types: improve useSWRMutation type.

[promer94]

close: #2516
close: #2477

Previous

The return type of trigger will always be Data | undefined

const { trigger } = useSWRMutation('/api/user', fetcher)

expectType<Promise<string | undefined>>(trigger())

Now

The return type of trigger will be Data by default, unless throwOnError is set to false

const { trigger } = useSWRMutation('/api/user', fetcher)

expectType<Promise<string>>(trigger())
expectType<Promise<string | undefined >>(trigger(null, { throwOnError: false }))

const { trigger } = useSWRMutation('/api/user', fetcher, { throwOnError: false })

expectType<Promise<string|undefined>>(trigger())
expectType<Promise<string>>(trigger(null, { throwOnError: true }))

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit da47ab6:

Sandbox	Source
SWR-Basic	Configuration
SWR-States	Configuration
SWR-Infinite	Configuration
SWR-SSR	Configuration

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 8989b60:

Sandbox	Source
SWR-Basic	Configuration
SWR-States	Configuration
SWR-Infinite	Configuration
SWR-SSR	Configuration

[shuding]

Thanks!

[benevbright]

cool. thanks! @promer94