103 lines
3.1 KiB
Markdown
103 lines
3.1 KiB
Markdown
|
|
||
|
|
## Input
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
// @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)
|
||
|
|
* <div>{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}</div>
|
||
|
|
* <div>{"cb":{"kind":"Function","result":11},"shouldInvokeFns":true}</div>
|
||
|
|
* Forget:
|
||
|
|
* (kind: ok)
|
||
|
|
* <div>{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}</div>
|
||
|
|
* <div>{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}</div>
|
||
|
|
*/
|
||
|
|
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 <Stringify cb={cb} shouldInvokeFns={true} />;
|
||
|
|
}
|
||
|
|
|
||
|
|
export const FIXTURE_ENTRYPOINT = {
|
||
|
|
fn: useFoo,
|
||
|
|
params: [{a: 2, b: 10}],
|
||
|
|
sequentialRenders: [
|
||
|
|
{a: 2, b: 10},
|
||
|
|
{a: 2, b: 11},
|
||
|
|
],
|
||
|
|
};
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
## Code
|
||
|
|
|
||
|
|
```javascript
|
||
|
|
import { c as _c } from "react/compiler-runtime";
|
||
|
|
import { arrayPush, setPropertyByKey, Stringify } from "shared-runtime";
|
||
|
|
|
||
|
|
function useFoo(t0) {
|
||
|
|
const $ = _c(3);
|
||
|
|
const { a, b } = t0;
|
||
|
|
let t1;
|
||
|
|
if ($[0] !== a || $[1] !== b) {
|
||
|
|
const x = [];
|
||
|
|
const y = { value: a };
|
||
|
|
arrayPush(x, y);
|
||
|
|
const y_alias = y;
|
||
|
|
const cb = () => y_alias.value;
|
||
|
|
setPropertyByKey(x[0], "value", b);
|
||
|
|
t1 = <Stringify cb={cb} shouldInvokeFns={true} />;
|
||
|
|
$[0] = a;
|
||
|
|
$[1] = b;
|
||
|
|
$[2] = t1;
|
||
|
|
} else {
|
||
|
|
t1 = $[2];
|
||
|
|
}
|
||
|
|
return t1;
|
||
|
|
}
|
||
|
|
|
||
|
|
export const FIXTURE_ENTRYPOINT = {
|
||
|
|
fn: useFoo,
|
||
|
|
params: [{ a: 2, b: 10 }],
|
||
|
|
sequentialRenders: [
|
||
|
|
{ a: 2, b: 10 },
|
||
|
|
{ a: 2, b: 11 },
|
||
|
|
],
|
||
|
|
};
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
### Eval output
|
||
|
|
(kind: ok) <div>{"cb":{"kind":"Function","result":10},"shouldInvokeFns":true}</div>
|
||
|
|
<div>{"cb":{"kind":"Function","result":11},"shouldInvokeFns":true}</div>
|