1 files changed, 143 insertions, 0 deletions
diff --git a/toolkit/components/extensions/child/ext-runtime.js b/toolkit/components/extensions/child/ext-runtime.js
new file mode 100644
index 0000000000..8cf5c445e3
--- /dev/null
+++ b/toolkit/components/extensions/child/ext-runtime.js
@@ -0,0 +1,143 @@
+/* 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/. */
+"use strict";
+
+ChromeUtils.defineESModuleGetters(this, {
+  WebNavigationFrames: "resource://gre/modules/WebNavigationFrames.sys.mjs",
+});
+
+/* eslint-disable jsdoc/check-param-names */
+/**
+ * With optional arguments on both ends, this case is ambiguous:
+ *     runtime.sendMessage("string", {} or nullish)
+ *
+ * Sending a message within the extension is more common than sending
+ * an empty object to another extension, so we prefer that conclusion.
+ *
+ * @param {string?}  [extensionId]
+ * @param {any}      message
+ * @param {object?}  [options]
+ * @param {Function} [callback]
+ * @returns {{extensionId: string?, message: any, callback: Function?}}
+ */
+/* eslint-enable jsdoc/check-param-names */
+function parseBonkersArgs(...args) {
+  let Error = ExtensionUtils.ExtensionError;
+  let callback = typeof args[args.length - 1] === "function" && args.pop();
+
+  // We don't support any options anymore, so only an empty object is valid.
+  function validOptions(v) {
+    return v == null || (typeof v === "object" && !Object.keys(v).length);
+  }
+
+  if (args.length === 1 || (args.length === 2 && validOptions(args[1]))) {
+    // Interpret as passing null for extensionId (message within extension).
+    args.unshift(null);
+  }
+  let [extensionId, message, options] = args;
+
+  if (!args.length) {
+    throw new Error("runtime.sendMessage's message argument is missing");
+  } else if (!validOptions(options)) {
+    throw new Error("runtime.sendMessage's options argument is invalid");
+  } else if (args.length === 4 && args[3] && !callback) {
+    throw new Error("runtime.sendMessage's last argument is not a function");
+  } else if (args[3] != null || args.length > 4) {
+    throw new Error("runtime.sendMessage received too many arguments");
+  } else if (extensionId && typeof extensionId !== "string") {
+    throw new Error("runtime.sendMessage's extensionId argument is invalid");
+  }
+  return { extensionId, message, callback };
+}
+
+this.runtime = class extends ExtensionAPI {
+  getAPI(context) {
+    let { extension } = context;
+
+    return {
+      runtime: {
+        onConnect: context.messenger.onConnect.api(),
+        onMessage: context.messenger.onMessage.api(),
+
+        onConnectExternal: context.messenger.onConnectEx.api(),
+        onMessageExternal: context.messenger.onMessageEx.api(),
+
+        connect(extensionId, options) {
+          let name = options?.name ?? "";
+          return context.messenger.connect({ name, extensionId });
+        },
+
+        sendMessage(...args) {
+          let arg = parseBonkersArgs(...args);
+          return context.messenger.sendRuntimeMessage(arg);
+        },
+
+        connectNative(name) {
+          return context.messenger.connect({ name, native: true });
+        },
+
+        sendNativeMessage(nativeApp, message) {
+          return context.messenger.sendNativeMessage(nativeApp, message);
+        },
+
+        get lastError() {
+          return context.lastError;
+        },
+
+        getManifest() {
+          return Cu.cloneInto(extension.manifest, context.cloneScope);
+        },
+
+        id: extension.id,
+
+        getURL(url) {
+          return extension.baseURI.resolve(url);
+        },
+
+        getFrameId(target) {
+          let frameId = WebNavigationFrames.getFromWindow(target);
+          if (frameId >= 0) {
+            return frameId;
+          }
+          // Not a WindowProxy, perhaps an embedder element?
+
+          let type;
+          try {
+            type = Cu.getClassName(target, true);
+          } catch (e) {
+            // Not a valid object, will throw below.
+          }
+
+          const embedderTypes = [
+            "HTMLIFrameElement",
+            "HTMLFrameElement",
+            "HTMLEmbedElement",
+            "HTMLObjectElement",
+          ];
+
+          if (embedderTypes.includes(type)) {
+            if (!target.browsingContext) {
+              return -1;
+            }
+            return WebNavigationFrames.getFrameId(target.browsingContext);
+          }
+
+          throw new ExtensionUtils.ExtensionError("Invalid argument");
+        },
+      },
+    };
+  }
+
+  getAPIObjectForRequest(context, request) {
+    if (request.apiObjectType === "Port") {
+      const port = context.messenger.getPortById(request.apiObjectId);
+      if (!port) {
+        throw new Error(`Port API object not found: ${request}`);
+      }
+      return port.api;
+    }
+
+    throw new Error(`Unexpected apiObjectType: ${request}`);
+  }
+};