Bug 1694145 - [remote] Add removeSessionData API to RootMessageHandler r=webdriver-reviewers,whimboo

Depends on D132150

Adds a new API to RootMessageHandler which will be necessary to implement _unsubscribeEvent on root/log.jsm
Expand the current browser mochitest for session data to cover the new API.

Differential Revision: https://phabricator.services.mozilla.com/D132152

remote/shared/messagehandler/RootMessageHandler.jsm

@@ -86,33 +86,7 @@ class RootMessageHandler extends MessageHandler {
    * MessageHandlers.
    */
   addSessionData(sessionData = {}) {
-    const { moduleName, category, contextDescriptor, values } = sessionData;
-    const addedValues = this._sessionData.addSessionData(
-      moduleName,
-      category,
-      contextDescriptor,
-      values
-    );
-
-    if (addedValues.length == 0) {
-      // Avoid unnecessary broadcast if no value was added.
-      return [];
-    }
-
-    return this.handleCommand({
-      moduleName,
-      commandName: "_applySessionData",
-      params: {
-        values: addedValues,
-        category,
-      },
-      destination: {
-        type: WindowGlobalMessageHandler.type,
-        contextDescriptor: {
-          type: CONTEXT_DESCRIPTOR_TYPES.ALL,
-        },
-      },
-    });
+    return this._updateSessionData(sessionData, { mode: "add" });
   }
 
   /**
@@ -134,4 +108,57 @@ class RootMessageHandler extends MessageHandler {
         );
     }
   }
+
+  /**
+   * Remove session data items of a given module, category and
+   * contextDescriptor.
+   *
+   * Forwards the call to the SessionData instance owned by this
+   * RootMessageHandler and propagates the information via a command to existing
+   * MessageHandlers.
+   */
+  removeSessionData(sessionData = {}) {
+    return this._updateSessionData(sessionData, { mode: "remove" });
+  }
+
+  _updateSessionData(sessionData, options = {}) {
+    const { mode } = options;
+
+    // TODO: We currently only support adding or removing items separately.
+    // Supporting both will be added with transactions in Bug 1741834.
+    if (mode != "add" && mode != "remove") {
+      throw new Error(`Unsupported mode for _updateSessionData ${mode}`);
+    }
+
+    const { moduleName, category, contextDescriptor, values } = sessionData;
+    const isAdding = mode === "add";
+
+    const updateMethod = isAdding ? "addSessionData" : "removeSessionData";
+    const updatedValues = this._sessionData[updateMethod](
+      moduleName,
+      category,
+      contextDescriptor,
+      values
+    );
+
+    if (updatedValues.length == 0) {
+      // Avoid unnecessary broadcast if no value was removed.
+      return [];
+    }
+
+    return this.handleCommand({
+      moduleName,
+      commandName: "_applySessionData",
+      params: {
+        [isAdding ? "added" : "removed"]: updatedValues,
+        category,
+      },
+      destination: {
+        type: WindowGlobalMessageHandler.type,
+        contextDescriptor: {
+          type: CONTEXT_DESCRIPTOR_TYPES.ALL,
+        },
+      },
+    });
+  }
 }

remote/shared/messagehandler/WindowGlobalMessageHandler.jsm

@@ -89,7 +89,7 @@ class WindowGlobalMessageHandler extends MessageHandler {
             // moduleName & category, but with different values. Instead we can
             // use the fact that _applySessionData supports arrays of values,
             // though it will make the implementation more complex.
-            values: [value],
+            added: [value],
           },
           destination: {
             type: WindowGlobalMessageHandler.type,

remote/shared/messagehandler/sessiondata/SessionData.jsm

@@ -228,6 +228,11 @@ class SessionData {
     return removedValues;
   }
 
+  updateSessionData(moduleName, category, contextDescriptor, added, removed) {
+    this.addSessionData(moduleName, category, contextDescriptor, added);
+    this.removeSessionData(moduleName, category, contextDescriptor, removed);
+  }
+
   _isSameItem(item1, item2) {
     const descriptor1 = item1.contextDescriptor;
     const descriptor2 = item2.contextDescriptor;

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

@@ -17,45 +17,73 @@ add_task(async function test_session_data_broadcast() {
   const root = createRootMessageHandler("session-id-event");
 
   info("Add a new session data item, expect one return value");
-  const value1 = await sendAddSessionData(root, ["text-1"]);
+  const value1 = await addSessionData(root, ["text-1"]);
   is(value1.length, 1);
-  is(value1[0].newData, "text-1");
+  is(value1[0].addedData, "text-1");
+  is(value1[0].removedData, "");
   is(value1[0].sessionData, "text-1");
   is(value1[0].contextId, browsingContext1.id);
 
   info("Add two session data items, expect one return value with both items");
-  const value2 = await sendAddSessionData(root, ["text-2", "text-3"]);
+  const value2 = await addSessionData(root, ["text-2", "text-3"]);
   is(value2.length, 1);
-  is(value2[0].newData, "text-2, text-3");
+  is(value2[0].addedData, "text-2, text-3");
+  is(value2[0].removedData, "");
   is(value2[0].sessionData, "text-1, text-2, text-3");
   is(value2[0].contextId, browsingContext1.id);
 
   info("Try to add an existing data item, expect no return value");
-  const value3 = await sendAddSessionData(root, ["text-1"]);
+  const value3 = await addSessionData(root, ["text-1"]);
   is(value3.length, 0);
 
   info("Add an existing and a new item, expect only the new item to return");
-  const value4 = await sendAddSessionData(root, ["text-1", "text-4"]);
+  const value4 = await addSessionData(root, ["text-1", "text-4"]);
   is(value4.length, 1);
-  is(value4[0].newData, "text-4");
+  is(value4[0].addedData, "text-4");
+  is(value4[0].removedData, "");
   is(value4[0].sessionData, "text-1, text-2, text-3, text-4");
   is(value4[0].contextId, browsingContext1.id);
 
+  info("Remove an item, expect only the new item to return");
+  const value5 = await removeSessionData(root, ["text-3"]);
+  is(value5.length, 1);
+  is(value5[0].addedData, "");
+  is(value5[0].removedData, "text-3");
+  is(value5[0].sessionData, "text-1, text-2, text-4");
+  is(value5[0].contextId, browsingContext1.id);
+
   info("Open a new tab on the same test URL");
   const tab2 = await addTab(TEST_PAGE);
   const browsingContext2 = tab2.linkedBrowser.browsingContext;
 
   info("Add a new session data item, check both contexts have the same data.");
-  const value5 = await sendAddSessionData(root, ["text-5"]);
-  is(value5.length, 2);
-  is(value5[0].newData, "text-5");
-  is(value5[0].sessionData, "text-1, text-2, text-3, text-4, text-5");
-  is(value5[0].contextId, browsingContext1.id);
-  is(value5[1].newData, "text-5");
-  // "text-1, text-2, text-3, text-4" were added as initial session data and
+  const value6 = await addSessionData(root, ["text-5"]);
+  is(value6.length, 2);
+  is(value6[0].addedData, "text-5");
+  is(value6[0].removedData, "");
+  is(value6[0].sessionData, "text-1, text-2, text-4, text-5");
+  is(value6[0].contextId, browsingContext1.id);
+  is(value6[1].addedData, "text-5");
+  // "text-1, text-2, text-4" were added as initial session data and
   // "text-5" was added afterwards.
-  is(value5[1].sessionData, "text-1, text-2, text-3, text-4, text-5");
-  is(value5[1].contextId, browsingContext2.id);
+  is(value6[1].sessionData, "text-1, text-2, text-4, text-5");
+  is(value6[1].contextId, browsingContext2.id);
+
+  info("Remove a missing item, expect no return value");
+  const value7 = await removeSessionData(root, ["text-missing"]);
+  is(value7.length, 0);
+
+  info("Remove an existing and a missing item");
+  const value8 = await removeSessionData(root, ["text-2", "text-missing"]);
+  is(value8.length, 2);
+  is(value8[0].addedData, "");
+  is(value8[0].removedData, "text-2");
+  is(value8[0].sessionData, "text-1, text-4, text-5");
+  is(value8[0].contextId, browsingContext1.id);
+  is(value8[1].addedData, "");
+  is(value8[1].removedData, "text-2");
+  is(value8[1].sessionData, "text-1, text-4, text-5");
+  is(value8[1].contextId, browsingContext2.id);
 
   root.destroy();
 
@@ -63,7 +91,7 @@ add_task(async function test_session_data_broadcast() {
   gBrowser.removeTab(tab2);
 });
 
-function sendAddSessionData(rootMessageHandler, values) {
+function addSessionData(rootMessageHandler, values) {
   return rootMessageHandler.handleCommand({
     moduleName: "command",
     commandName: "testAddSessionData",
@@ -75,3 +103,16 @@ function sendAddSessionData(rootMessageHandler, values) {
     },
   });
 }
+
+function removeSessionData(rootMessageHandler, values) {
+  return rootMessageHandler.handleCommand({
+    moduleName: "command",
+    commandName: "testRemoveSessionData",
+    destination: {
+      type: RootMessageHandler.type,
+    },
+    params: {
+      values,
+    },
+  });
+}

remote/shared/messagehandler/test/browser/resources/modules/root/command.jsm

@@ -32,6 +32,17 @@ class Command extends Module {
     });
   }
 
+  testRemoveSessionData(params) {
+    return this.messageHandler.removeSessionData({
+      moduleName: "command",
+      category: "testCategory",
+      contextDescriptor: {
+        type: CONTEXT_DESCRIPTOR_TYPES.ALL,
+      },
+      values: params.values,
+    });
+  }
+
   testRootModule() {
     return "root-value";
   }

remote/shared/messagehandler/test/browser/resources/modules/windowglobal/command.jsm

@@ -25,11 +25,16 @@ class Command extends Module {
 
   _applySessionData(params) {
     if (params.category === "testCategory") {
-      this._testCategorySessionData = this._testCategorySessionData.concat(
-        params.values
-      );
+      const added = params.added || [];
+      const removed = params.removed || [];
+
+      this._testCategorySessionData = this._testCategorySessionData
+        .concat(added)
+        .filter(value => !removed.includes(value));
+
       return {
-        newData: params.values.join(", "),
+        addedData: added.join(", "),
+        removedData: removed.join(", "),
         sessionData: this._testCategorySessionData.join(", "),
         contextId: this.messageHandler.contextId,
       };