Remove no-fallthrough lint suppressions (#26553)

The lint rule already understands a normal comment. Also a bunch of
these were unnecessary.

fixtures/devtools/regression/shared.js

@@ -1,4 +1,4 @@
-/* eslint-disable no-fallthrough, react/react-in-jsx-scope, react/jsx-no-undef */
+/* eslint-disable react/react-in-jsx-scope, react/jsx-no-undef */
 /* global React ReactCache ReactDOM SchedulerTracing ScheduleTracing  */
 
 const apps = [];

packages/react-dom-bindings/src/client/ReactDOMComponent.js

@@ -350,7 +350,6 @@ function setProp(
         }
       }
     // Fall through to the last case which shouldn't remove empty strings.
-    // eslint-disable-next-line no-fallthrough
     case 'formAction': {
       if (
         value == null ||
@@ -663,7 +662,7 @@ function setProp(
       if (enableCustomElementPropertySupport) {
         break;
       }
-    // eslint-disable-next-line no-fallthrough
+    // Fall through
     default: {
       if (
         key.length > 2 &&
@@ -761,7 +760,7 @@ function setPropOnCustomElement(
       if (enableCustomElementPropertySupport) {
         break;
       }
-    // eslint-disable-next-line no-fallthrough
+    // Fall through
     default: {
       if (registrationNameDependencies.hasOwnProperty(key)) {
         if (__DEV__ && value != null && typeof value !== 'function') {
@@ -1010,7 +1009,6 @@ export function setInitialProperties(
       listenToNonDelegatedEvent('load', domElement);
       // We fallthrough to the return of the void elements
     }
-    // eslint-disable-next-line no-fallthrough
     case 'area':
     case 'base':
     case 'br':
@@ -1174,7 +1172,7 @@ export function diffProperties(
               'Cannot update the "is" prop after it has been initialized.',
             );
           }
-        // eslint-disable-next-line no-fallthrough
+        // Fall through
         default: {
           (updatePayload = updatePayload || []).push(propKey, nextProp);
         }
@@ -1790,7 +1788,7 @@ function diffHydratedCustomComponent(
           }
           continue;
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       case 'className':
         if (enableCustomElementPropertySupport) {
           // className is a special cased property on the server to render as an attribute.
@@ -1803,7 +1801,7 @@ function diffHydratedCustomComponent(
           warnForPropDifference('className', serverValue, value);
           continue;
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       default: {
         let ownNamespaceDev = parentNamespaceDev;
         if (ownNamespaceDev === HTML_NAMESPACE) {

packages/react-dom-bindings/src/events/ReactDOMEventListener.js

@@ -319,20 +319,17 @@ export function getEventPriority(domEventName: DOMEventName): EventPriority {
     case 'touchend':
     case 'touchstart':
     case 'volumechange':
-    // Used by polyfills:
-    // eslint-disable-next-line no-fallthrough
+    // Used by polyfills: (fall through)
     case 'change':
     case 'selectionchange':
     case 'textInput':
     case 'compositionstart':
     case 'compositionend':
     case 'compositionupdate':
-    // Only enableCreateEventHandleAPI:
-    // eslint-disable-next-line no-fallthrough
+    // Only enableCreateEventHandleAPI: (fall through)
     case 'beforeblur':
     case 'afterblur':
-    // Not used by React but could be by user code:
-    // eslint-disable-next-line no-fallthrough
+    // Not used by React but could be by user code: (fall through)
     case 'beforeinput':
     case 'blur':
     case 'fullscreenchange':
@@ -357,8 +354,7 @@ export function getEventPriority(domEventName: DOMEventName): EventPriority {
     case 'toggle':
     case 'touchmove':
     case 'wheel':
-    // Not used by React but could be by user code:
-    // eslint-disable-next-line no-fallthrough
+    // Not used by React but could be by user code: (fall through)
     case 'mouseenter':
     case 'mouseleave':
     case 'pointerenter':

packages/react-dom-bindings/src/server/ReactDOMServerFormatConfig.js

@@ -693,7 +693,6 @@ function pushAttribute(
         }
       }
     // Fall through to the last case which shouldn't remove empty strings.
-    // eslint-disable-next-line no-fallthrough
     case 'formAction': {
       if (
         value == null ||
@@ -1123,11 +1122,9 @@ function pushStartOption(
         case 'dangerouslySetInnerHTML':
           innerHTML = propValue;
           break;
-        // eslint-disable-next-line-no-fallthrough
         case 'value':
           value = propValue;
         // We intentionally fallthrough to also set the attribute on the node.
-        // eslint-disable-next-line-no-fallthrough
         default:
           pushAttribute(target, propKey, propValue);
           break;
@@ -1248,7 +1245,6 @@ function pushInput(
             `${'input'} is a self-closing tag and must neither have \`children\` nor ` +
               'use `dangerouslySetInnerHTML`.',
           );
-        // eslint-disable-next-line-no-fallthrough
         case 'defaultChecked':
           defaultChecked = propValue;
           break;
@@ -1330,7 +1326,6 @@ function pushStartTextArea(
           throw new Error(
             '`dangerouslySetInnerHTML` does not make sense on <textarea>.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           pushAttribute(target, propKey, propValue);
           break;
@@ -1677,7 +1672,6 @@ function pushLinkImpl(
             `${'link'} is a self-closing tag and must neither have \`children\` nor ` +
               'use `dangerouslySetInnerHTML`.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           pushAttribute(target, propKey, propValue);
           break;
@@ -1906,7 +1900,6 @@ function pushSelfClosing(
             `${tag} is a self-closing tag and must neither have \`children\` nor ` +
               'use `dangerouslySetInnerHTML`.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           pushAttribute(target, propKey, propValue);
           break;
@@ -1936,7 +1929,6 @@ function pushStartMenuItem(
           throw new Error(
             'menuitems cannot have `children` nor `dangerouslySetInnerHTML`.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           pushAttribute(target, propKey, propValue);
           break;
@@ -2088,7 +2080,6 @@ function pushStartTitle(
           throw new Error(
             '`dangerouslySetInnerHTML` does not make sense on <title>.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           pushAttribute(target, propKey, propValue);
           break;
@@ -2787,11 +2778,12 @@ export function pushEndInstance(
       if (!enableFloat) {
         break;
       }
+      // Fall through
     }
+
     // Omitted close tags
     // TODO: Instead of repeating this switch we could try to pass a flag from above.
     // That would require returning a tuple. Which might be ok if it gets inlined.
-    // eslint-disable-next-line-no-fallthrough
     case 'area':
     case 'base':
     case 'br':
@@ -4044,7 +4036,6 @@ function writeStyleResourceDependencyInJS(
             `${'link'} is a self-closing tag and must neither have \`children\` nor ` +
               'use `dangerouslySetInnerHTML`.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           writeStyleResourceAttributeInJS(destination, propKey, propValue);
           break;
@@ -4240,7 +4231,6 @@ function writeStyleResourceDependencyInAttr(
             `${'link'} is a self-closing tag and must neither have \`children\` nor ` +
               'use `dangerouslySetInnerHTML`.',
           );
-        // eslint-disable-next-line-no-fallthrough
         default:
           writeStyleResourceAttributeInAttr(destination, propKey, propValue);
           break;

packages/react-reconciler/src/ReactFiber.js

@@ -550,29 +550,29 @@ export function createFiberFromTypeAndProps(
         if (enableLegacyHidden) {
           return createFiberFromLegacyHidden(pendingProps, mode, lanes, key);
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       case REACT_SCOPE_TYPE:
         if (enableScopeAPI) {
           return createFiberFromScope(type, pendingProps, mode, lanes, key);
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       case REACT_CACHE_TYPE:
         if (enableCache) {
           return createFiberFromCache(pendingProps, mode, lanes, key);
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       case REACT_TRACING_MARKER_TYPE:
         if (enableTransitionTracing) {
           return createFiberFromTracingMarker(pendingProps, mode, lanes, key);
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       case REACT_DEBUG_TRACING_MODE_TYPE:
         if (enableDebugTracing) {
           fiberTag = Mode;
           mode |= DebugTracingMode;
           break;
         }
-      // eslint-disable-next-line no-fallthrough
+      // Fall through
       default: {
         if (typeof type === 'object' && type !== null) {
           switch (type.$$typeof) {

packages/react-reconciler/src/ReactFiberBeginWork.js

@@ -4096,12 +4096,12 @@ function beginWork(
       if (enableFloat && supportsResources) {
         return updateHostHoistable(current, workInProgress, renderLanes);
       }
-    // eslint-disable-next-line no-fallthrough
+    // Fall through
     case HostSingleton:
       if (enableHostSingletons && supportsSingletons) {
         return updateHostSingleton(current, workInProgress, renderLanes);
       }
-    // eslint-disable-next-line no-fallthrough
+    // Fall through
     case HostComponent:
       return updateHostComponent(current, workInProgress, renderLanes);
     case HostText:

packages/react-reconciler/src/ReactFiberCommitWork.js

@@ -1129,8 +1129,8 @@ function commitLayoutEffectOnFiber(
         }
         break;
       }
+      // Fall through
     }
-    // eslint-disable-next-line-no-fallthrough
     case HostSingleton:
     case HostComponent: {
       recursivelyTraverseLayoutEffects(
@@ -1827,8 +1827,8 @@ function commitPlacement(finishedWork: Fiber): void {
         insertOrAppendPlacementNode(finishedWork, before, parent);
         break;
       }
+      // Fall through
     }
-    // eslint-disable-next-line no-fallthrough
     case HostComponent: {
       const parent: Instance = parentFiber.stateNode;
       if (parentFiber.flags & ContentReset) {
@@ -1851,7 +1851,6 @@ function commitPlacement(finishedWork: Fiber): void {
       insertOrAppendPlacementNodeIntoContainer(finishedWork, before, parent);
       break;
     }
-    // eslint-disable-next-line-no-fallthrough
     default:
       throw new Error(
         'Invalid host parent fiber. This error is likely caused by a bug ' +
@@ -2042,8 +2041,8 @@ function commitDeletionEffectsOnFiber(
         }
         return;
       }
+      // Fall through
     }
-    // eslint-disable-next-line no-fallthrough
     case HostSingleton: {
       if (enableHostSingletons && supportsSingletons) {
         if (!offscreenSubtreeWasHidden) {
@@ -2071,15 +2070,14 @@ function commitDeletionEffectsOnFiber(
 
         return;
       }
+      // Fall through
     }
-    // eslint-disable-next-line no-fallthrough
     case HostComponent: {
       if (!offscreenSubtreeWasHidden) {
         safelyDetachRef(deletedFiber, nearestMountedAncestor);
       }
       // Intentional fallthrough to next branch
     }
-    // eslint-disable-next-line-no-fallthrough
     case HostText: {
       // We only need to remove the nearest host child. Set the host parent
       // to `null` on the stack to indicate that nested children don't
@@ -2707,8 +2705,8 @@ function commitMutationEffectsOnFiber(
         }
         return;
       }
+      // Fall through
     }
-    // eslint-disable-next-line-no-fallthrough
     case HostSingleton: {
       if (enableHostSingletons && supportsSingletons) {
         if (flags & Update) {
@@ -2727,8 +2725,8 @@ function commitMutationEffectsOnFiber(
           }
         }
       }
+      // Fall through
     }
-    // eslint-disable-next-line-no-fallthrough
     case HostComponent: {
       recursivelyTraverseMutationEffects(root, finishedWork, lanes);
       commitReconciliationEffects(finishedWork);
@@ -3772,7 +3770,6 @@ function commitPassiveMountOnFiber(
       }
       // Intentional fallthrough to next branch
     }
-    // eslint-disable-next-line-no-fallthrough
     default: {
       recursivelyTraversePassiveMountEffects(
         finishedRoot,
@@ -3966,7 +3963,6 @@ export function reconnectPassiveEffects(
       }
       // Intentional fallthrough to next branch
     }
-    // eslint-disable-next-line-no-fallthrough
     default: {
       recursivelyTraverseReconnectPassiveEffects(
         finishedRoot,
@@ -4047,7 +4043,6 @@ function commitAtomicPassiveEffects(
       }
       break;
     }
-    // eslint-disable-next-line-no-fallthrough
     default: {
       recursivelyTraverseAtomicPassiveEffects(
         finishedRoot,

packages/react-reconciler/src/ReactFiberCompleteWork.js

@@ -1172,8 +1172,8 @@ function completeWork(
           }
         }
       }
+      // Fall through
     }
-    // eslint-disable-next-line-no-fallthrough
     case HostSingleton: {
       if (enableHostSingletons && supportsSingletons) {
         popHostContext(workInProgress);
@@ -1234,8 +1234,8 @@ function completeWork(
         bubbleProperties(workInProgress);
         return null;
       }
+      // Fall through
     }
-    // eslint-disable-next-line-no-fallthrough
     case HostComponent: {
       popHostContext(workInProgress);
       const type = workInProgress.type;

packages/react-reconciler/src/ReactFiberThrow.js

@@ -465,8 +465,8 @@ function throwException(
             }
             break;
           }
+          // Fall through
         }
-        // eslint-disable-next-line no-fallthrough
         default: {
           throw new Error(
             `Unexpected Suspense handler tag (${suspenseBoundary.tag}). This ` +

packages/react-reconciler/src/ReactFiberWorkLoop.js

@@ -1122,9 +1122,6 @@ function finishConcurrentRender(
     case RootFatalErrored: {
       throw new Error('Root did not complete. This is a bug in React.');
     }
-    // Flow knows about invariant, so it complains if I add a break
-    // statement, but eslint doesn't know about invariant, so it complains
-    // if I do. eslint-disable-next-line no-fallthrough
     case RootErrored: {
       // We should have already attempted to retry this tree. If we reached
       // this point, it errored again. Commit it.
@@ -2381,7 +2378,6 @@ function replaySuspendedUnitOfWork(unitOfWork: Fiber): void {
       unitOfWork.tag = FunctionComponent;
       // Fallthrough to the next branch.
     }
-    // eslint-disable-next-line no-fallthrough
     case SimpleMemoComponent:
     case FunctionComponent: {
       // Resolve `defaultProps`. This logic is copied from `beginWork`.

packages/react-server/src/ReactFizzServer.js

@@ -1224,7 +1224,6 @@ function renderElement(
       }
       throw new Error('ReactDOMServer does not yet support scope components.');
     }
-    // eslint-disable-next-line-no-fallthrough
     case REACT_SUSPENSE_TYPE: {
       if (
         enableSuspenseAvoidThisFallbackFizz &&
@@ -1379,7 +1378,6 @@ function renderNodeDestructiveImpl(
           'Portals are not currently supported by the server renderer. ' +
             'Render them conditionally so that they only appear on the client render.',
         );
-      // eslint-disable-next-line-no-fallthrough
       case REACT_LAZY_TYPE: {
         const lazyNode: LazyComponentType<any, any> = (node: any);
         const payload = lazyNode._payload;

packages/shared/getComponentNameFromType.js

@@ -89,7 +89,7 @@ export default function getComponentNameFromType(type: mixed): string | null {
       if (enableCache) {
         return 'Cache';
       }
-    // eslint-disable-next-line no-fallthrough
+    // Fall through
     case REACT_TRACING_MARKER_TYPE:
       if (enableTransitionTracing) {
         return 'TracingMarker';
@@ -126,7 +126,6 @@ export default function getComponentNameFromType(type: mixed): string | null {
           const context2 = ((type: any): ReactContext<any>);
           return (context2.displayName || context2._globalName) + '.Provider';
         }
-      // eslint-disable-next-line no-fallthrough
     }
   }
   return null;