// @flow @enableTransitivelyFreezeFunctionExpressions:false @enableNewMutationAliasingModel import {arrayPush, setPropertyByKey, Stringify} from 'shared-runtime'; /** * Repro of a bug fixed in the new aliasing model. * * 1. `InferMutableRanges` derives the mutable range of identifiers and their * aliases from `LoadLocal`, `PropertyLoad`, etc * - After this pass, y's mutable range only extends to `arrayPush(x, y)` * - We avoid assigning mutable ranges to loads after y's mutable range, as * these are working with an immutable value. As a result, `LoadLocal y` and * `PropertyLoad y` do not get mutable ranges * 2. `InferReactiveScopeVariables` extends mutable ranges and creates scopes, * as according to the 'co-mutation' of different values * - Here, we infer that * - `arrayPush(y, x)` might alias `x` and `y` to each other * - `setPropertyKey(x, ...)` may mutate both `x` and `y` * - This pass correctly extends the mutable range of `y` * - Since we didn't run `InferMutableRange` logic again, the LoadLocal / * PropertyLoads still don't have a mutable range * * Note that the this bug is an edge case. Compiler output is only invalid for: * - function expressions with * `enableTransitivelyFreezeFunctionExpressions:false` * - functions that throw and get retried without clearing the memocache * * Found differences in evaluator results * Non-forget (expected): * (kind: ok) *
{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}
*
{"cb":{"kind":"Function","result":11},"shouldInvokeFns":true}
* Forget: * (kind: ok) *
{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}
*
{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}
*/ function useFoo({a, b}: {a: number, b: number}) { const x = []; const y = {value: a}; arrayPush(x, y); // x and y co-mutate const y_alias = y; const cb = () => y_alias.value; setPropertyByKey(x[0], 'value', b); // might overwrite y.value return ; } export const FIXTURE_ENTRYPOINT = { fn: useFoo, params: [{a: 2, b: 10}], sequentialRenders: [ {a: 2, b: 10}, {a: 2, b: 11}, ], };