallow readonly variable, you can use shallowReadonly. @jacekkarczmarczyk

[jacekkarczmarczyk]

Before this PR, if you execute r.obj.k = 'x', actually it will not take effect.

Ah I see, that makes perfectly sense