Don't pass "current" to measureViewTransitionHostInstances

Same thing for cancelViewTransitionHostInstances

This doesn't make sense for "nested" which has not updated and so might not
have an alternate. Instead we pass in the old and new name if they might
be different.

Author: sebmarkbage

packages/react-reconciler/src/ReactFiberCommitViewTransitions.js

@@ -582,21 +582,21 @@ export function restoreNestedViewTransitions(changedParent: Fiber): void {
 }
 
 export function cancelViewTransitionHostInstances(
-  currentViewTransition: Fiber,
   child: null | Fiber,
+  oldName: string,
   stopAtNestedViewTransitions: boolean,
 ): void {
   viewTransitionHostInstanceIdx = 0;
   cancelViewTransitionHostInstancesRecursive(
-    currentViewTransition,
     child,
+    oldName,
     stopAtNestedViewTransitions,
   );
 }
 
 function cancelViewTransitionHostInstancesRecursive(
-  currentViewTransition: Fiber,
   child: null | Fiber,
+  oldName: string,
   stopAtNestedViewTransitions: boolean,
 ): void {
   if (!supportsMutation) {
@@ -605,10 +605,6 @@ function cancelViewTransitionHostInstancesRecursive(
   while (child !== null) {
     if (child.tag === HostComponent) {
       const instance: Instance = child.stateNode;
-      const oldName = getViewTransitionName(
-        currentViewTransition.memoizedProps,
-        currentViewTransition.stateNode,
-      );
       if (viewTransitionCancelableChildren === null) {
         viewTransitionCancelableChildren = [];
       }
@@ -631,8 +627,8 @@ function cancelViewTransitionHostInstancesRecursive(
       // inner most one is the one that handles the update.
     } else {
       cancelViewTransitionHostInstancesRecursive(
-        currentViewTransition,
         child.child,
+        oldName,
         stopAtNestedViewTransitions,
       );
     }
@@ -641,31 +637,31 @@ function cancelViewTransitionHostInstancesRecursive(
 }
 
 export function measureViewTransitionHostInstances(
-  currentViewTransition: Fiber,
   parentViewTransition: Fiber,
   child: null | Fiber,
-  name: string,
+  newName: string,
+  oldName: string,
   className: ?string,
   previousMeasurements: null | Array<InstanceMeasurement>,
   stopAtNestedViewTransitions: boolean,
 ): boolean {
   viewTransitionHostInstanceIdx = 0;
   return measureViewTransitionHostInstancesRecursive(
-    currentViewTransition,
     parentViewTransition,
     child,
-    name,
+    newName,
+    oldName,
     className,
     previousMeasurements,
     stopAtNestedViewTransitions,
   );
 }
 
 function measureViewTransitionHostInstancesRecursive(
-  currentViewTransition: Fiber,
   parentViewTransition: Fiber,
   child: null | Fiber,
-  name: string,
+  newName: string,
+  oldName: string,
   className: ?string,
   previousMeasurements: null | Array<InstanceMeasurement>,
   stopAtNestedViewTransitions: boolean,
@@ -716,10 +712,10 @@ function measureViewTransitionHostInstancesRecursive(
         applyViewTransitionName(
           instance,
           viewTransitionHostInstanceIdx === 0
-            ? name
+            ? newName
             : // If we have multiple Host Instances below, we add a suffix to the name to give
               // each one a unique name.
-              name + '_' + viewTransitionHostInstanceIdx,
+              newName + '_' + viewTransitionHostInstanceIdx,
           className,
         );
       }
@@ -729,10 +725,6 @@ function measureViewTransitionHostInstancesRecursive(
         // animating it. However, in the current model this only works if the parent also
         // doesn't animate. So we have to queue these and wait until we complete the parent
         // to cancel them.
-        const oldName = getViewTransitionName(
-          currentViewTransition.memoizedProps,
-          currentViewTransition.stateNode,
-        );
         if (viewTransitionCancelableChildren === null) {
           viewTransitionCancelableChildren = [];
         }
@@ -759,10 +751,10 @@ function measureViewTransitionHostInstancesRecursive(
     } else {
       if (
         measureViewTransitionHostInstancesRecursive(
-          currentViewTransition,
           parentViewTransition,
           child.child,
-          name,
+          newName,
+          oldName,
           className,
           previousMeasurements,
           stopAtNestedViewTransitions,
@@ -781,6 +773,11 @@ export function measureUpdateViewTransition(
   finishedWork: Fiber,
 ): boolean {
   const props: ViewTransitionProps = finishedWork.memoizedProps;
+  const newName = getViewTransitionName(props, finishedWork.stateNode);
+  const oldName = getViewTransitionName(
+    current.memoizedProps,
+    current.stateNode,
+  );
   const updateClassName: ?string = getViewTransitionClassName(
     props.className,
     props.update,
@@ -807,22 +804,21 @@ export function measureUpdateViewTransition(
     if (layoutClassName === 'none') {
       // If we did not update, then all changes are considered a layout. We'll
       // attempt to cancel.
-      cancelViewTransitionHostInstances(current, finishedWork.child, true);
+      cancelViewTransitionHostInstances(finishedWork.child, oldName, true);
       return false;
     }
     // We didn't update but we might still apply layout so we measure each
     // instance to see if it moved or resized.
     className = layoutClassName;
   }
-  const name = getViewTransitionName(props, finishedWork.stateNode);
   // If nothing changed due to a mutation, or children changing size
   // and the measurements end up unchanged, we should restore it to not animate.
   const previousMeasurements = current.memoizedState;
   const inViewport = measureViewTransitionHostInstances(
-    current,
     finishedWork,
     finishedWork.child,
-    name,
+    newName,
+    oldName,
     className,
     previousMeasurements,
     true,
@@ -842,28 +838,25 @@ export function measureNestedViewTransitions(changedParent: Fiber): void {
   let child = changedParent.child;
   while (child !== null) {
     if (child.tag === ViewTransitionComponent) {
-      const current = child.alternate;
-      if (current !== null) {
-        const props: ViewTransitionProps = child.memoizedProps;
-        const name = getViewTransitionName(props, child.stateNode);
-        const className: ?string = getViewTransitionClassName(
-          props.className,
-          props.layout,
-        );
-        const inViewport = measureViewTransitionHostInstances(
-          current,
-          child,
-          child.child,
-          name,
-          className,
-          child.memoizedState,
-          false,
-        );
-        if ((child.flags & Update) === NoFlags || !inViewport) {
-          // Nothing changed.
-        } else {
-          scheduleViewTransitionEvent(child, props.onLayout);
-        }
+      const props: ViewTransitionProps = child.memoizedProps;
+      const name = getViewTransitionName(props, child.stateNode);
+      const className: ?string = getViewTransitionClassName(
+        props.className,
+        props.layout,
+      );
+      const inViewport = measureViewTransitionHostInstances(
+        child,
+        child.child,
+        name,
+        name, // Since this is unchanged, new and old name is the same.
+        className,
+        child.memoizedState,
+        false,
+      );
+      if ((child.flags & Update) === NoFlags || !inViewport) {
+        // Nothing changed.
+      } else {
+        scheduleViewTransitionEvent(child, props.onLayout);
       }
     } else if ((child.subtreeFlags & ViewTransitionStatic) !== NoFlags) {
       measureNestedViewTransitions(child);