From 16df0e9d1eafdff543df180a6d66e0ef010d2fba Mon Sep 17 00:00:00 2001
From: Sebastian Markbage <sebastian@calyptus.eu>
Date: Tue, 3 Sep 2024 14:22:21 -0400
Subject: [PATCH] Stash Thenable State on the Dependencies Object for Use By
 DevTools

---
 packages/react-reconciler/src/ReactFiber.js   | 28 +++++++++++++------
 .../react-reconciler/src/ReactFiberHooks.js   | 10 +++++++
 .../src/ReactFiberNewContext.js               | 28 +++++++++++++------
 .../src/ReactInternalTypes.js                 |  3 +-
 4 files changed, 52 insertions(+), 17 deletions(-)

diff --git a/packages/react-reconciler/src/ReactFiber.js b/packages/react-reconciler/src/ReactFiber.js
index db9c4773444e1..4147f0d04e96c 100644
--- a/packages/react-reconciler/src/ReactFiber.js
+++ b/packages/react-reconciler/src/ReactFiber.js
@@ -404,10 +404,16 @@ export function createWorkInProgress(current: Fiber, pendingProps: any): Fiber {
   workInProgress.dependencies =
     currentDependencies === null
       ? null
-      : {
-          lanes: currentDependencies.lanes,
-          firstContext: currentDependencies.firstContext,
-        };
+      : __DEV__
+        ? {
+            lanes: currentDependencies.lanes,
+            firstContext: currentDependencies.firstContext,
+            _debugThenableState: currentDependencies._debugThenableState,
+          }
+        : {
+            lanes: currentDependencies.lanes,
+            firstContext: currentDependencies.firstContext,
+          };
 
   // These will be overridden during the parent's reconciliation
   workInProgress.sibling = current.sibling;
@@ -503,10 +509,16 @@ export function resetWorkInProgress(
     workInProgress.dependencies =
       currentDependencies === null
         ? null
-        : {
-            lanes: currentDependencies.lanes,
-            firstContext: currentDependencies.firstContext,
-          };
+        : __DEV__
+          ? {
+              lanes: currentDependencies.lanes,
+              firstContext: currentDependencies.firstContext,
+              _debugThenableState: currentDependencies._debugThenableState,
+            }
+          : {
+              lanes: currentDependencies.lanes,
+              firstContext: currentDependencies.firstContext,
+            };
 
     if (enableProfilerTimer) {
       // Note: We don't reset the actualTime counts. It's useful to accumulate
diff --git a/packages/react-reconciler/src/ReactFiberHooks.js b/packages/react-reconciler/src/ReactFiberHooks.js
index abe15165203b8..5df344f3a2806 100644
--- a/packages/react-reconciler/src/ReactFiberHooks.js
+++ b/packages/react-reconciler/src/ReactFiberHooks.js
@@ -637,6 +637,16 @@ function finishRenderingHooks<Props, SecondArg>(
 ): void {
   if (__DEV__) {
     workInProgress._debugHookTypes = hookTypesDev;
+    // Stash the thenable state for use by DevTools.
+    if (workInProgress.dependencies === null) {
+      workInProgress.dependencies = {
+        lanes: NoLanes,
+        firstContext: null,
+        _debugThenableState: thenableState,
+      };
+    } else {
+      workInProgress.dependencies._debugThenableState = thenableState;
+    }
   }
 
   // We can assume the previous dispatcher is always this one, since we set it
diff --git a/packages/react-reconciler/src/ReactFiberNewContext.js b/packages/react-reconciler/src/ReactFiberNewContext.js
index 57004e499bc28..bf28da19ce046 100644
--- a/packages/react-reconciler/src/ReactFiberNewContext.js
+++ b/packages/react-reconciler/src/ReactFiberNewContext.js
@@ -825,10 +825,16 @@ function readContextForConsumer_withSelect<C>(
 
       // This is the first dependency for this component. Create a new list.
       lastContextDependency = contextItem;
-      consumer.dependencies = {
-        lanes: NoLanes,
-        firstContext: contextItem,
-      };
+      consumer.dependencies = __DEV__
+        ? {
+            lanes: NoLanes,
+            firstContext: contextItem,
+            _debugThenableState: null,
+          }
+        : {
+            lanes: NoLanes,
+            firstContext: contextItem,
+          };
       if (enableLazyContextPropagation) {
         consumer.flags |= NeedsPropagation;
       }
@@ -869,10 +875,16 @@ function readContextForConsumer<C>(
 
       // This is the first dependency for this component. Create a new list.
       lastContextDependency = contextItem;
-      consumer.dependencies = {
-        lanes: NoLanes,
-        firstContext: contextItem,
-      };
+      consumer.dependencies = __DEV__
+        ? {
+            lanes: NoLanes,
+            firstContext: contextItem,
+            _debugThenableState: null,
+          }
+        : {
+            lanes: NoLanes,
+            firstContext: contextItem,
+          };
       if (enableLazyContextPropagation) {
         consumer.flags |= NeedsPropagation;
       }
diff --git a/packages/react-reconciler/src/ReactInternalTypes.js b/packages/react-reconciler/src/ReactInternalTypes.js
index 4549253ba79b6..871325f379385 100644
--- a/packages/react-reconciler/src/ReactInternalTypes.js
+++ b/packages/react-reconciler/src/ReactInternalTypes.js
@@ -37,6 +37,7 @@ import type {
 } from './ReactFiberTracingMarkerComponent';
 import type {ConcurrentUpdate} from './ReactFiberConcurrentUpdates';
 import type {ComponentStackNode} from 'react-server/src/ReactFizzComponentStack';
+import type {ThenableState} from './ReactFiberThenable';
 
 // Unwind Circular: moved from ReactFiberHooks.old
 export type HookType =
@@ -81,7 +82,7 @@ export type Dependencies = {
     | ContextDependency<mixed>
     | ContextDependencyWithSelect<mixed>
     | null,
-  ...
+  _debugThenableState?: null | ThenableState, // DEV-only
 };
 
 export type MemoCache = {