[cleanup] fully roll out warnAboutSpreadingKeyToJSX (#26080)

I fully enabled this flag internally now and unless I see complications,
we should be able to clean this up in the code.

packages/react/src/ReactElementValidator.js

@@ -21,7 +21,6 @@ import {
   REACT_FRAGMENT_TYPE,
   REACT_ELEMENT_TYPE,
 } from 'shared/ReactSymbols';
-import {warnAboutSpreadingKeyToJSX} from 'shared/ReactFeatureFlags';
 import checkPropTypes from 'shared/checkPropTypes';
 import isArray from 'shared/isArray';
 
@@ -365,21 +364,18 @@ export function jsxWithValidation(
               Object.freeze(children);
             }
           } else {
-            if (__DEV__) {
             console.error(
               'React.jsx: Static children should always be an array. ' +
                 'You are likely explicitly calling React.jsxs or React.jsxDEV. ' +
                 'Use the Babel transform instead.',
             );
           }
-          }
         } else {
           validateChildKeys(children, type);
         }
       }
     }
 
-    if (warnAboutSpreadingKeyToJSX) {
     if (hasOwnProperty.call(props, 'key')) {
       const componentName = getComponentNameFromType(type);
       const keys = Object.keys(props).filter(k => k !== 'key');
@@ -405,7 +401,6 @@ export function jsxWithValidation(
         didWarnAboutKeySpread[componentName + beforeExample] = true;
       }
     }
-    }
 
     if (type === REACT_FRAGMENT_TYPE) {
       validateFragmentProps(element);

packages/react/src/__tests__/ReactElementJSX-test.js

@@ -264,7 +264,6 @@ describe('ReactElement.jsx', () => {
     );
   });
 
-  if (require('shared/ReactFeatureFlags').warnAboutSpreadingKeyToJSX) {
   it('should warn when keys are passed as part of props', () => {
     const container = document.createElement('div');
     class Child extends React.Component {
@@ -290,7 +289,6 @@ describe('ReactElement.jsx', () => {
         '  <Child key={someKey} {...props} />',
     );
   });
-  }
 
   it('should not warn when unkeyed children are passed to jsxs', () => {
     const container = document.createElement('div');

packages/react/src/jsx/ReactJSXElementValidator.js

@@ -21,7 +21,6 @@ import {
   REACT_FRAGMENT_TYPE,
   REACT_ELEMENT_TYPE,
 } from 'shared/ReactSymbols';
-import {warnAboutSpreadingKeyToJSX} from 'shared/ReactFeatureFlags';
 import hasOwnProperty from 'shared/hasOwnProperty';
 import isArray from 'shared/isArray';
 import {jsxDEV} from './ReactJSXElement';
@@ -390,7 +389,6 @@ export function jsxWithValidation(
       }
     }
 
-    if (warnAboutSpreadingKeyToJSX) {
     if (hasOwnProperty.call(props, 'key')) {
       const componentName = getComponentNameFromType(type);
       const keys = Object.keys(props).filter(k => k !== 'key');
@@ -416,7 +414,6 @@ export function jsxWithValidation(
         didWarnAboutKeySpread[componentName + beforeExample] = true;
       }
     }
-    }
 
     if (type === REACT_FRAGMENT_TYPE) {
       validateFragmentProps(element);

packages/shared/ReactFeatureFlags.js

@@ -185,19 +185,6 @@ export const enableCustomElementPropertySupport = __EXPERIMENTAL__;
 // Disables children for <textarea> elements
 export const disableTextareaChildren = false;
 
-// -----------------------------------------------------------------------------
-// JSX Chopping Block
-//
-// Similar to main Chopping Block but only flags related to JSX. These are
-// grouped because we will likely batch all of them into a single major release.
-// -----------------------------------------------------------------------------
-
-// New API for JSX transforms to target - https://github.com/reactjs/rfcs/pull/107
-
-// Enables a warning when trying to spread a 'key' to an element;
-// a deprecated pattern we want to get rid of in the future
-export const warnAboutSpreadingKeyToJSX = true;
-
 // -----------------------------------------------------------------------------
 // Debugging and DevTools
 // -----------------------------------------------------------------------------

packages/shared/forks/ReactFeatureFlags.native-fb.js

@@ -45,7 +45,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCPUSuspense = true;

packages/shared/forks/ReactFeatureFlags.native-oss.js

@@ -35,7 +35,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCPUSuspense = false;

packages/shared/forks/ReactFeatureFlags.test-renderer.js

@@ -35,7 +35,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCPUSuspense = false;

packages/shared/forks/ReactFeatureFlags.test-renderer.native.js

@@ -35,7 +35,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableComponentStackLocations = false;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;

packages/shared/forks/ReactFeatureFlags.test-renderer.www.js

@@ -35,7 +35,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = false;
 export const disableModulePatternComponents = true;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableSuspenseAvoidThisFallback = true;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCPUSuspense = false;

packages/shared/forks/ReactFeatureFlags.testing.js

@@ -35,7 +35,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = false;
 export const disableModulePatternComponents = false;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableSuspenseAvoidThisFallback = false;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCPUSuspense = false;

packages/shared/forks/ReactFeatureFlags.testing.www.js

@@ -35,7 +35,6 @@ export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const enableTrustedTypesIntegration = false;
 export const disableTextareaChildren = __EXPERIMENTAL__;
 export const disableModulePatternComponents = true;
-export const warnAboutSpreadingKeyToJSX = true;
 export const enableSuspenseAvoidThisFallback = true;
 export const enableSuspenseAvoidThisFallbackFizz = false;
 export const enableCPUSuspense = true;

packages/shared/forks/ReactFeatureFlags.www-dynamic.js

@@ -13,7 +13,6 @@
 // Use __VARIANT__ to simulate a GK. The tests will be run twice: once
 // with the __VARIANT__ set to `true`, and once set to `false`.
 
-export const warnAboutSpreadingKeyToJSX = __VARIANT__;
 export const disableInputAttributeSyncing = __VARIANT__;
 export const enableFilterEmptyStringAttributesDOM = __VARIANT__;
 export const enableLegacyFBSupport = __VARIANT__;

packages/shared/forks/ReactFeatureFlags.www.js

@@ -18,7 +18,6 @@ export const {
   disableInputAttributeSyncing,
   enableTrustedTypesIntegration,
   disableSchedulerTimeoutBasedOnReactExpirationTime,
-  warnAboutSpreadingKeyToJSX,
   replayFailedUnitOfWorkWithInvokeGuardedCallback,
   enableFilterEmptyStringAttributesDOM,
   enableLegacyFBSupport,