[compiler] Prevent innaccurate derivation recording on FunctionExpressions on no-derived-computation-in-effects

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoDerivedComputationsInEffects_exp.ts

@@ -52,6 +52,8 @@ type ValidationContext = {
   readonly setStateUsages: Map<IdentifierId, Set<SourceLocation>>;
 };
 
+const MAX_FIXPOINT_ITERATIONS = 100;
+
 class DerivationCache {
   hasChanges: boolean = false;
   cache: Map<IdentifierId, DerivationMetadata> = new Map();
@@ -224,6 +226,7 @@ export function validateNoDerivedComputationsInEffects_exp(
   }
 
   let isFirstPass = true;
+  let iterationCount = 0;
   do {
     context.derivationCache.takeSnapshot();
 
@@ -236,6 +239,19 @@ export function validateNoDerivedComputationsInEffects_exp(
 
     context.derivationCache.checkForChanges();
     isFirstPass = false;
+    iterationCount++;
+    CompilerError.invariant(iterationCount < MAX_FIXPOINT_ITERATIONS, {
+      reason:
+        '[ValidateNoDerivedComputationsInEffects] Fixpoint iteration failed to converge',
+      description: `Fixpoint iteration exceeded ${MAX_FIXPOINT_ITERATIONS} iterations while tracking derivations. This suggests a cyclic dependency in the derivation cache.`,
+      details: [
+        {
+          kind: 'error',
+          loc: fn.loc,
+          message: `Exceeded ${MAX_FIXPOINT_ITERATIONS} iterations in ValidateNoDerivedComputationsInEffects`,
+        },
+      ],
+    });
   } while (context.derivationCache.snapshot());
 
   for (const [, effect] of effectsCache) {
@@ -422,6 +438,14 @@ function recordInstructionDerivations(
     );
   }
 
+  if (value.kind === 'FunctionExpression') {
+    /*
+     * We don't want to record effect mutations of FunctionExpressions the mutations will happen in the
+     * function body and we will record them there.
+     */
+    return;
+  }
+
   for (const operand of eachInstructionOperand(instr)) {
     switch (operand.effect) {
       case Effect.Capture:
@@ -512,6 +536,19 @@ function buildTreeNode(
 
   const namedSiblings: Set<string> = new Set();
   for (const childId of sourceMetadata.sourcesIds) {
+    CompilerError.invariant(childId !== sourceId, {
+      reason:
+        'Unexpected self-reference: a value should not have itself as a source',
+      description: null,
+      details: [
+        {
+          kind: 'error',
+          loc: sourceMetadata.place.loc,
+          message: null,
+        },
+      ],
+    });
+
     const childNodes = buildTreeNode(
       childId,
       context,

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/function-expression-mutation-edge-case.expect.md

@@ -0,0 +1,115 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
+
+function Component() {
+  const [foo, setFoo] = useState({});
+  const [bar, setBar] = useState(new Set());
+
+  /*
+   * isChanged is considered context of the effect's function expression,
+   * if we don't bail out of effect mutation derivation tracking, isChanged
+   * will inherit the sources of the effect's function expression.
+   *
+   * This is innacurate and with the multiple passes ends up causing an infinite loop.
+   */
+  useEffect(() => {
+    let isChanged = false;
+
+    const newData = foo.map(val => {
+      bar.someMethod(val);
+      isChanged = true;
+    });
+
+    if (isChanged) {
+      setFoo(newData);
+    }
+  }, [foo, bar]);
+
+  return (
+    <div>
+      {foo}, {bar}
+    </div>
+  );
+}
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
+
+function Component() {
+  const $ = _c(9);
+  let t0;
+  if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
+    t0 = {};
+    $[0] = t0;
+  } else {
+    t0 = $[0];
+  }
+  const [foo, setFoo] = useState(t0);
+  let t1;
+  if ($[1] === Symbol.for("react.memo_cache_sentinel")) {
+    t1 = new Set();
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  const [bar] = useState(t1);
+  let t2;
+  let t3;
+  if ($[2] !== bar || $[3] !== foo) {
+    t2 = () => {
+      let isChanged = false;
+
+      const newData = foo.map((val) => {
+        bar.someMethod(val);
+        isChanged = true;
+      });
+
+      if (isChanged) {
+        setFoo(newData);
+      }
+    };
+
+    t3 = [foo, bar];
+    $[2] = bar;
+    $[3] = foo;
+    $[4] = t2;
+    $[5] = t3;
+  } else {
+    t2 = $[4];
+    t3 = $[5];
+  }
+  useEffect(t2, t3);
+  let t4;
+  if ($[6] !== bar || $[7] !== foo) {
+    t4 = (
+      <div>
+        {foo}, {bar}
+      </div>
+    );
+    $[6] = bar;
+    $[7] = foo;
+    $[8] = t4;
+  } else {
+    t4 = $[8];
+  }
+  return t4;
+}
+
+```
+
+## 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: [foo, bar]\n\nData Flow Tree:\n└── newData\n    ├── foo (State)\n    └── bar (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":23,"column":6,"index":663},"end":{"line":23,"column":12,"index":669},"filename":"function-expression-mutation-edge-case.ts","identifierName":"setFoo"},"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":32,"column":1,"index":762},"filename":"function-expression-mutation-edge-case.ts"},"fnName":"Component","memoSlots":9,"memoBlocks":4,"memoValues":5,"prunedMemoBlocks":0,"prunedMemoValues":0}
+```
+      
+### Eval output
+(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/function-expression-mutation-edge-case.js

@@ -0,0 +1,32 @@
+// @validateNoDerivedComputationsInEffects_exp @loggerTestOnly
+
+function Component() {
+  const [foo, setFoo] = useState({});
+  const [bar, setBar] = useState(new Set());
+
+  /*
+   * isChanged is considered context of the effect's function expression,
+   * if we don't bail out of effect mutation derivation tracking, isChanged
+   * will inherit the sources of the effect's function expression.
+   *
+   * This is innacurate and with the multiple passes ends up causing an infinite loop.
+   */
+  useEffect(() => {
+    let isChanged = false;
+
+    const newData = foo.map(val => {
+      bar.someMethod(val);
+      isChanged = true;
+    });
+
+    if (isChanged) {
+      setFoo(newData);
+    }
+  }, [foo, bar]);
+
+  return (
+    <div>
+      {foo}, {bar}
+    </div>
+  );
+}