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...

7 Commits

Author SHA1 Message Date
Jorge Cabiedes Acosta
0fae264d51 [compiler] _exp version of ValidateNoDerivedComputationsInEffects take precedence over stable version when enabled
Summary:
We should only run one version of the validation. I think it makes sense that if the exp version is enable it takes precedence over the stable one
2025-11-11 09:19:40 -08:00
Jorge Cabiedes Acosta
2ac39db287 [compiler] Update test snap to include fixture comment
Summary:
I missed this test case failing and now having @loggerTestOnly after landing some other PRs good to know they're not land blocking
2025-11-11 09:19:40 -08:00
Jorge Cabiedes
100fc4a8cf [compiler] Prevent local state source variables from depending on other state (#35044)
Summary:
When a local state is created sometimes it uses a `prop` or even other
local state for its initial value.

This value is only relevant on first render so we shouldn't consider it
part of our data flow

Test Plan:
Added tests
2025-11-10 12:29:34 -08:00
Jorge Cabiedes
92ac4e8b80 [compiler] Don't validate when effect cleanup function depends on effect localized setState state derived values (#35020)
Summary:
If we are using a clean up function in an effect and that clean up
function depends on a value that is used to set the state we are
validating for we shouldn't throw an error since it is a valid use case
for an effect.

Test Plan:
added test

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/35020).
* #35044
* __->__ #35020
2025-11-10 12:28:19 -08:00
Jorge Cabiedes
f76c3617e0 [compiler] Switch to track setStates by aliasing and id instead of identifier names (#34973)
Summary:
This makes the setState usage logic much more robust. We no longer rely
on identifierName.

Now we track when a setState is loaded into a new promoted identifier
variable and track this in a map `setStateLoaded` map.

For other types of instructions we consider the setState to be being
used. In this case we record its usage into the `setStateUsages` map.



Test Plan:
We expect no changes in behavior for the current tests

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34973).
* #35044
* #35020
* __->__ #34973
* #34972
2025-11-10 12:16:27 -08:00
Jorge Cabiedes
7296120396 [compiler] Update ValidateNoDerivedComputationsInEffects_exp to log the error instead of throwing (#34972)
Summary:
TSIA

Simple change to log errors in Pipeline.ts instead of throwing in the
validation

Test Plan:
updated snap tests

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34972).
* #35044
* #35020
* #34973
* __->__ #34972
2025-11-10 12:16:13 -08:00
Jorge Cabiedes
6347c6d373 [compiler] Fix false negatives and add data flow tree to compiler error for no-deriving-state-in-effects (#34995)
Summary:
Revamped the derivationCache graph.

This fixes a bunch of bugs where sometimes we fail to track from which
props/state we derived values from.

Also, it is more intuitive and allows us to easily implement a Data Flow
Tree.

We can print this tree which gives insight on how the data is derived
and should facilitate error resolution in complicated components

Test Plan:
Added a test case where we were failing to track derivations. Also
updated the test cases with the new error containing the data flow tree

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34995).
* #35044
* #35020
* #34973
* #34972
* __->__ #34995
* #34967
2025-11-10 12:09:13 -08:00
47 changed files with 1427 additions and 560 deletions

View File

@@ -272,12 +272,10 @@ function runWithEnvironment(
validateNoSetStateInRender(hir).unwrap();
}
if (env.config.validateNoDerivedComputationsInEffects) {
validateNoDerivedComputationsInEffects(hir);
}
if (env.config.validateNoDerivedComputationsInEffects_exp) {
validateNoDerivedComputationsInEffects_exp(hir);
env.logErrors(validateNoDerivedComputationsInEffects_exp(hir));
} else if (env.config.validateNoDerivedComputationsInEffects) {
validateNoDerivedComputationsInEffects(hir);
}
if (env.config.validateNoSetStateInEffects) {

View File

@@ -5,6 +5,7 @@
* LICENSE file in the root directory of this source tree.
*/
import {Result} from '../Utils/Result';
import {CompilerDiagnostic, CompilerError, Effect} from '..';
import {ErrorCategory} from '../CompilerError';
import {
@@ -20,7 +21,6 @@ import {
isUseStateType,
BasicBlock,
isUseRefType,
GeneratedSource,
SourceLocation,
} from '../HIR';
import {eachInstructionLValue, eachInstructionOperand} from '../HIR/visitors';
@@ -33,6 +33,7 @@ type DerivationMetadata = {
typeOfValue: TypeOfValue;
place: Place;
sourcesIds: Set<IdentifierId>;
isStateSource: boolean;
};
type ValidationContext = {
@@ -40,8 +41,8 @@ type ValidationContext = {
readonly errors: CompilerError;
readonly derivationCache: DerivationCache;
readonly effects: Set<HIRFunction>;
readonly setStateCache: Map<string | undefined | null, Array<Place>>;
readonly effectSetStateCache: Map<string | undefined | null, Array<Place>>;
readonly setStateLoads: Map<IdentifierId, IdentifierId | null>;
readonly setStateUsages: Map<IdentifierId, Set<SourceLocation>>;
};
class DerivationCache {
@@ -56,6 +57,7 @@ class DerivationCache {
place: value.place,
sourcesIds: new Set(value.sourcesIds),
typeOfValue: value.typeOfValue,
isStateSource: value.isStateSource,
});
}
}
@@ -95,41 +97,28 @@ class DerivationCache {
derivedVar: Place,
sourcesIds: Set<IdentifierId>,
typeOfValue: TypeOfValue,
isStateSource: boolean,
): void {
let newValue: DerivationMetadata = {
place: derivedVar,
sourcesIds: new Set(),
typeOfValue: typeOfValue ?? 'ignored',
};
if (sourcesIds !== undefined) {
for (const id of sourcesIds) {
const sourcePlace = this.cache.get(id)?.place;
if (sourcePlace === undefined) {
continue;
}
/*
* If the identifier of the source is a promoted identifier, then
* we should set the target as the source.
*/
let finalIsSource = isStateSource;
if (!finalIsSource) {
for (const sourceId of sourcesIds) {
const sourceMetadata = this.cache.get(sourceId);
if (
sourcePlace.identifier.name === null ||
sourcePlace.identifier.name?.kind === 'promoted'
sourceMetadata?.isStateSource &&
sourceMetadata.place.identifier.name?.kind !== 'named'
) {
newValue.sourcesIds.add(derivedVar.identifier.id);
} else {
newValue.sourcesIds.add(sourcePlace.identifier.id);
finalIsSource = true;
break;
}
}
}
if (newValue.sourcesIds.size === 0) {
newValue.sourcesIds.add(derivedVar.identifier.id);
}
this.cache.set(derivedVar.identifier.id, newValue);
this.cache.set(derivedVar.identifier.id, {
place: derivedVar,
sourcesIds: sourcesIds,
typeOfValue: typeOfValue ?? 'ignored',
isStateSource: finalIsSource,
});
}
private isDerivationEqual(
@@ -151,6 +140,14 @@ class DerivationCache {
}
}
function isNamedIdentifier(place: Place): place is Place & {
identifier: {name: NonNullable<Place['identifier']['name']>};
} {
return (
place.identifier.name !== null && place.identifier.name.kind === 'named'
);
}
/**
* Validates that useEffect is not used for derived computations which could/should
* be performed in render.
@@ -176,25 +173,22 @@ class DerivationCache {
*/
export function validateNoDerivedComputationsInEffects_exp(
fn: HIRFunction,
): void {
): Result<void, CompilerError> {
const functions: Map<IdentifierId, FunctionExpression> = new Map();
const derivationCache = new DerivationCache();
const errors = new CompilerError();
const effects: Set<HIRFunction> = new Set();
const setStateCache: Map<string | undefined | null, Array<Place>> = new Map();
const effectSetStateCache: Map<
string | undefined | null,
Array<Place>
> = new Map();
const setStateLoads: Map<IdentifierId, IdentifierId> = new Map();
const setStateUsages: Map<IdentifierId, Set<SourceLocation>> = new Map();
const context: ValidationContext = {
functions,
errors,
derivationCache,
effects,
setStateCache,
effectSetStateCache,
setStateLoads,
setStateUsages,
};
if (fn.fnType === 'Hook') {
@@ -202,8 +196,9 @@ export function validateNoDerivedComputationsInEffects_exp(
if (param.kind === 'Identifier') {
context.derivationCache.cache.set(param.identifier.id, {
place: param,
sourcesIds: new Set([param.identifier.id]),
sourcesIds: new Set(),
typeOfValue: 'fromProps',
isStateSource: true,
});
}
}
@@ -212,8 +207,9 @@ export function validateNoDerivedComputationsInEffects_exp(
if (props != null && props.kind === 'Identifier') {
context.derivationCache.cache.set(props.identifier.id, {
place: props,
sourcesIds: new Set([props.identifier.id]),
sourcesIds: new Set(),
typeOfValue: 'fromProps',
isStateSource: true,
});
}
}
@@ -237,9 +233,7 @@ export function validateNoDerivedComputationsInEffects_exp(
validateEffect(effect, context);
}
if (errors.hasAnyErrors()) {
throw errors;
}
return errors.asResult();
}
function recordPhiDerivations(
@@ -267,6 +261,7 @@ function recordPhiDerivations(
phi.place,
sourcesIds,
typeOfValue,
false,
);
}
}
@@ -282,17 +277,69 @@ function joinValue(
return 'fromPropsAndState';
}
function getRootSetState(
key: IdentifierId,
loads: Map<IdentifierId, IdentifierId | null>,
visited: Set<IdentifierId> = new Set(),
): IdentifierId | null {
if (visited.has(key)) {
return null;
}
visited.add(key);
const parentId = loads.get(key);
if (parentId === undefined) {
return null;
}
if (parentId === null) {
return key;
}
return getRootSetState(parentId, loads, visited);
}
function maybeRecordSetState(
instr: Instruction,
loads: Map<IdentifierId, IdentifierId | null>,
usages: Map<IdentifierId, Set<SourceLocation>>,
): void {
for (const operand of eachInstructionLValue(instr)) {
if (
instr.value.kind === 'LoadLocal' &&
loads.has(instr.value.place.identifier.id)
) {
loads.set(operand.identifier.id, instr.value.place.identifier.id);
} else {
if (isSetStateType(operand.identifier)) {
// this is a root setState
loads.set(operand.identifier.id, null);
}
}
const rootSetState = getRootSetState(operand.identifier.id, loads);
if (rootSetState !== null && usages.get(rootSetState) === undefined) {
usages.set(rootSetState, new Set([operand.loc]));
}
}
}
function recordInstructionDerivations(
instr: Instruction,
context: ValidationContext,
isFirstPass: boolean,
): void {
maybeRecordSetState(instr, context.setStateLoads, context.setStateUsages);
let typeOfValue: TypeOfValue = 'ignored';
let isSource: boolean = false;
const sources: Set<IdentifierId> = new Set();
const {lvalue, value} = instr;
if (value.kind === 'FunctionExpression') {
context.functions.set(lvalue.identifier.id, value);
for (const [, block] of value.loweredFunc.func.body.blocks) {
recordPhiDerivations(block, context);
for (const instr of block.instructions) {
recordInstructionDerivations(instr, context, isFirstPass);
}
@@ -311,24 +358,25 @@ function recordInstructionDerivations(
context.effects.add(effectFunction.loweredFunc.func);
}
} else if (isUseStateType(lvalue.identifier) && value.args.length > 0) {
const stateValueSource = value.args[0];
if (stateValueSource.kind === 'Identifier') {
sources.add(stateValueSource.identifier.id);
}
typeOfValue = joinValue(typeOfValue, 'fromState');
typeOfValue = 'fromState';
context.derivationCache.addDerivationEntry(
lvalue,
new Set(),
typeOfValue,
true,
);
return;
}
}
for (const operand of eachInstructionOperand(instr)) {
if (
isSetStateType(operand.identifier) &&
operand.loc !== GeneratedSource &&
isFirstPass
) {
if (context.setStateCache.has(operand.loc.identifierName)) {
context.setStateCache.get(operand.loc.identifierName)!.push(operand);
} else {
context.setStateCache.set(operand.loc.identifierName, [operand]);
if (context.setStateLoads.has(operand.identifier.id)) {
const rootSetStateId = getRootSetState(
operand.identifier.id,
context.setStateLoads,
);
if (rootSetStateId !== null) {
context.setStateUsages.get(rootSetStateId)?.add(operand.loc);
}
}
@@ -341,9 +389,7 @@ function recordInstructionDerivations(
}
typeOfValue = joinValue(typeOfValue, operandMetadata.typeOfValue);
for (const id of operandMetadata.sourcesIds) {
sources.add(id);
}
sources.add(operand.identifier.id);
}
if (typeOfValue === 'ignored') {
@@ -351,7 +397,12 @@ function recordInstructionDerivations(
}
for (const lvalue of eachInstructionLValue(instr)) {
context.derivationCache.addDerivationEntry(lvalue, sources, typeOfValue);
context.derivationCache.addDerivationEntry(
lvalue,
sources,
typeOfValue,
isSource,
);
}
for (const operand of eachInstructionOperand(instr)) {
@@ -378,6 +429,7 @@ function recordInstructionDerivations(
operand,
sources,
typeOfValue,
false,
);
}
}
@@ -411,6 +463,137 @@ function recordInstructionDerivations(
}
}
type TreeNode = {
name: string;
typeOfValue: TypeOfValue;
isSource: boolean;
children: Array<TreeNode>;
};
function buildTreeNode(
sourceId: IdentifierId,
context: ValidationContext,
visited: Set<string> = new Set(),
): Array<TreeNode> {
const sourceMetadata = context.derivationCache.cache.get(sourceId);
if (!sourceMetadata) {
return [];
}
if (sourceMetadata.isStateSource && isNamedIdentifier(sourceMetadata.place)) {
return [
{
name: sourceMetadata.place.identifier.name.value,
typeOfValue: sourceMetadata.typeOfValue,
isSource: sourceMetadata.isStateSource,
children: [],
},
];
}
const children: Array<TreeNode> = [];
const namedSiblings: Set<string> = new Set();
for (const childId of sourceMetadata.sourcesIds) {
const childNodes = buildTreeNode(
childId,
context,
new Set([
...visited,
...(isNamedIdentifier(sourceMetadata.place)
? [sourceMetadata.place.identifier.name.value]
: []),
]),
);
if (childNodes) {
for (const childNode of childNodes) {
if (!namedSiblings.has(childNode.name)) {
children.push(childNode);
namedSiblings.add(childNode.name);
}
}
}
}
if (
isNamedIdentifier(sourceMetadata.place) &&
!visited.has(sourceMetadata.place.identifier.name.value)
) {
return [
{
name: sourceMetadata.place.identifier.name.value,
typeOfValue: sourceMetadata.typeOfValue,
isSource: sourceMetadata.isStateSource,
children: children,
},
];
}
return children;
}
function renderTree(
node: TreeNode,
indent: string = '',
isLast: boolean = true,
propsSet: Set<string>,
stateSet: Set<string>,
): string {
const prefix = indent + (isLast ? '└── ' : '├── ');
const childIndent = indent + (isLast ? ' ' : '│ ');
let result = `${prefix}${node.name}`;
if (node.isSource) {
let typeLabel: string;
if (node.typeOfValue === 'fromProps') {
propsSet.add(node.name);
typeLabel = 'Prop';
} else if (node.typeOfValue === 'fromState') {
stateSet.add(node.name);
typeLabel = 'State';
} else {
propsSet.add(node.name);
stateSet.add(node.name);
typeLabel = 'Prop and State';
}
result += ` (${typeLabel})`;
}
if (node.children.length > 0) {
result += '\n';
node.children.forEach((child, index) => {
const isLastChild = index === node.children.length - 1;
result += renderTree(child, childIndent, isLastChild, propsSet, stateSet);
if (index < node.children.length - 1) {
result += '\n';
}
});
}
return result;
}
function getFnLocalDeps(
fn: FunctionExpression | undefined,
): Set<IdentifierId> | undefined {
if (!fn) {
return undefined;
}
const deps: Set<IdentifierId> = new Set();
for (const [, block] of fn.loweredFunc.func.body.blocks) {
for (const instr of block.instructions) {
if (instr.value.kind === 'LoadLocal') {
deps.add(instr.value.place.identifier.id);
}
}
}
return deps;
}
function validateEffect(
effectFunction: HIRFunction,
context: ValidationContext,
@@ -419,13 +602,33 @@ function validateEffect(
const effectDerivedSetStateCalls: Array<{
value: CallExpression;
loc: SourceLocation;
id: IdentifierId;
sourceIds: Set<IdentifierId>;
typeOfValue: TypeOfValue;
}> = [];
const effectSetStateUsages: Map<
IdentifierId,
Set<SourceLocation>
> = new Map();
let cleanUpFunctionDeps: Set<IdentifierId> | undefined;
const globals: Set<IdentifierId> = new Set();
for (const block of effectFunction.body.blocks.values()) {
/*
* if the block is in an effect and is of type return then its an effect's cleanup function
* if the cleanup function depends on a value from which effect-set state is derived then
* we can't validate
*/
if (
block.terminal.kind === 'return' &&
block.terminal.returnVariant === 'Explicit'
) {
cleanUpFunctionDeps = getFnLocalDeps(
context.functions.get(block.terminal.value.identifier.id),
);
}
for (const pred of block.preds) {
if (!seenBlocks.has(pred)) {
// skip if block has a back edge
@@ -439,19 +642,16 @@ function validateEffect(
return;
}
maybeRecordSetState(instr, context.setStateLoads, effectSetStateUsages);
for (const operand of eachInstructionOperand(instr)) {
if (
isSetStateType(operand.identifier) &&
operand.loc !== GeneratedSource
) {
if (context.effectSetStateCache.has(operand.loc.identifierName)) {
context.effectSetStateCache
.get(operand.loc.identifierName)!
.push(operand);
} else {
context.effectSetStateCache.set(operand.loc.identifierName, [
operand,
]);
if (context.setStateLoads.has(operand.identifier.id)) {
const rootSetStateId = getRootSetState(
operand.identifier.id,
context.setStateLoads,
);
if (rootSetStateId !== null) {
effectSetStateUsages.get(rootSetStateId)?.add(operand.loc);
}
}
}
@@ -469,7 +669,7 @@ function validateEffect(
if (argMetadata !== undefined) {
effectDerivedSetStateCalls.push({
value: instr.value,
loc: instr.value.callee.loc,
id: instr.value.callee.identifier.id,
sourceIds: argMetadata.sourcesIds,
typeOfValue: argMetadata.typeOfValue,
});
@@ -503,37 +703,74 @@ function validateEffect(
}
for (const derivedSetStateCall of effectDerivedSetStateCalls) {
const rootSetStateCall = getRootSetState(
derivedSetStateCall.id,
context.setStateLoads,
);
if (
derivedSetStateCall.loc !== GeneratedSource &&
context.effectSetStateCache.has(derivedSetStateCall.loc.identifierName) &&
context.setStateCache.has(derivedSetStateCall.loc.identifierName) &&
context.effectSetStateCache.get(derivedSetStateCall.loc.identifierName)!
.length ===
context.setStateCache.get(derivedSetStateCall.loc.identifierName)!
.length -
1
rootSetStateCall !== null &&
effectSetStateUsages.has(rootSetStateCall) &&
context.setStateUsages.has(rootSetStateCall) &&
effectSetStateUsages.get(rootSetStateCall)!.size ===
context.setStateUsages.get(rootSetStateCall)!.size - 1
) {
const derivedDepsStr = Array.from(derivedSetStateCall.sourceIds)
.map(sourceId => {
const sourceMetadata = context.derivationCache.cache.get(sourceId);
return sourceMetadata?.place.identifier.name?.value;
})
.filter(Boolean)
.join(', ');
const propsSet = new Set<string>();
const stateSet = new Set<string>();
let description;
if (derivedSetStateCall.typeOfValue === 'fromProps') {
description = `From props: [${derivedDepsStr}]`;
} else if (derivedSetStateCall.typeOfValue === 'fromState') {
description = `From local state: [${derivedDepsStr}]`;
} else {
description = `From props and local state: [${derivedDepsStr}]`;
const rootNodesMap = new Map<string, TreeNode>();
for (const id of derivedSetStateCall.sourceIds) {
const nodes = buildTreeNode(id, context);
for (const node of nodes) {
if (!rootNodesMap.has(node.name)) {
rootNodesMap.set(node.name, node);
}
}
}
const rootNodes = Array.from(rootNodesMap.values());
const trees = rootNodes.map((node, index) =>
renderTree(
node,
'',
index === rootNodes.length - 1,
propsSet,
stateSet,
),
);
for (const dep of derivedSetStateCall.sourceIds) {
if (cleanUpFunctionDeps !== undefined && cleanUpFunctionDeps.has(dep)) {
return;
}
}
const propsArr = Array.from(propsSet);
const stateArr = Array.from(stateSet);
let rootSources = '';
if (propsArr.length > 0) {
rootSources += `Props: [${propsArr.join(', ')}]`;
}
if (stateArr.length > 0) {
if (rootSources) rootSources += '\n';
rootSources += `State: [${stateArr.join(', ')}]`;
}
const description = `Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user
This setState call is setting a derived value that depends on the following reactive sources:
${rootSources}
Data Flow Tree:
${trees.join('\n')}
See: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state`;
context.errors.pushDiagnostic(
CompilerDiagnostic.create({
description: `Derived values (${description}) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user`,
description: description,
category: ErrorCategory.EffectDerivationsOfState,
reason:
'You might not need an effect. Derive values in render, not effects.',

View File

@@ -0,0 +1,86 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({value, enabled}) {
const [localValue, setLocalValue] = useState('');
useEffect(() => {
if (enabled) {
setLocalValue(value);
} else {
setLocalValue('disabled');
}
}, [value, enabled]);
return <div>{localValue}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{value: 'test', enabled: true}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
const $ = _c(6);
const { value, enabled } = t0;
const [localValue, setLocalValue] = useState("");
let t1;
let t2;
if ($[0] !== enabled || $[1] !== value) {
t1 = () => {
if (enabled) {
setLocalValue(value);
} else {
setLocalValue("disabled");
}
};
t2 = [value, enabled];
$[0] = enabled;
$[1] = value;
$[2] = t1;
$[3] = t2;
} else {
t1 = $[2];
t2 = $[3];
}
useEffect(t1, t2);
let t3;
if ($[4] !== localValue) {
t3 = <div>{localValue}</div>;
$[4] = localValue;
$[5] = t3;
} else {
t3 = $[5];
}
return t3;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ value: "test", enabled: true }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [value]\n\nData Flow Tree:\n└── value (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":6,"index":244},"end":{"line":9,"column":19,"index":257},"filename":"derived-state-conditionally-in-effect.ts","identifierName":"setLocalValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":16,"column":1,"index":378},"filename":"derived-state-conditionally-in-effect.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>test</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({value, enabled}) {

View File

@@ -0,0 +1,78 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
export default function Component({input = 'empty'}) {
const [currInput, setCurrInput] = useState(input);
const localConst = 'local const';
useEffect(() => {
setCurrInput(input + localConst);
}, [input, localConst]);
return <div>{currInput}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{input: 'test'}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
export default function Component(t0) {
const $ = _c(5);
const { input: t1 } = t0;
const input = t1 === undefined ? "empty" : t1;
const [currInput, setCurrInput] = useState(input);
let t2;
let t3;
if ($[0] !== input) {
t2 = () => {
setCurrInput(input + "local const");
};
t3 = [input, "local const"];
$[0] = input;
$[1] = t2;
$[2] = t3;
} else {
t2 = $[1];
t3 = $[2];
}
useEffect(t2, t3);
let t4;
if ($[3] !== currInput) {
t4 = <div>{currInput}</div>;
$[3] = currInput;
$[4] = t4;
} else {
t4 = $[4];
}
return t4;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ input: "test" }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [input]\n\nData Flow Tree:\n└── input (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":4,"index":276},"end":{"line":9,"column":16,"index":288},"filename":"derived-state-from-default-props.ts","identifierName":"setCurrInput"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":122},"end":{"line":13,"column":1,"index":372},"filename":"derived-state-from-default-props.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>testlocal const</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
export default function Component({input = 'empty'}) {

View File

@@ -0,0 +1,77 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({shouldChange}) {
const [count, setCount] = useState(0);
useEffect(() => {
if (shouldChange) {
setCount(count + 1);
}
}, [count]);
return <div>{count}</div>;
}
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
const $ = _c(7);
const { shouldChange } = t0;
const [count, setCount] = useState(0);
let t1;
if ($[0] !== count || $[1] !== shouldChange) {
t1 = () => {
if (shouldChange) {
setCount(count + 1);
}
};
$[0] = count;
$[1] = shouldChange;
$[2] = t1;
} else {
t1 = $[2];
}
let t2;
if ($[3] !== count) {
t2 = [count];
$[3] = count;
$[4] = t2;
} else {
t2 = $[4];
}
useEffect(t1, t2);
let t3;
if ($[5] !== count) {
t3 = <div>{count}</div>;
$[5] = count;
$[6] = t3;
} else {
t3 = $[6];
}
return t3;
}
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [count]\n\nData Flow Tree:\n└── count (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":10,"column":6,"index":237},"end":{"line":10,"column":14,"index":245},"filename":"derived-state-from-local-state-in-effect.ts","identifierName":"setCount"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":108},"end":{"line":15,"column":1,"index":310},"filename":"derived-state-from-local-state-in-effect.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: exception) Fixture not implemented

View File

@@ -0,0 +1,115 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({firstName}) {
const [lastName, setLastName] = useState('Doe');
const [fullName, setFullName] = useState('John');
const middleName = 'D.';
useEffect(() => {
setFullName(firstName + ' ' + middleName + ' ' + lastName);
}, [firstName, middleName, lastName]);
return (
<div>
<input value={lastName} onChange={e => setLastName(e.target.value)} />
<div>{fullName}</div>
</div>
);
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{firstName: 'John'}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
const $ = _c(12);
const { firstName } = t0;
const [lastName, setLastName] = useState("Doe");
const [fullName, setFullName] = useState("John");
let t1;
let t2;
if ($[0] !== firstName || $[1] !== lastName) {
t1 = () => {
setFullName(firstName + " " + "D." + " " + lastName);
};
t2 = [firstName, "D.", lastName];
$[0] = firstName;
$[1] = lastName;
$[2] = t1;
$[3] = t2;
} else {
t1 = $[2];
t2 = $[3];
}
useEffect(t1, t2);
let t3;
if ($[4] === Symbol.for("react.memo_cache_sentinel")) {
t3 = (e) => setLastName(e.target.value);
$[4] = t3;
} else {
t3 = $[4];
}
let t4;
if ($[5] !== lastName) {
t4 = <input value={lastName} onChange={t3} />;
$[5] = lastName;
$[6] = t4;
} else {
t4 = $[6];
}
let t5;
if ($[7] !== fullName) {
t5 = <div>{fullName}</div>;
$[7] = fullName;
$[8] = t5;
} else {
t5 = $[8];
}
let t6;
if ($[9] !== t4 || $[10] !== t5) {
t6 = (
<div>
{t4}
{t5}
</div>
);
$[9] = t4;
$[10] = t5;
$[11] = t6;
} else {
t6 = $[11];
}
return t6;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ firstName: "John" }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [firstName]\nState: [lastName]\n\nData Flow Tree:\n├── firstName (Prop)\n└── lastName (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":11,"column":4,"index":297},"end":{"line":11,"column":15,"index":308},"filename":"derived-state-from-prop-local-state-and-component-scope.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":20,"column":1,"index":542},"filename":"derived-state-from-prop-local-state-and-component-scope.ts"},"fnName":"Component","memoSlots":12,"memoBlocks":5,"memoValues":6,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div><input value="Doe"><div>John D. Doe</div></div>

View File

@@ -2,7 +2,7 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({initialName}) {
@@ -29,7 +29,7 @@ export const FIXTURE_ENTRYPOINT = {
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
@@ -79,6 +79,12 @@ export const FIXTURE_ENTRYPOINT = {
};
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":16,"column":1,"index":359},"filename":"derived-state-from-prop-setter-call-outside-effect-no-error.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":3,"memoValues":4,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div><input value="John"></div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({initialName}) {

View File

@@ -0,0 +1,57 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
function Component({value}) {
const [checked, setChecked] = useState('');
useEffect(() => {
setChecked(value === '' ? [] : value.split(','));
}, [value]);
return <div>{checked}</div>;
}
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
function Component(t0) {
const $ = _c(5);
const { value } = t0;
const [checked, setChecked] = useState("");
let t1;
let t2;
if ($[0] !== value) {
t1 = () => {
setChecked(value === "" ? [] : value.split(","));
};
t2 = [value];
$[0] = value;
$[1] = t1;
$[2] = t2;
} else {
t1 = $[1];
t2 = $[2];
}
useEffect(t1, t2);
let t3;
if ($[3] !== checked) {
t3 = <div>{checked}</div>;
$[3] = checked;
$[4] = t3;
} else {
t3 = $[4];
}
return t3;
}
```
### Eval output
(kind: exception) Fixture not implemented

View File

@@ -0,0 +1,11 @@
// @validateNoDerivedComputationsInEffects_exp
function Component({value}) {
const [checked, setChecked] = useState('');
useEffect(() => {
setChecked(value === '' ? [] : value.split(','));
}, [value]);
return <div>{checked}</div>;
}

View File

@@ -2,7 +2,7 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function MockComponent({onSet}) {
@@ -28,7 +28,7 @@ export const FIXTURE_ENTRYPOINT = {
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function MockComponent(t0) {
@@ -80,6 +80,13 @@ export const FIXTURE_ENTRYPOINT = {
};
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":6,"column":1,"index":211},"filename":"derived-state-from-prop-setter-used-outside-effect-no-error.ts"},"fnName":"MockComponent","memoSlots":2,"memoBlocks":1,"memoValues":1,"prunedMemoBlocks":0,"prunedMemoValues":0}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":8,"column":0,"index":213},"end":{"line":15,"column":1,"index":402},"filename":"derived-state-from-prop-setter-used-outside-effect-no-error.ts"},"fnName":"Component","memoSlots":4,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>Mock Component</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function MockComponent({onSet}) {

View File

@@ -0,0 +1,78 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({value}) {
const [localValue, setLocalValue] = useState('');
useEffect(() => {
setLocalValue(value);
document.title = `Value: ${value}`;
}, [value]);
return <div>{localValue}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{value: 'test'}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
const $ = _c(5);
const { value } = t0;
const [localValue, setLocalValue] = useState("");
let t1;
let t2;
if ($[0] !== value) {
t1 = () => {
setLocalValue(value);
document.title = `Value: ${value}`;
};
t2 = [value];
$[0] = value;
$[1] = t1;
$[2] = t2;
} else {
t1 = $[1];
t2 = $[2];
}
useEffect(t1, t2);
let t3;
if ($[3] !== localValue) {
t3 = <div>{localValue}</div>;
$[3] = localValue;
$[4] = t3;
} else {
t3 = $[4];
}
return t3;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ value: "test" }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [value]\n\nData Flow Tree:\n└── value (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":8,"column":4,"index":214},"end":{"line":8,"column":17,"index":227},"filename":"derived-state-from-prop-with-side-effect.ts","identifierName":"setLocalValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":13,"column":1,"index":327},"filename":"derived-state-from-prop-with-side-effect.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>test</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({value}) {

View File

@@ -2,7 +2,7 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState, useRef} from 'react';
export default function Component({test}) {
@@ -27,7 +27,7 @@ export const FIXTURE_ENTRYPOINT = {
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState, useRef } from "react";
export default function Component(t0) {
@@ -68,6 +68,12 @@ export const FIXTURE_ENTRYPOINT = {
};
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":130},"end":{"line":14,"column":1,"index":328},"filename":"derived-state-from-ref-and-state-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) nulltestString

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState, useRef} from 'react';
export default function Component({test}) {

View File

@@ -0,0 +1,93 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({propValue}) {
const [value, setValue] = useState(null);
function localFunction() {
console.log('local function');
}
useEffect(() => {
setValue(propValue);
localFunction();
}, [propValue]);
return <div>{value}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{propValue: 'test'}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
const $ = _c(6);
const { propValue } = t0;
const [value, setValue] = useState(null);
let t1;
if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
t1 = function localFunction() {
console.log("local function");
};
$[0] = t1;
} else {
t1 = $[0];
}
const localFunction = t1;
let t2;
let t3;
if ($[1] !== propValue) {
t2 = () => {
setValue(propValue);
localFunction();
};
t3 = [propValue];
$[1] = propValue;
$[2] = t2;
$[3] = t3;
} else {
t2 = $[2];
t3 = $[3];
}
useEffect(t2, t3);
let t4;
if ($[4] !== value) {
t4 = <div>{value}</div>;
$[4] = value;
$[5] = t4;
} else {
t4 = $[5];
}
return t4;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ propValue: "test" }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [propValue]\n\nData Flow Tree:\n└── propValue (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":12,"column":4,"index":279},"end":{"line":12,"column":12,"index":287},"filename":"effect-contains-local-function-call.ts","identifierName":"setValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":17,"column":1,"index":371},"filename":"effect-contains-local-function-call.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":3,"memoValues":4,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>test</div>
logs: ['local function']

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({propValue}) {

View File

@@ -2,7 +2,7 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({propValue, onChange}) {
@@ -25,7 +25,7 @@ export const FIXTURE_ENTRYPOINT = {
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
@@ -70,6 +70,13 @@ export const FIXTURE_ENTRYPOINT = {
};
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":12,"column":1,"index":306},"filename":"effect-contains-prop-function-call-no-error.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":3,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":16,"column":41,"index":402},"end":{"line":16,"column":49,"index":410},"filename":"effect-contains-prop-function-call-no-error.ts"},"fnName":null,"memoSlots":0,"memoBlocks":0,"memoValues":0,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>test</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({propValue, onChange}) {

View File

@@ -0,0 +1,76 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component(file: File) {
const [imageUrl, setImageUrl] = useState(null);
/*
* Cleaning up the variable or a source of the variable used to setState
* inside the effect communicates that we always need to clean up something
* which is a valid use case for useEffect. In which case we want to
* avoid an throwing
*/
useEffect(() => {
const imageUrlPrepared = URL.createObjectURL(file);
setImageUrl(imageUrlPrepared);
return () => URL.revokeObjectURL(imageUrlPrepared);
}, [file]);
return <Image src={imageUrl} xstyle={styles.imageSizeLimits} />;
}
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(file) {
const $ = _c(5);
const [imageUrl, setImageUrl] = useState(null);
let t0;
let t1;
if ($[0] !== file) {
t0 = () => {
const imageUrlPrepared = URL.createObjectURL(file);
setImageUrl(imageUrlPrepared);
return () => URL.revokeObjectURL(imageUrlPrepared);
};
t1 = [file];
$[0] = file;
$[1] = t0;
$[2] = t1;
} else {
t0 = $[1];
t1 = $[2];
}
useEffect(t0, t1);
let t2;
if ($[3] !== imageUrl) {
t2 = <Image src={imageUrl} xstyle={styles.imageSizeLimits} />;
$[3] = imageUrl;
$[4] = t2;
} else {
t2 = $[4];
}
return t2;
}
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":108},"end":{"line":21,"column":1,"index":700},"filename":"effect-with-cleanup-function-depending-on-derived-computation-value.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: exception) Fixture not implemented

View File

@@ -0,0 +1,21 @@
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component(file: File) {
const [imageUrl, setImageUrl] = useState(null);
/*
* Cleaning up the variable or a source of the variable used to setState
* inside the effect communicates that we always need to clean up something
* which is a valid use case for useEffect. In which case we want to
* avoid an throwing
*/
useEffect(() => {
const imageUrlPrepared = URL.createObjectURL(file);
setImageUrl(imageUrlPrepared);
return () => URL.revokeObjectURL(imageUrlPrepared);
}, [file]);
return <Image src={imageUrl} xstyle={styles.imageSizeLimits} />;
}

View File

@@ -2,7 +2,7 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({propValue}) {
@@ -25,7 +25,7 @@ export const FIXTURE_ENTRYPOINT = {
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component(t0) {
@@ -65,6 +65,12 @@ export const FIXTURE_ENTRYPOINT = {
};
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":12,"column":1,"index":298},"filename":"effect-with-global-function-call-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: exception) globalCall is not defined

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component({propValue}) {

View File

@@ -1,49 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
function Component({value, enabled}) {
const [localValue, setLocalValue] = useState('');
useEffect(() => {
if (enabled) {
setLocalValue(value);
} else {
setLocalValue('disabled');
}
}, [value, enabled]);
return <div>{localValue}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{value: 'test', enabled: true}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props: [value]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.derived-state-conditionally-in-effect.ts:9:6
7 | useEffect(() => {
8 | if (enabled) {
> 9 | setLocalValue(value);
| ^^^^^^^^^^^^^ This should be computed during render, not in an effect
10 | } else {
11 | setLocalValue('disabled');
12 | }
```

View File

@@ -1,46 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
export default function Component({input = 'empty'}) {
const [currInput, setCurrInput] = useState(input);
const localConst = 'local const';
useEffect(() => {
setCurrInput(input + localConst);
}, [input, localConst]);
return <div>{currInput}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{input: 'test'}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props: [input]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.derived-state-from-default-props.ts:9:4
7 |
8 | useEffect(() => {
> 9 | setCurrInput(input + localConst);
| ^^^^^^^^^^^^ This should be computed during render, not in an effect
10 | }, [input, localConst]);
11 |
12 | return <div>{currInput}</div>;
```

View File

@@ -1,43 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
function Component({shouldChange}) {
const [count, setCount] = useState(0);
useEffect(() => {
if (shouldChange) {
setCount(count + 1);
}
}, [count]);
return <div>{count}</div>;
}
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From local state: [count]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.derived-state-from-local-state-in-effect.ts:10:6
8 | useEffect(() => {
9 | if (shouldChange) {
> 10 | setCount(count + 1);
| ^^^^^^^^ This should be computed during render, not in an effect
11 | }
12 | }, [count]);
13 |
```

View File

@@ -1,53 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
function Component({firstName}) {
const [lastName, setLastName] = useState('Doe');
const [fullName, setFullName] = useState('John');
const middleName = 'D.';
useEffect(() => {
setFullName(firstName + ' ' + middleName + ' ' + lastName);
}, [firstName, middleName, lastName]);
return (
<div>
<input value={lastName} onChange={e => setLastName(e.target.value)} />
<div>{fullName}</div>
</div>
);
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{firstName: 'John'}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props and local state: [firstName, lastName]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.derived-state-from-prop-local-state-and-component-scope.ts:11:4
9 |
10 | useEffect(() => {
> 11 | setFullName(firstName + ' ' + middleName + ' ' + lastName);
| ^^^^^^^^^^^ This should be computed during render, not in an effect
12 | }, [firstName, middleName, lastName]);
13 |
14 | return (
```

View File

@@ -1,46 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
function Component({value}) {
const [localValue, setLocalValue] = useState('');
useEffect(() => {
setLocalValue(value);
document.title = `Value: ${value}`;
}, [value]);
return <div>{localValue}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{value: 'test'}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props: [value]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.derived-state-from-prop-with-side-effect.ts:8:4
6 |
7 | useEffect(() => {
> 8 | setLocalValue(value);
| ^^^^^^^^^^^^^ This should be computed during render, not in an effect
9 | document.title = `Value: ${value}`;
10 | }, [value]);
11 |
```

View File

@@ -1,50 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
function Component({propValue}) {
const [value, setValue] = useState(null);
function localFunction() {
console.log('local function');
}
useEffect(() => {
setValue(propValue);
localFunction();
}, [propValue]);
return <div>{value}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{propValue: 'test'}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props: [propValue]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.effect-contains-local-function-call.ts:12:4
10 |
11 | useEffect(() => {
> 12 | setValue(propValue);
| ^^^^^^^^ This should be computed during render, not in an effect
13 | localFunction();
14 | }, [propValue]);
15 |
```

View File

@@ -1,48 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
function Component() {
const [firstName, setFirstName] = useState('Taylor');
const lastName = 'Swift';
// 🔴 Avoid: redundant state and unnecessary Effect
const [fullName, setFullName] = useState('');
useEffect(() => {
setFullName(firstName + ' ' + lastName);
}, [firstName, lastName]);
return <div>{fullName}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From local state: [firstName]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.invalid-derived-computation-in-effect.ts:11:4
9 | const [fullName, setFullName] = useState('');
10 | useEffect(() => {
> 11 | setFullName(firstName + ' ' + lastName);
| ^^^^^^^^^^^ This should be computed during render, not in an effect
12 | }, [firstName, lastName]);
13 |
14 | return <div>{fullName}</div>;
```

View File

@@ -1,46 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
export default function Component(props) {
const [displayValue, setDisplayValue] = useState('');
useEffect(() => {
const computed = props.prefix + props.value + props.suffix;
setDisplayValue(computed);
}, [props.prefix, props.value, props.suffix]);
return <div>{displayValue}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{prefix: '[', value: 'test', suffix: ']'}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props: [props]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.invalid-derived-state-from-computed-props.ts:9:4
7 | useEffect(() => {
8 | const computed = props.prefix + props.value + props.suffix;
> 9 | setDisplayValue(computed);
| ^^^^^^^^^^^^^^^ This should be computed during render, not in an effect
10 | }, [props.prefix, props.value, props.suffix]);
11 |
12 | return <div>{displayValue}</div>;
```

View File

@@ -1,47 +0,0 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
import {useEffect, useState} from 'react';
export default function Component({props}) {
const [fullName, setFullName] = useState(
props.firstName + ' ' + props.lastName
);
useEffect(() => {
setFullName(props.firstName + ' ' + props.lastName);
}, [props.firstName, props.lastName]);
return <div>{fullName}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{props: {firstName: 'John', lastName: 'Doe'}}],
};
```
## Error
```
Found 1 error:
Error: You might not need an effect. Derive values in render, not effects.
Derived values (From props: [props]) should be computed during render, rather than in effects. Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user.
error.invalid-derived-state-from-destructured-props.ts:10:4
8 |
9 | useEffect(() => {
> 10 | setFullName(props.firstName + ' ' + props.lastName);
| ^^^^^^^^^^^ This should be computed during render, not in an effect
11 | }, [props.firstName, props.lastName]);
12 |
13 | return <div>{fullName}</div>;
```

View File

@@ -0,0 +1,80 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component() {
const [firstName, setFirstName] = useState('Taylor');
const lastName = 'Swift';
// 🔴 Avoid: redundant state and unnecessary Effect
const [fullName, setFullName] = useState('');
useEffect(() => {
setFullName(firstName + ' ' + lastName);
}, [firstName, lastName]);
return <div>{fullName}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
function Component() {
const $ = _c(5);
const [firstName] = useState("Taylor");
const [fullName, setFullName] = useState("");
let t0;
let t1;
if ($[0] !== firstName) {
t0 = () => {
setFullName(firstName + " " + "Swift");
};
t1 = [firstName, "Swift"];
$[0] = firstName;
$[1] = t0;
$[2] = t1;
} else {
t0 = $[1];
t1 = $[2];
}
useEffect(t0, t1);
let t2;
if ($[3] !== fullName) {
t2 = <div>{fullName}</div>;
$[3] = fullName;
$[4] = t2;
} else {
t2 = $[4];
}
return t2;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [firstName]\n\nData Flow Tree:\n└── firstName (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":11,"column":4,"index":341},"end":{"line":11,"column":15,"index":352},"filename":"invalid-derived-computation-in-effect.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":0,"index":107},"end":{"line":15,"column":1,"index":445},"filename":"invalid-derived-computation-in-effect.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>Taylor Swift</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
function Component() {

View File

@@ -0,0 +1,79 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
export default function Component(props) {
const [displayValue, setDisplayValue] = useState('');
useEffect(() => {
const computed = props.prefix + props.value + props.suffix;
setDisplayValue(computed);
}, [props.prefix, props.value, props.suffix]);
return <div>{displayValue}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{prefix: '[', value: 'test', suffix: ']'}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
export default function Component(props) {
const $ = _c(7);
const [displayValue, setDisplayValue] = useState("");
let t0;
let t1;
if ($[0] !== props.prefix || $[1] !== props.suffix || $[2] !== props.value) {
t0 = () => {
const computed = props.prefix + props.value + props.suffix;
setDisplayValue(computed);
};
t1 = [props.prefix, props.value, props.suffix];
$[0] = props.prefix;
$[1] = props.suffix;
$[2] = props.value;
$[3] = t0;
$[4] = t1;
} else {
t0 = $[3];
t1 = $[4];
}
useEffect(t0, t1);
let t2;
if ($[5] !== displayValue) {
t2 = <div>{displayValue}</div>;
$[5] = displayValue;
$[6] = t2;
} else {
t2 = $[6];
}
return t2;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ prefix: "[", value: "test", suffix: "]" }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [props]\n\nData Flow Tree:\n└── computed\n └── props (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":9,"column":4,"index":295},"end":{"line":9,"column":19,"index":310},"filename":"invalid-derived-state-from-computed-props.ts","identifierName":"setDisplayValue"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":122},"end":{"line":13,"column":1,"index":409},"filename":"invalid-derived-state-from-computed-props.ts"},"fnName":"Component","memoSlots":7,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>[test]</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
export default function Component(props) {

View File

@@ -0,0 +1,81 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
export default function Component({props}) {
const [fullName, setFullName] = useState(
props.firstName + ' ' + props.lastName
);
useEffect(() => {
setFullName(props.firstName + ' ' + props.lastName);
}, [props.firstName, props.lastName]);
return <div>{fullName}</div>;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{props: {firstName: 'John', lastName: 'Doe'}}],
};
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState } from "react";
export default function Component(t0) {
const $ = _c(6);
const { props } = t0;
const [fullName, setFullName] = useState(
props.firstName + " " + props.lastName,
);
let t1;
let t2;
if ($[0] !== props.firstName || $[1] !== props.lastName) {
t1 = () => {
setFullName(props.firstName + " " + props.lastName);
};
t2 = [props.firstName, props.lastName];
$[0] = props.firstName;
$[1] = props.lastName;
$[2] = t1;
$[3] = t2;
} else {
t1 = $[2];
t2 = $[3];
}
useEffect(t1, t2);
let t3;
if ($[4] !== fullName) {
t3 = <div>{fullName}</div>;
$[4] = fullName;
$[5] = t3;
} else {
t3 = $[5];
}
return t3;
}
export const FIXTURE_ENTRYPOINT = {
fn: Component,
params: [{ props: { firstName: "John", lastName: "Doe" } }],
};
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nProps: [props]\n\nData Flow Tree:\n└── props (Prop)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":10,"column":4,"index":269},"end":{"line":10,"column":15,"index":280},"filename":"invalid-derived-state-from-destructured-props.ts","identifierName":"setFullName"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":122},"end":{"line":14,"column":1,"index":397},"filename":"invalid-derived-state-from-destructured-props.ts"},"fnName":"Component","memoSlots":6,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) <div>John Doe</div>

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState} from 'react';
export default function Component({props}) {

View File

@@ -2,7 +2,7 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState, useRef} from 'react';
export default function Component({test}) {
@@ -31,7 +31,7 @@ export const FIXTURE_ENTRYPOINT = {
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import { useEffect, useState, useRef } from "react";
export default function Component(t0) {
@@ -77,6 +77,12 @@ export const FIXTURE_ENTRYPOINT = {
};
```
## Logs
```
{"kind":"CompileSuccess","fnLoc":{"start":{"line":4,"column":15,"index":130},"end":{"line":18,"column":1,"index":386},"filename":"ref-conditional-in-effect-no-error.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: ok) 8

View File

@@ -1,4 +1,4 @@
// @validateNoDerivedComputationsInEffects_exp
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
import {useEffect, useState, useRef} from 'react';
export default function Component({test}) {

View File

@@ -0,0 +1,72 @@
## Input
```javascript
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
function Component({prop}) {
const [s, setS] = useState();
const [second, setSecond] = useState(prop);
/*
* `second` is a source of state. It will inherit the value of `prop` in
* the first render, but after that it will no longer be updated when
* `prop` changes. So we shouldn't consider `second` as being derived from
* `prop`
*/
useEffect(() => {
setS(second);
}, [second]);
return <div>{s}</div>;
}
```
## Code
```javascript
import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
function Component(t0) {
const $ = _c(5);
const { prop } = t0;
const [s, setS] = useState();
const [second] = useState(prop);
let t1;
let t2;
if ($[0] !== second) {
t1 = () => {
setS(second);
};
t2 = [second];
$[0] = second;
$[1] = t1;
$[2] = t2;
} else {
t1 = $[1];
t2 = $[2];
}
useEffect(t1, t2);
let t3;
if ($[3] !== s) {
t3 = <div>{s}</div>;
$[3] = s;
$[4] = t3;
} else {
t3 = $[4];
}
return t3;
}
```
## Logs
```
{"kind":"CompileError","detail":{"options":{"description":"Using an effect triggers an additional render which can hurt performance and user experience, potentially briefly showing stale values to the user\n\nThis setState call is setting a derived value that depends on the following reactive sources:\n\nState: [second]\n\nData Flow Tree:\n└── second (State)\n\nSee: https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state","category":"EffectDerivationsOfState","reason":"You might not need an effect. Derive values in render, not effects.","details":[{"kind":"error","loc":{"start":{"line":14,"column":4,"index":443},"end":{"line":14,"column":8,"index":447},"filename":"usestate-derived-from-prop-no-show-in-data-flow-tree.ts","identifierName":"setS"},"message":"This should be computed during render, not in an effect"}]}},"fnLoc":null}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":3,"column":0,"index":64},"end":{"line":18,"column":1,"index":500},"filename":"usestate-derived-from-prop-no-show-in-data-flow-tree.ts"},"fnName":"Component","memoSlots":5,"memoBlocks":2,"memoValues":3,"prunedMemoBlocks":0,"prunedMemoValues":0}
```
### Eval output
(kind: exception) Fixture not implemented

View File

@@ -0,0 +1,18 @@
// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
function Component({prop}) {
const [s, setS] = useState();
const [second, setSecond] = useState(prop);
/*
* `second` is a source of state. It will inherit the value of `prop` in
* the first render, but after that it will no longer be updated when
* `prop` changes. So we shouldn't consider `second` as being derived from
* `prop`
*/
useEffect(() => {
setS(second);
}, [second]);
return <div>{s}</div>;
}