Data is not updated when fallbackData and revalidateOnMount: false are provided

[VladimirMikulic]

Bug report

Description / Observed Behavior

Data is not updated when fallbackData and revalidateOnMount: false are provided.
It doesn't matter that the key changes, the actual request is never made to get the new data based on that key.

Expected Behavior

I would expect SWR to fetch new data on key change.

Repro Steps / Code Example

Here's how our code looks like:
(we would like to take advantage of SSG and not request the data on client-side upon mount - only if the key changes)

const getEndpoint = (page, count, filters) => {
   // returns new endpoint based on filters like: https://my-api.com?page=1&count=10&buyPrice=true
}

const Page = ({ fallbackData }) => {
  const [filters, setFilters] = useState(defaultFilters)

  const onChange = () => {
    ...
    setFilters(newFilters)
  }

  // Filters change, new endpoint is generated, but fetcher is never called
  const { data } = useSWRInfinite(
    (pageIndex) => getEndpoint(pageIndex + 1, 10, filters),
    fetcher,
    { fallbackData, revalidateOnMount: false }
  );

  return (...)
}

export async function getServerSideProps(context) {
  const fallbackData = await getFallbackData(context.query);
  
  return {
    props: {
      fallbackData
    },
  };
}

Additional Context

SWR version: 1.2.1
Next.js: 12.0.10

[koba04]

This seems to be fixed by #1837 and please see the test of #1847, so I expect your issue would be solved in the next release.

[koba04]

1.2.2 has been released, so now you can try this on the version.

[VladimirMikulic]

It works! Thank you so much @koba04!