1 files changed, 101 insertions, 0 deletions
diff --git a/remote/webdriver-bidi/modules/Intercept.sys.mjs b/remote/webdriver-bidi/modules/Intercept.sys.mjs
new file mode 100644
index 0000000000..4e3a9bb9e7
--- /dev/null
+++ b/remote/webdriver-bidi/modules/Intercept.sys.mjs
@@ -0,0 +1,101 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  getSeenNodesForBrowsingContext:
+    "chrome://remote/content/shared/webdriver/Session.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+});
+
+/**
+ * The serialization of JavaScript objects in the content process might produce
+ * extra data that needs to be transfered and then processed by the parent
+ * process. This extra data is part of the payload as returned by commands
+ * and events and can contain the following:
+ *
+ *     - {Map<BrowsingContext, Array<string>>} seenNodeIds
+ *         DOM nodes that need to be added to the navigable seen nodes map.
+ *
+ * @param {string} sessionId
+ *     Id of the WebDriver session
+ * @param {object} payload
+ *     Payload of the response for the command and event that might contain
+ *     a `_extraData` field.
+ *
+ * @returns {object}
+ *     The payload with the extra data removed if it was present.
+ */
+export function processExtraData(sessionId, payload) {
+  // Process extra data if present and delete it from the payload
+  if ("_extraData" in payload) {
+    const { seenNodeIds } = payload._extraData;
+
+    // Updates the seen nodes for the current session and browsing context.
+    seenNodeIds?.forEach((nodeIds, browsingContext) => {
+      const seenNodes = lazy.getSeenNodesForBrowsingContext(
+        sessionId,
+        browsingContext
+      );
+
+      nodeIds.forEach(nodeId => seenNodes.add(nodeId));
+    });
+
+    delete payload._extraData;
+  }
+
+  // Find serialized WindowProxy and resolve browsing context to a navigable id.
+  if (payload?.result) {
+    payload.result = addContextIdToSerializedWindow(payload.result);
+  } else if (payload.exceptionDetails) {
+    payload.exceptionDetails = addContextIdToSerializedWindow(
+      payload.exceptionDetails
+    );
+  }
+
+  return payload;
+}
+
+function addContextIdToSerializedWindow(serialized) {
+  if (serialized.value) {
+    switch (serialized.type) {
+      case "array":
+      case "htmlcollection":
+      case "nodelist":
+      case "set": {
+        serialized.value = serialized.value.map(value =>
+          addContextIdToSerializedWindow(value)
+        );
+        break;
+      }
+
+      case "map":
+      case "object": {
+        serialized.value = serialized.value.map(([key, value]) => [
+          key,
+          addContextIdToSerializedWindow(value),
+        ]);
+        break;
+      }
+
+      case "window": {
+        if (serialized.value.isTopBrowsingContext) {
+          const browsingContext = BrowsingContext.getCurrentTopByBrowserId(
+            serialized.value.context
+          );
+
+          serialized.value = {
+            context: lazy.TabManager.getIdForBrowsingContext(browsingContext),
+          };
+        }
+        break;
+      }
+    }
+  } else if (serialized.exception) {
+    serialized.exception = addContextIdToSerializedWindow(serialized.exception);
+  }
+
+  return serialized;
+}