Bug 1810687 - [messagehandler] Group SessionData initial updates by moduleName and category. r=webdriver-reviewers,jdescottes

Differential Revision: https://phabricator.services.mozilla.com/D169312

remote/shared/messagehandler/WindowGlobalMessageHandler.sys.mjs

@@ -72,29 +72,51 @@ export class WindowGlobalMessageHandler extends MessageHandler {
       type: WindowGlobalMessageHandler.type,
     };
 
-    const sessionDataPromises = sessionDataItems.map(sessionDataItem => {
-      const { moduleName, category, contextDescriptor } = sessionDataItem;
+    // Create a Map with the structure moduleName -> category -> relevant session data items.
+    const structuredUpdates = new Map();
+    for (const sessionDataItem of sessionDataItems) {
+      const { category, contextDescriptor, moduleName } = sessionDataItem;
+
       if (!this.matchesContext(contextDescriptor)) {
-        return Promise.resolve();
+        continue;
+      }
+      if (!structuredUpdates.has(moduleName)) {
+        // Skip session data item if the module is not present
+        // for the destination.
+        if (!this.moduleCache.hasModule(moduleName, destination)) {
+          continue;
+        }
+        structuredUpdates.set(moduleName, new Map());
       }
 
-      // Don't apply session data if the module is not present
-      // for the destination.
-      if (!this.moduleCache.hasModule(moduleName, destination)) {
-        return Promise.resolve();
+      if (!structuredUpdates.get(moduleName).has(category)) {
+        structuredUpdates.get(moduleName).set(category, new Set());
       }
 
-      return this.handleCommand({
-        moduleName,
-        commandName: "_applySessionData",
-        params: {
-          category,
-          initial: true,
-          sessionData: sessionDataItems,
-        },
-        destination,
-      });
-    });
+      structuredUpdates
+        .get(moduleName)
+        .get(category)
+        .add(sessionDataItem);
+    }
+
+    const sessionDataPromises = [];
+
+    for (const [moduleName, categories] of structuredUpdates.entries()) {
+      for (const [category, relevantSessionData] of categories.entries()) {
+        sessionDataPromises.push(
+          this.handleCommand({
+            moduleName,
+            commandName: "_applySessionData",
+            params: {
+              category,
+              initial: true,
+              sessionData: Array.from(relevantSessionData),
+            },
+            destination,
+          })
+        );
+      }
+    }
 
     await Promise.all(sessionDataPromises);
 

remote/shared/messagehandler/test/browser/browser_session_data_update_categories.js

@@ -81,5 +81,14 @@ add_task(async function test_session_data_update_categories() {
   assertUpdate(processedUpdates.at(-2), ["value1-2", "value1-3"], "category1");
   assertUpdate(processedUpdates.at(-1), ["value2-1"], "category2");
 
+  info("Opening a new tab triggers an update for each category");
+  const tab2 = await addTab(TEST_PAGE);
+  const browsingContext2 = tab2.linkedBrowser.browsingContext;
+  processedUpdates = await getUpdates(root, browsingContext2);
+  is(processedUpdates.length, 2);
+  assertUpdate(processedUpdates.at(-2), ["value1-2", "value1-3"], "category1");
+  assertUpdate(processedUpdates.at(-1), ["value2-1"], "category2");
+
   root.destroy();
+  gBrowser.removeTab(tab2);
 });

remote/shared/messagehandler/test/browser/browser_session_data_update_contexts.js

@@ -42,10 +42,8 @@ add_task(async function test_session_data_update_contexts() {
   const tab2 = await addTab(TEST_PAGE);
   const browsingContext2 = tab2.linkedBrowser.browsingContext;
 
-  // TODO: We currently call applyInitialSessionDataItems too many times on
-  // MessageHandler startup, once per value. See Bug 1810687.
   processedUpdates = await getUpdates(root, browsingContext2);
-  todo_is(processedUpdates.length, 1);
+  is(processedUpdates.length, 1);
   assertUpdate(
     processedUpdates.at(-1),
     ["text-1", "text-2", "text-3"],
@@ -70,7 +68,7 @@ add_task(async function test_session_data_update_contexts() {
   );
 
   processedUpdates = await getUpdates(root, browsingContext2);
-  todo_is(processedUpdates.length, 2);
+  is(processedUpdates.length, 2);
   assertUpdate(
     processedUpdates.at(-1),
     ["text-1", "text-2", "text-3", "text-4", "text-5"],
@@ -95,7 +93,7 @@ add_task(async function test_session_data_update_contexts() {
   );
 
   processedUpdates = await getUpdates(root, browsingContext2);
-  todo_is(processedUpdates.length, 3);
+  is(processedUpdates.length, 3);
   assertUpdate(
     processedUpdates.at(-1),
     ["text-2", "text-3", "text-4"],
@@ -134,7 +132,7 @@ add_task(async function test_session_data_update_contexts() {
   );
 
   processedUpdates = await getUpdates(root, browsingContext2);
-  todo_is(processedUpdates.length, 4);
+  is(processedUpdates.length, 4);
   assertUpdate(
     processedUpdates.at(-1),
     ["text-2", "text-3", "text-4", "text-6"],
@@ -165,7 +163,7 @@ add_task(async function test_session_data_update_contexts() {
   );
 
   processedUpdates = await getUpdates(root, browsingContext2);
-  todo_is(processedUpdates.length, 5);
+  is(processedUpdates.length, 5);
   assertUpdate(
     processedUpdates.at(-1),
     ["text-2", "text-3", "text-4", "text-6", "text-7"],
@@ -186,7 +184,7 @@ add_task(async function test_session_data_update_contexts() {
   );
 
   processedUpdates = await getUpdates(root, browsingContext2);
-  todo_is(processedUpdates.length, 6);
+  is(processedUpdates.length, 6);
   assertUpdate(
     processedUpdates.at(-1),
     ["text-2", "text-3", "text-4", "text-6"],