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cea84a41bc
of dependencies from source
---
`validatePreserveExistingMemoizationGuarantees` previously checked
- manual memoization dependencies and declarations (the returned value) do not
"lose" memoization due to inferred mutations
```
function useFoo() {
const y = {};
// bail out because we infer that y cannot be a dependency of x as its
mutableRange
// extends beyond
const x = useMemo(() => maybeMutate(y), [y]);
// similarly, bail out if we find that x or y are mutated here
return x;
}
```
- manual memoization deps and decls do not get deopted due to hook calls
```
function useBar() {
const x = getArray();
useHook();
mutate(x);
return useCallback(() => [x], [x]);
}
```
This PR updates `validatePreserveExistingMemoizationGuarantees` with the
following correctness conditions:
*major change* All inferred dependencies of reactive scopes between
`StartMemoize` and `StopMemoize` instructions (e.g. scopes containing manual
memoization code) must either:
1. be produced from earlier within the same manual memoization block
2. exactly match an element of depslist from source
This assumes that the source codebase mostly follows the `exhaustive-deps` lint
rule, which ensures that deps lists are (1) simple expressions composing of
reads from named identifiers + property loads and (2) exactly match deps usages
in the useMemo/useCallback itself.
---
Validated that this does not change source by running internally on ~50k files
(no validation on `main`, no validation on this PR, and validation on this PR).