Merge pull request #8978 from acdlite/nooptionaltypes

[Fiber] Use `T | null` instead of `?T` types

Author: acdlite

src/renderers/shared/fiber/ReactChildFiber.js

@@ -22,7 +22,7 @@ if (__DEV__) {
 function getCurrentFiberOwnerName() : string | null {
   if (__DEV__) {
     const fiber = ReactDebugCurrentFiber.current;
-    if (fiber == null) {
+    if (fiber === null) {
       return null;
     }
     if (fiber._debugOwner != null) {
@@ -35,7 +35,7 @@ function getCurrentFiberOwnerName() : string | null {
 function getCurrentFiberStackAddendum() : string | null {
   if (__DEV__) {
     const fiber = ReactDebugCurrentFiber.current;
-    if (fiber == null) {
+    if (fiber === null) {
       return null;
     }
     // Safe because if current fiber exists, we are reconciling,

src/renderers/shared/fiber/ReactDebugCurrentFiber.js

@@ -93,11 +93,11 @@ export type Fiber = {
   // This is effectively the parent, but there can be multiple parents (two)
   // so this is only the parent of the thing we're currently processing.
   // It is conceptually the same as the return address of a stack frame.
-  return: ?Fiber,
+  return: Fiber | null,
 
   // Singly Linked List Tree Structure.
-  child: ?Fiber,
-  sibling: ?Fiber,
+  child: Fiber | null,
+  sibling: Fiber | null,
   index: number,
 
   // The ref last used to attach this node.
@@ -119,13 +119,13 @@ export type Fiber = {
   effectTag: TypeOfSideEffect,
 
   // Singly linked list fast path to the next fiber with side-effects.
-  nextEffect: ?Fiber,
+  nextEffect: Fiber | null,
 
   // The first and last fiber with side-effect within this subtree. This allows
   // us to reuse a slice of the linked list when we reuse the work done within
   // this fiber.
-  firstEffect: ?Fiber,
-  lastEffect: ?Fiber,
+  firstEffect: Fiber | null,
+  lastEffect: Fiber | null,
 
   // This will be used to quickly determine if a subtree has no pending changes.
   pendingWorkPriority: PriorityLevel,
@@ -139,19 +139,19 @@ export type Fiber = {
   // priority, then we need to store the progressed work somewhere. This holds
   // the started child set until we need to get back to working on it. It may
   // or may not be the same as the "current" child.
-  progressedChild: ?Fiber,
+  progressedChild: Fiber | null,
 
   // When we reconcile children onto progressedChild it is possible that we have
   // to delete some child fibers. We need to keep track of this side-effects so
   // that if we continue later on, we have to include those effects. Deletions
   // are added in the reverse order from sibling pointers.
-  progressedFirstDeletion: ?Fiber,
-  progressedLastDeletion: ?Fiber,
+  progressedFirstDeletion: Fiber | null,
+  progressedLastDeletion: Fiber | null,
 
   // This is a pooled version of a Fiber. Every fiber that gets updated will
   // eventually have a pair. There are cases when we can clean up pairs to save
   // memory if we need to.
-  alternate: ?Fiber,
+  alternate: Fiber | null,
 
   // Conceptual aliases
   // workInProgress : Fiber ->  alternate The alternate used for reuse happens
@@ -249,7 +249,7 @@ exports.cloneFiber = function(fiber : Fiber, priorityLevel : PriorityLevel) : Fi
   // objects for things that are never updated. It also allow us to reclaim the
   // extra memory if needed.
   let alt = fiber.alternate;
-  if (alt) {
+  if (alt !== null) {
     // If we clone, then we do so from the "current" state. The current state
     // can't have any side-effects that are still valid so we reset just to be
     // sure.

src/renderers/shared/fiber/ReactFiber.js

@@ -102,7 +102,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     // We now have clones. Let's store them as the currently progressed work.
     workInProgress.progressedChild = workInProgress.child;
     workInProgress.progressedPriority = priorityLevel;
-    if (current) {
+    if (current !== null) {
       // We also store it on the current. When the alternate swaps in we can
       // continue from this point.
       current.progressedChild = workInProgress.progressedChild;
@@ -131,7 +131,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     // At this point any memoization is no longer valid since we'll have changed
     // the children.
     workInProgress.memoizedProps = null;
-    if (!current) {
+    if (current === null) {
       // If this is a fresh new component that hasn't been rendered yet, we
       // won't update its child set by applying minimal side-effects. Instead,
       // we will add them all to the child before it gets rendered. That means
@@ -191,9 +191,9 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     return workInProgress.child;
   }
 
-  function markRef(current : ?Fiber, workInProgress : Fiber) {
+  function markRef(current : Fiber | null, workInProgress : Fiber) {
     const ref = workInProgress.ref;
-    if (ref && (!current || current.ref !== ref)) {
+    if (ref !== null && (!current || current.ref !== ref)) {
       // Schedule a Ref effect
       workInProgress.effectTag |= Ref;
     }
@@ -211,7 +211,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
         nextProps = memoizedProps;
       }
     } else {
-      if (nextProps == null || memoizedProps === nextProps) {
+      if (nextProps === null || memoizedProps === nextProps) {
         return bailoutOnAlreadyFinishedWork(current, workInProgress);
       }
       // TODO: Disable this before release, since it is not part of the public API
@@ -240,14 +240,14 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     return workInProgress.child;
   }
 
-  function updateClassComponent(current : ?Fiber, workInProgress : Fiber, priorityLevel : PriorityLevel) {
+  function updateClassComponent(current : Fiber | null, workInProgress : Fiber, priorityLevel : PriorityLevel) {
     // Push context providers early to prevent context stack mismatches.
     // During mounting we don't know the child context yet as the instance doesn't exist.
     // We will invalidate the child context in finishClassComponent() right after rendering.
     const hasContext = pushContextProvider(workInProgress);
 
     let shouldUpdate;
-    if (!current) {
+    if (current === null) {
       if (!workInProgress.stateNode) {
         // In the initial pass we might need to construct the instance.
         constructClassInstance(workInProgress);
@@ -264,7 +264,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
   }
 
   function finishClassComponent(
-    current : ?Fiber,
+    current : Fiber | null,
     workInProgress : Fiber,
     shouldUpdate : boolean,
     hasContext : boolean,
@@ -314,7 +314,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     pushHostContainer(workInProgress, root.containerInfo);
 
     const updateQueue = workInProgress.updateQueue;
-    if (updateQueue) {
+    if (updateQueue !== null) {
       const prevState = workInProgress.memoizedState;
       const state = beginUpdateQueue(workInProgress, updateQueue, null, prevState, null, priorityLevel);
       if (prevState === state) {
@@ -335,7 +335,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     pushHostContext(workInProgress);
 
     let nextProps = workInProgress.pendingProps;
-    const prevProps = current ? current.memoizedProps : null;
+    const prevProps = current !== null ? current.memoizedProps : null;
     const memoizedProps = workInProgress.memoizedProps;
     if (hasContextChanged()) {
       // Normally we can bail out on props equality but if context has changed
@@ -359,7 +359,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
         // that is a bit tricky since workInProgress and current can have
         // different "hidden" settings.
         let child = workInProgress.progressedChild;
-        while (child) {
+        while (child !== null) {
           // To ensure that this subtree gets its priority reset, the children
           // need to be reset.
           child.pendingWorkPriority = OffscreenPriority;
@@ -409,16 +409,16 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
       // Reconcile the children and stash them for later work.
       reconcileChildrenAtPriority(current, workInProgress, nextChildren, OffscreenPriority);
       memoizeProps(workInProgress, nextProps);
-      workInProgress.child = current ? current.child : null;
+      workInProgress.child = current !== null ? current.child : null;
 
-      if (!current) {
+      if (current === null) {
         // If this doesn't have a current we won't track it for placement
         // effects. However, when we come back around to this we have already
         // inserted the parent which means that we'll infact need to make this a
         // placement.
         // TODO: There has to be a better solution to this problem.
         let child = workInProgress.progressedChild;
-        while (child) {
+        while (child !== null) {
           child.effectTag = Placement;
           child = child.sibling;
         }
@@ -464,7 +464,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
       value = fn(props, context);
     }
 
-    if (typeof value === 'object' && value && typeof value.render === 'function') {
+    if (typeof value === 'object' && value !== null && typeof value.render === 'function') {
       // Proceed under the assumption that this is a class instance
       workInProgress.tag = ClassComponent;
 
@@ -479,7 +479,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
       // Proceed under the assumption that this is a functional component
       workInProgress.tag = FunctionalComponent;
       if (__DEV__) {
-        if (workInProgress.ref != null) {
+        if (workInProgress.ref !== null) {
           let info = '';
           const ownerName = ReactDebugCurrentFiber.getCurrentFiberOwnerName();
           if (ownerName) {
@@ -517,7 +517,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
       if (nextCoroutine === null) {
         nextCoroutine = current && current.memoizedProps;
         invariant(
-          nextCoroutine != null,
+          nextCoroutine !== null,
           'We should always have pending or current props. This error is ' +
           'likely caused by a bug in React. Please file an issue.'
         );
@@ -538,7 +538,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     // At this point any memoization is no longer valid since we'll have changed
     // the children.
     workInProgress.memoizedProps = null;
-    if (!current) {
+    if (current === null) {
       workInProgress.stateNode = mountChildFibersInPlace(
         workInProgress,
         workInProgress.stateNode,
@@ -592,7 +592,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
       return bailoutOnAlreadyFinishedWork(current, workInProgress);
     }
 
-    if (!current) {
+    if (current === null) {
       // Portals are special because we don't append the children during mount
       // but at commit. Therefore we need to track insertions which the normal
       // flow doesn't do during mount. This doesn't happen at the root because
@@ -632,7 +632,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
   }
   */
 
-  function bailoutOnAlreadyFinishedWork(current, workInProgress : Fiber) : ?Fiber {
+  function bailoutOnAlreadyFinishedWork(current, workInProgress : Fiber) : Fiber | null {
     const priorityLevel = workInProgress.pendingWorkPriority;
     // TODO: We should ideally be able to bail out early if the children have no
     // more work to do. However, since we don't have a separation of this
@@ -687,7 +687,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     // is handled by beginUpdateQueue.
   }
 
-  function beginWork(current : ?Fiber, workInProgress : Fiber, priorityLevel : PriorityLevel) : ?Fiber {
+  function beginWork(current : Fiber | null, workInProgress : Fiber, priorityLevel : PriorityLevel) : Fiber | null {
     if (workInProgress.pendingWorkPriority === NoWork ||
         workInProgress.pendingWorkPriority > priorityLevel) {
       return bailoutOnLowPriority(current, workInProgress);
@@ -744,7 +744,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
     }
   }
 
-  function beginFailedWork(current : ?Fiber, workInProgress : Fiber, priorityLevel : PriorityLevel) {
+  function beginFailedWork(current : Fiber | null, workInProgress : Fiber, priorityLevel : PriorityLevel) {
     invariant(
       workInProgress.tag === ClassComponent ||
       workInProgress.tag === HostRoot,

src/renderers/shared/fiber/ReactFiberBeginWork.js

@@ -71,7 +71,7 @@ module.exports = function(
   };
 
   function checkShouldComponentUpdate(workInProgress, oldProps, newProps, oldState, newState, newContext) {
-    if (oldProps === null || (workInProgress.updateQueue && workInProgress.updateQueue.hasForceUpdate)) {
+    if (oldProps === null || (workInProgress.updateQueue !== null && workInProgress.updateQueue.hasForceUpdate)) {
       // If the workInProgress already has an Update effect, return true
       return true;
     }
@@ -208,10 +208,10 @@ module.exports = function(
     workInProgress.effectTag |= Update;
   }
 
-  function markUpdateIfAlreadyInProgress(current: ?Fiber, workInProgress : Fiber) {
+  function markUpdateIfAlreadyInProgress(current: Fiber | null, workInProgress : Fiber) {
     // If an update was already in progress, we should schedule an Update
     // effect even though we're bailing out, so that cWU/cDU are called.
-    if (current) {
+    if (current !== null) {
       if (workInProgress.memoizedProps !== current.memoizedProps ||
           workInProgress.memoizedState !== current.memoizedState) {
         markUpdate(workInProgress);
@@ -274,7 +274,7 @@ module.exports = function(
       // If we had additional state updates during this life-cycle, let's
       // process them now.
       const updateQueue = workInProgress.updateQueue;
-      if (updateQueue) {
+      if (updateQueue !== null) {
         instance.state = beginUpdateQueue(
           workInProgress,
           updateQueue,
@@ -343,7 +343,7 @@ module.exports = function(
     // They may be from componentWillMount() or from error boundary's setState()
     // during initial mounting.
     const newUpdateQueue = workInProgress.updateQueue;
-    if (newUpdateQueue) {
+    if (newUpdateQueue !== null) {
       newInstance.state = beginUpdateQueue(
         workInProgress,
         newUpdateQueue,
@@ -392,7 +392,7 @@ module.exports = function(
     const oldState = workInProgress.memoizedState;
     // TODO: Previous state can be null.
     let newState;
-    if (updateQueue) {
+    if (updateQueue !== null) {
       newState = beginUpdateQueue(
         workInProgress,
         updateQueue,
@@ -408,7 +408,7 @@ module.exports = function(
     if (oldProps === newProps &&
         oldState === newState &&
         !hasContextChanged() &&
-        !(updateQueue && updateQueue.hasForceUpdate)) {
+        !(updateQueue !== null && updateQueue.hasForceUpdate)) {
       markUpdateIfAlreadyInProgress(current, workInProgress);
       return false;
     }