[compiler] Remove single line constraint and improve overall capturing logic

Author: jorge-cab

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

@@ -34,15 +34,15 @@ export const FIXTURE_ENTRYPOINT = {
 ```
 Found 1 error:
 
-Error: You may not need this effect. Values derived from 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: Derive values in render, not effects.
 
-This effect updates state based on other state values. Consider calculating this value directly during render.
+This setState() appears to derive a value from both props and local state [prefix, name]. Derived values 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.bug-derived-state-from-mixed-deps.ts:9:4
    7 |
    8 |   useEffect(() => {
 >  9 |     setDisplayName(prefix + name);
-     |     ^^^^^^^^^^^^^^ You may not need this effect. Values derived from 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)
+     |     ^^^^^^^^^^^^^^ This should be computed during render, not in an effect
   10 |   }, [prefix, name]);
   11 |
   12 |   return (

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/useEffect/derived-state-with-conditional-no-error.expect.md

@@ -0,0 +1,58 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+import {useState, useEffect} from 'react';
+
+function Component({props, number}) {
+  const nothing = 0;
+  const missDirection = number;
+  const [displayValue, setDisplayValue] = useState(props.prefix + missDirection + nothing);
+
+  useEffect(() => {
+    setDisplayValue(props.prefix + missDirection + nothing);
+  }, [props.prefix, missDirection, nothing]);
+
+  return (
+    <div
+      onClick={() => {
+        setDisplayValue('clicked');
+      }}>
+      {displayValue}
+    </div>
+  );
+}
+
+```
+
+
+## Error
+
+```
+Found 1 error:
+
+Error: Local state shadows parent state.
+
+This setState() appears to derive a value from props [props, number]. This state value shadows a value passed as a prop. Instead of shadowing the prop with local state, hoist the state to the parent component and update it there.
+
+error.derived-state-from-shadowed-props.ts:10:4
+   8 |
+   9 |   useEffect(() => {
+> 10 |     setDisplayValue(props.prefix + missDirection + nothing);
+     |     ^^^^^^^^^^^^^^^ this setState synchronizes the state
+  11 |   }, [props.prefix, missDirection, nothing]);
+  12 |
+  13 |   return (
+
+error.derived-state-from-shadowed-props.ts:16:8
+  14 |     <div
+  15 |       onClick={() => {
+> 16 |         setDisplayValue('clicked');
+     |         ^^^^^^^^^^^^^^^ this setState updates the shadowed state, but should call an onChange event from the parent
+  17 |       }}>
+  18 |       {displayValue}
+  19 |     </div>
+```
+          
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/useEffect/derived-state-with-side-effects-no-error.expect.md

@@ -0,0 +1,21 @@
+// @validateNoDerivedComputationsInEffects
+import {useState, useEffect} from 'react';
+
+function Component({props, number}) {
+  const nothing = 0;
+  const missDirection = number;
+  const [displayValue, setDisplayValue] = useState(props.prefix + missDirection + nothing);
+
+  useEffect(() => {
+    setDisplayValue(props.prefix + missDirection + nothing);
+  }, [props.prefix, missDirection, nothing]);
+
+  return (
+    <div
+      onClick={() => {
+        setDisplayValue('clicked');
+      }}>
+      {displayValue}
+    </div>
+  );
+}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/useEffect/error.bug-derived-state-from-mixed-deps.expect.md

@@ -0,0 +1,49 @@
+
+## 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 1 error:
+
+Error: Derive values in render, not effects.
+
+This setState() appears to derive a value from props [value]. Derived values 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-with-conditional.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 |     }
+```
+          
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/useEffect/error.derived-state-from-shadowed-props.expect.md

@@ -0,0 +1,47 @@
+
+## Input
+
+```javascript
+// @validateNoDerivedComputationsInEffects
+import {useEffect, useState} from 'react';
+
+function Component({value}) {
+  const [localValue, setLocalValue] = useState('');
+
+  useEffect(() => {
+    console.log('Value changed:', value);
+    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: Derive values in render, not effects.
+
+This setState() appears to derive a value from props [value]. Derived values 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-with-side-effects.ts:9:4
+   7 |   useEffect(() => {
+   8 |     console.log('Value changed:', value);
+>  9 |     setLocalValue(value);
+     |     ^^^^^^^^^^^^^ This should be computed during render, not in an effect
+  10 |     document.title = `Value: ${value}`;
+  11 |   }, [value]);
+  12 |
+```
+          
+