Cannot define a Partial<T> for a constrained T extends Base specifying only members of Base

[pzavolinsky]

TypeScript Version: 2.1.4

Code

interface Base {
  page: number
}

function test<T extends Base>() {
    const firstPage:Partial<T> = { page: 1 };
}

Also reproducible here.

Expected behavior:
firstPage should be accepted as a valid partial instance of T.

Actual behavior:

error TS2322: Type '{ page: 1; }' is not assignable to type 'Partial<T>'.

Also, the error is not very helpful explaining why the type is not assignable.

[pzavolinsky]

Related to #12731.

I believe this should be considered a bug rather than a suggestion (as the issue above).

[mhegazy]

Duplicate of #16356 and #19388

[mhegazy]

Use Partial<Base> instead.

[typescript-bot]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.