Repository: facebook/react
Pull request: [DevTools] Add Map for Server Component Logs

Stacked on #30899.

This adds another map to store Server Components logs. When they're replayed with an owner we can associate them with a DevToolsInstance. The replaying should happen before they can mount in Fiber so they'll always have all logs when they mount. There can be more than one Instance associated with any particular ReactComponentInfo. It can also be unmounted and restored later.

One thing that's interesting about these is that when a Server Component tree refreshes a new set of ReactComponentInfo will update through the tree and the VirtualInstances will update with new instances. This means that the old errors/warnings are no longer associated with the VirtualInstance. I.e. it's not continually appended like updates do for Fiber backed instances. On the client we dedupe errors/warnings for the life time of the page. On the server that doesn't work well because it would mean that when you refresh the page, you miss out on warnings so we dedupe them per request instead. If we just appended on refresh it would keep adding them.

If ever add a deduping mechanism that spans longer than a request, we might need to do more of a merge when these updates.

Nothing actually adds logs to this map yet. That will need an integration with Flight in a follow up.

Changed files:
filename: packages/react-devtools-shared/src/backend/fiber/renderer.js
patch: @@ -100,6 +100,9 @@ import {
   SERVER_CONTEXT_SYMBOL_STRING,
 } from '../shared/ReactSymbols';
 import {enableStyleXFeatures} from 'react-devtools-feature-flags';
+
+import {componentInfoToComponentLogsMap} from '../shared/DevToolsServerComponentLogs';
+
 import is from 'shared/objectIs';
 import hasOwnProperty from 'shared/hasOwnProperty';
 
@@ -995,7 +998,8 @@ export function attach(
     // Note, this only clears logs for Fibers that have instances. If they're filtered
     // and then mount, the logs are there. Ensuring we only clear what you've seen.
     // If we wanted to clear the whole set, we'd replace fiberToComponentLogsMap with a
-    // new WeakMap.
+    // new WeakMap. It's unclear whether we should clear componentInfoToComponentLogsMap
+    // since it's shared by other renderers but presumably it would.
 
     // eslint-disable-next-line no-for-of-loops/no-for-of-loops
     for (const devtoolsInstance of idToDevToolsInstanceMap.values()) {
@@ -1006,7 +1010,7 @@ export function attach(
           fiberToComponentLogsMap.delete(fiber.alternate);
         }
       } else {
-        // TODO: Handle VirtualInstance.
+        componentInfoToComponentLogsMap.delete(devtoolsInstance.data);
       }
       const changed = recordConsoleLogs(devtoolsInstance, undefined);
       if (changed) {
@@ -1019,28 +1023,27 @@ export function attach(
   function clearConsoleLogsHelper(instanceID: number, type: 'error' | 'warn') {
     const devtoolsInstance = idToDevToolsInstanceMap.get(instanceID);
     if (devtoolsInstance !== undefined) {
+      let componentLogsEntry;
       if (devtoolsInstance.kind === FIBER_INSTANCE) {
         const fiber = devtoolsInstance.data;
-        const componentLogsEntry = fiberToComponentLogsMap.get(fiber);
-        if (componentLogsEntry !== undefined) {
-          if (type === 'error') {
-            componentLogsEntry.errors.clear();
-            componentLogsEntry.errorsCount = 0;
-          } else {
-            componentLogsEntry.warnings.clear();
-            componentLogsEntry.warningsCount = 0;
-          }
-          const changed = recordConsoleLogs(
-            devtoolsInstance,
-            componentLogsEntry,
-          );
-          if (changed) {
-            flushPendingEvents();
-            updateMostRecentlyInspectedElementIfNecessary(devtoolsInstance.id);
-          }
-        }
+        componentLogsEntry = fiberToComponentLogsMap.get(fiber);
       } else {
-        // TODO: Handle VirtualInstance.
+        const componentInfo = devtoolsInstance.data;
+        componentLogsEntry = componentInfoToComponentLogsMap.get(componentInfo);
+      }
+      if (componentLogsEntry !== undefined) {
+        if (type === 'error') {
+          componentLogsEntry.errors.clear();
+          componentLogsEntry.errorsCount = 0;
+        } else {
+          componentLogsEntry.warnings.clear();
+          componentLogsEntry.warningsCount = 0;
+        }
+        const changed = recordConsoleLogs(devtoolsInstance, componentLogsEntry);
+        if (changed) {
+          flushPendingEvents();
+          updateMostRecentlyInspectedElementIfNecessary(devtoolsInstance.id);
+        }
       }
     }
   }
@@ -2188,6 +2191,10 @@ export function attach(
     pushOperation(ownerID);
     pushOperation(displayNameStringID);
     pushOperation(keyStringID);
+
+    const componentLogsEntry =
+      componentInfoToComponentLogsMap.get(componentInfo);
+    recordConsoleLogs(instance, componentLogsEntry);
   }
 
   function recordUnmount(fiberInstance: FiberInstance): void {
@@ -2857,6 +2864,14 @@ export function attach(
       ) {
         recordResetChildren(virtualInstance);
       }
+      // Update the errors/warnings count. If this Instance has switched to a different
+      // ReactComponentInfo instance, such as when refreshing Server Components, then
+      // we replace all the previous logs with the ones associated with the new ones rather
+      // than merging. Because deduping is expected to happen at the request level.
+      const componentLogsEntry = componentInfoToComponentLogsMap.get(
+        virtualInstance.data,
+      );
+      recordConsoleLogs(virtualInstance, componentLogsEntry);
       // Must be called after all children have been appended.
       recordVirtualProfilingDurations(virtualInstance);
     } finally {
@@ -4293,6 +4308,9 @@ export function attach(
       stylex: null,
     };
 
+    const componentLogsEntry =
+      componentInfoToComponentLogsMap.get(componentInfo);
+
     return {
       id: virtualInstance.id,
 
@@ -4326,8 +4344,14 @@ export function attach(
       hooks: null,
       props: props,
       state: null,
-      errors: [], // TODO: Handle errors on Virtual Instances.
-      warnings: [], // TODO: Handle warnings on Virtual Instances.
+      errors:
+        componentLogsEntry === undefined
+          ? []
+          : Array.from(componentLogsEntry.errors.entries()),
+      warnings:
+        componentLogsEntry === undefined
+          ? []
+          : Array.from(componentLogsEntry.warnings.entries()),
       // List of owners
       owners,
 

filename: packages/react-devtools-shared/src/backend/shared/DevToolsServerComponentLogs.js
patch: @@ -0,0 +1,29 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ */
+
+// This keeps track of Server Component logs which may come from.
+// This is in a shared module because Server Component logs don't come from a specific renderer
+// but can become associated with a Virtual Instance of any renderer.
+
+import type {ReactComponentInfo} from 'shared/ReactTypes';
+
+type ComponentLogs = {
+  errors: Map<string, number>,
+  errorsCount: number,
+  warnings: Map<string, number>,
+  warningsCount: number,
+};
+
+// This keeps it around as long as the ComponentInfo is alive which
+// lets the Fiber get reparented/remounted and still observe the previous errors/warnings.
+// Unless we explicitly clear the logs from a Fiber.
+export const componentInfoToComponentLogsMap: WeakMap<
+  ReactComponentInfo,
+  ComponentLogs,
+> = new WeakMap();