From e5abb9b9e856cb4e4b948076bc4bc0842c93b5a4 Mon Sep 17 00:00:00 2001
From: Jorge Cabiedes Acosta <jorgecab@meta.com>
Date: Mon, 22 Sep 2025 14:48:02 -0700
Subject: [PATCH] [compiler] ValidateNoDerivedComputationsInEffects test cases

---
 ...rop-setter-call-outside-effect-no-error.js | 23 ++++++
 ...rop-setter-used-outside-effect-no-error.js | 16 ++++
 ...tate-from-ref-and-state-no-error.expect.md | 73 +++++++++++++++++
 ...rived-state-from-ref-and-state-no-error.js | 19 +++++
 ...ains-prop-function-call-no-error.expect.md | 75 +++++++++++++++++
 ...ct-contains-prop-function-call-no-error.js | 17 ++++
 ...fect-with-global-function-call-no-error.js | 17 ++++
 ...ed-state-conditionally-in-effect.expect.md | 58 +++++++++++++
 ...r.derived-state-conditionally-in-effect.js | 21 +++++
 ...derived-state-from-default-props.expect.md | 37 +++++++++
 .../error.derived-state-from-default-props.js | 11 +++
 ...-local-state-and-component-scope.expect.md | 51 ++++++++++++
 ...om-prop-local-state-and-component-scope.js | 25 ++++++
 ...state-from-prop-with-side-effect.expect.md | 43 ++++++++++
 ...erived-state-from-prop-with-side-effect.js | 17 ++++
 ...ror.effect-contains-local-function-call.js | 22 +++++
 ...id-derived-computation-in-effect.expect.md |  0
 ...r.invalid-derived-computation-in-effect.js |  2 +-
 ...erived-state-from-computed-props.expect.md | 44 ++++++++++
 ...valid-derived-state-from-computed-props.js | 18 ++++
 ...ed-state-from-destructured-props.expect.md | 45 ++++++++++
 ...d-derived-state-from-destructured-props.js | 19 +++++
 ...f-conditional-in-effect-no-error.expect.md | 82 +++++++++++++++++++
 .../ref-conditional-in-effect-no-error.js     | 23 ++++++
 24 files changed, 757 insertions(+), 1 deletion(-)
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-call-outside-effect-no-error.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-used-outside-effect-no-error.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-global-function-call-no-error.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.effect-contains-local-function-call.js
 rename compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/{ => effect-derived-computations}/error.invalid-derived-computation-in-effect.expect.md (100%)
 rename compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/{ => effect-derived-computations}/error.invalid-derived-computation-in-effect.js (86%)
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.js
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.js

diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-call-outside-effect-no-error.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-call-outside-effect-no-error.js
new file mode 100644
index 0000000000..fe06b84de2
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-call-outside-effect-no-error.js
@@ -0,0 +1,23 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({initialName}) {
+  const [name, setName] = useState('');
+
+  useEffect(() => {
+    setName(initialName);
+  }, [initialName]);
+
+  return (
+    <div>
+      // 🟡 If the is also called outside of the effect, it's still wrong but
+      should be solved by hoisting state
+      <input value={name} onChange={e => setName(e.target.value)} />
+    </div>
+  );
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{initialName: 'John'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-used-outside-effect-no-error.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-used-outside-effect-no-error.js
new file mode 100644
index 0000000000..c1979819ad
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-prop-setter-used-outside-effect-no-error.js
@@ -0,0 +1,16 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({propValue}) {
+  const [value, setValue] = useState(null);
+  useEffect(() => {
+    setValue(propValue);
+  }, [propValue]);
+
+  return <MockComponent setter={setValue} />;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{propValue: 'test'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.expect.md
new file mode 100644
index 0000000000..1bb5e18626
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.expect.md
@@ -0,0 +1,73 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState, useRef} from 'react';
+
+export default function Component({test}) {
+  const [local, setLocal] = useState('');
+
+  const myRef = useRef(null);
+
+  useEffect(() => {
+    setLocal(myRef.current + test);
+  }, [test]);
+
+  return <>{local}</>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{test: 'testString'}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects
+import { useEffect, useState, useRef } from "react";
+
+export default function Component(t0) {
+  const $ = _c(5);
+  const { test } = t0;
+  const [local, setLocal] = useState("");
+
+  const myRef = useRef(null);
+  let t1;
+  let t2;
+  if ($[0] !== test) {
+    t1 = () => {
+      setLocal(myRef.current + test);
+    };
+    t2 = [test];
+    $[0] = test;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== local) {
+    t3 = <>{local}</>;
+    $[3] = local;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ test: "testString" }],
+};
+
+```
+      
+### Eval output
+(kind: ok) nulltestString
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.js
new file mode 100644
index 0000000000..dec6ae6daa
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/derived-state-from-ref-and-state-no-error.js
@@ -0,0 +1,19 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState, useRef} from 'react';
+
+export default function Component({test}) {
+  const [local, setLocal] = useState('');
+
+  const myRef = useRef(null);
+
+  useEffect(() => {
+    setLocal(myRef.current + test);
+  }, [test]);
+
+  return <>{local}</>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{test: 'testString'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.expect.md
new file mode 100644
index 0000000000..f861d60807
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.expect.md
@@ -0,0 +1,75 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({propValue, onChange}) {
+  const [value, setValue] = useState(null);
+  useEffect(() => {
+    setValue(propValue);
+    onChange();
+  }, [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
+import { useEffect, useState } from "react";
+
+function Component(t0) {
+  const $ = _c(7);
+  const { propValue, onChange } = t0;
+  const [value, setValue] = useState(null);
+  let t1;
+  if ($[0] !== onChange || $[1] !== propValue) {
+    t1 = () => {
+      setValue(propValue);
+      onChange();
+    };
+    $[0] = onChange;
+    $[1] = propValue;
+    $[2] = t1;
+  } else {
+    t1 = $[2];
+  }
+  let t2;
+  if ($[3] !== propValue) {
+    t2 = [propValue];
+    $[3] = propValue;
+    $[4] = t2;
+  } else {
+    t2 = $[4];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[5] !== value) {
+    t3 = <div>{value}</div>;
+    $[5] = value;
+    $[6] = t3;
+  } else {
+    t3 = $[6];
+  }
+  return t3;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ propValue: "test" }],
+};
+
+```
+      
+### Eval output
+(kind: exception) onChange is not a function
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.js
new file mode 100644
index 0000000000..5192feecb1
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-contains-prop-function-call-no-error.js
@@ -0,0 +1,17 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({propValue, onChange}) {
+  const [value, setValue] = useState(null);
+  useEffect(() => {
+    setValue(propValue);
+    onChange();
+  }, [propValue]);
+
+  return <div>{value}</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{propValue: 'test'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-global-function-call-no-error.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-global-function-call-no-error.js
new file mode 100644
index 0000000000..6c10927cc1
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/effect-with-global-function-call-no-error.js
@@ -0,0 +1,17 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({propValue}) {
+  const [value, setValue] = useState(null);
+  useEffect(() => {
+    setValue(propValue);
+    globalCall();
+  }, [propValue]);
+
+  return <div>{value}</div>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{propValue: 'test'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.expect.md
new file mode 100644
index 0000000000..21f1bb974d
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.expect.md
@@ -0,0 +1,58 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+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 2 errors:
+
+Error: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.derived-state-conditionally-in-effect.ts:9:6
+   7 |   useEffect(() => {
+   8 |     if (enabled) {
+>  9 |       setLocalValue(value);
+     |       ^^^^^^^^^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+  10 |     } else {
+  11 |       setLocalValue('disabled');
+  12 |     }
+
+Error: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.derived-state-conditionally-in-effect.ts:11:6
+   9 |       setLocalValue(value);
+  10 |     } else {
+> 11 |       setLocalValue('disabled');
+     |       ^^^^^^^^^^^^^^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+  12 |     }
+  13 |   }, [value, enabled]);
+  14 |
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.js
new file mode 100644
index 0000000000..79d83b8925
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-conditionally-in-effect.js
@@ -0,0 +1,21 @@
+// @validateNoDerivedComputationsInEffects
+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}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.expect.md
new file mode 100644
index 0000000000..964aae40dc
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.expect.md
@@ -0,0 +1,37 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+
+export default function Component(input = 'empty') {
+  const [currInput, setCurrInput] = useState(input);
+
+  useEffect(() => {
+    setCurrInput(input);
+  }, [input]);
+
+  return <div>{currInput}</div>;
+}
+
+```
+
+
+## Error
+
+```
+Found 1 error:
+
+Error: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.derived-state-from-default-props.ts:7:4
+   5 |
+   6 |   useEffect(() => {
+>  7 |     setCurrInput(input);
+     |     ^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+   8 |   }, [input]);
+   9 |
+  10 |   return <div>{currInput}</div>;
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.js
new file mode 100644
index 0000000000..c1ea591316
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-default-props.js
@@ -0,0 +1,11 @@
+// @validateNoDerivedComputationsInEffects
+
+export default function Component(input = 'empty') {
+  const [currInput, setCurrInput] = useState(input);
+
+  useEffect(() => {
+    setCurrInput(input);
+  }, [input]);
+
+  return <div>{currInput}</div>;
+}
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.expect.md
new file mode 100644
index 0000000000..1c994a57ee
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.expect.md
@@ -0,0 +1,51 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({firstName}) {
+  const [lastName, setLastName] = useState(null);
+  const [fullName, setFullName] = useState(null);
+
+  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: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.derived-state-from-prop-local-state-and-component-scope.ts:11:4
+   9 |
+  10 |   useEffect(() => {
+> 11 |     setFullName(firstName + ' ' + middleName + ' ' + lastName);
+     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+  12 |   }, [firstName, middleName, lastName]);
+  13 |
+  14 |   return (
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.js
new file mode 100644
index 0000000000..4b725d5375
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-local-state-and-component-scope.js
@@ -0,0 +1,25 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({firstName}) {
+  const [lastName, setLastName] = useState(null);
+  const [fullName, setFullName] = useState(null);
+
+  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'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.expect.md
new file mode 100644
index 0000000000..fc06bdeb37
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.expect.md
@@ -0,0 +1,43 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+
+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: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.derived-state-from-prop-with-side-effect.ts:7:4
+   5 |
+   6 |   useEffect(() => {
+>  7 |     setLocalValue(value);
+     |     ^^^^^^^^^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+   8 |     document.title = `Value: ${value}`;
+   9 |   }, [value]);
+  10 |
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.js
new file mode 100644
index 0000000000..11c4340eab
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.derived-state-from-prop-with-side-effect.js
@@ -0,0 +1,17 @@
+// @validateNoDerivedComputationsInEffects
+
+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'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.effect-contains-local-function-call.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.effect-contains-local-function-call.js
new file mode 100644
index 0000000000..00e658d896
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.effect-contains-local-function-call.js
@@ -0,0 +1,22 @@
+// @validateNoDerivedComputationsInEffects
+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'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-derived-computation-in-effect.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-computation-in-effect.expect.md
similarity index 100%
rename from compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-derived-computation-in-effect.expect.md
rename to compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-computation-in-effect.expect.md
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-derived-computation-in-effect.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-computation-in-effect.js
similarity index 86%
rename from compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-derived-computation-in-effect.js
rename to compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-computation-in-effect.js
index d803d3c4a3..63d18c9c17 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/error.invalid-derived-computation-in-effect.js
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-computation-in-effect.js
@@ -6,7 +6,7 @@ function BadExample() {
   // 🔴 Avoid: redundant state and unnecessary Effect
   const [fullName, setFullName] = useState('');
   useEffect(() => {
-    setFullName(capitalize(firstName + ' ' + lastName));
+    setFullName(firstName + ' ' + lastName);
   }, [firstName, lastName]);
 
   return <div>{fullName}</div>;
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.expect.md
new file mode 100644
index 0000000000..39d71798aa
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.expect.md
@@ -0,0 +1,44 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+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: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.invalid-derived-state-from-computed-props.ts:9:4
+   7 |   useEffect(() => {
+   8 |     const computed = props.prefix + props.value + props.suffix;
+>  9 |     setDisplayValue(computed);
+     |     ^^^^^^^^^^^^^^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+  10 |   }, [props.prefix, props.value, props.suffix]);
+  11 |
+  12 |   return <div>{displayValue}</div>;
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.js
new file mode 100644
index 0000000000..31fb30cef9
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-computed-props.js
@@ -0,0 +1,18 @@
+// @validateNoDerivedComputationsInEffects
+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: ']'}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.expect.md
new file mode 100644
index 0000000000..7f3f807568
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.expect.md
@@ -0,0 +1,45 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+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: Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+
+error.invalid-derived-state-from-destructured-props.ts:10:4
+   8 |
+   9 |   useEffect(() => {
+> 10 |     setFullName(props.firstName + ' ' + props.lastName);
+     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Values derived from props and state should be calculated during render, not in an effect. (https://react.dev/learn/you-might-not-need-an-effect#updating-state-based-on-props-or-state)
+  11 |   }, [props.firstName, props.lastName]);
+  12 |
+  13 |   return <div>{fullName}</div>;
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.js
new file mode 100644
index 0000000000..2df3df1d52
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/error.invalid-derived-state-from-destructured-props.js
@@ -0,0 +1,19 @@
+// @validateNoDerivedComputationsInEffects
+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'}}],
+};
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.expect.md b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.expect.md
new file mode 100644
index 0000000000..85050d2459
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.expect.md
@@ -0,0 +1,82 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState, useRef} from 'react';
+
+export default function Component({test}) {
+  const [local, setLocal] = useState('');
+
+  const myRef = useRef(null);
+
+  useEffect(() => {
+    if (myRef.current) {
+      setLocal(test + 'Available');
+    } else {
+      setLocal(test + 'NotAvailable');
+    }
+  }, [test]);
+
+  return <>{local}</>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{test: 'testString'}],
+};
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime"; // @validateNoDerivedComputationsInEffects
+import { useEffect, useState, useRef } from "react";
+
+export default function Component(t0) {
+  const $ = _c(5);
+  const { test } = t0;
+  const [local, setLocal] = useState("");
+
+  const myRef = useRef(null);
+  let t1;
+  let t2;
+  if ($[0] !== test) {
+    t1 = () => {
+      if (myRef.current) {
+        setLocal(test + "Available");
+      } else {
+        setLocal(test + "NotAvailable");
+      }
+    };
+
+    t2 = [test];
+    $[0] = test;
+    $[1] = t1;
+    $[2] = t2;
+  } else {
+    t1 = $[1];
+    t2 = $[2];
+  }
+  useEffect(t1, t2);
+  let t3;
+  if ($[3] !== local) {
+    t3 = <>{local}</>;
+    $[3] = local;
+    $[4] = t3;
+  } else {
+    t3 = $[4];
+  }
+  return t3;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{ test: "testString" }],
+};
+
+```
+      
+### Eval output
+(kind: ok) testStringNotAvailable
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.js b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.js
new file mode 100644
index 0000000000..072490988a
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/effect-derived-computations/ref-conditional-in-effect-no-error.js
@@ -0,0 +1,23 @@
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState, useRef} from 'react';
+
+export default function Component({test}) {
+  const [local, setLocal] = useState('');
+
+  const myRef = useRef(null);
+
+  useEffect(() => {
+    if (myRef.current) {
+      setLocal(test + 'Available');
+    } else {
+      setLocal(test + 'NotAvailable');
+    }
+  }, [test]);
+
+  return <>{local}</>;
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Component,
+  params: [{test: 'testString'}],
+};