1 files changed, 62 insertions, 0 deletions
diff --git a/devtools/shared/commands/resource/legacy-listeners/error-messages.js b/devtools/shared/commands/resource/legacy-listeners/error-messages.js
new file mode 100644
index 0000000000..5ba898c917
--- /dev/null
+++ b/devtools/shared/commands/resource/legacy-listeners/error-messages.js
@@ -0,0 +1,62 @@
+/* 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";
+
+const ResourceCommand = require("resource://devtools/shared/commands/resource/resource-command.js");
+const { MESSAGE_CATEGORY } = require("resource://devtools/shared/constants.js");
+
+module.exports = async function ({ targetCommand, targetFront, onAvailable }) {
+  // Allow the top level target unconditionnally.
+  // Also allow frame, but only in content toolbox, i.e. still ignore them in
+  // the context of the browser toolbox as we inspect messages via the process
+  // targets
+  // Also ignore workers as they are not supported yet. (see bug 1592584)
+  const listenForFrames = targetCommand.descriptorFront.isTabDescriptor;
+  const isAllowed =
+    targetFront.isTopLevel ||
+    targetFront.targetType === targetCommand.TYPES.PROCESS ||
+    (targetFront.targetType === targetCommand.TYPES.FRAME && listenForFrames);
+
+  if (!isAllowed) {
+    return;
+  }
+
+  const webConsoleFront = await targetFront.getFront("console");
+  if (webConsoleFront.isDestroyed()) {
+    return;
+  }
+
+  // Request notifying about new messages. Here the "PageError" type start listening for
+  // both actual PageErrors (emitted as "pageError" events) as well as LogMessages (
+  // emitted as "logMessage" events). This function only set up the listener on the
+  // webConsoleFront for "pageError".
+  await webConsoleFront.startListeners(["PageError"]);
+
+  // Fetch already existing messages
+  // /!\ The actor implementation requires to call startListeners("PageError") first /!\
+  let { messages } = await webConsoleFront.getCachedMessages(["PageError"]);
+
+  // On server < v79, we're also getting CSS Messages that we need to filter out.
+  messages = messages.filter(
+    message => message.pageError.category !== MESSAGE_CATEGORY.CSS_PARSER
+  );
+
+  messages.forEach(message => {
+    message.resourceType = ResourceCommand.TYPES.ERROR_MESSAGE;
+  });
+  // Cached messages don't have the same shape as live messages,
+  // so we need to transform them.
+  onAvailable(messages);
+
+  webConsoleFront.on("pageError", message => {
+    // On server < v79, we're getting CSS Messages that we need to filter out.
+    if (message.pageError.category === MESSAGE_CATEGORY.CSS_PARSER) {
+      return;
+    }
+
+    message.resourceType = ResourceCommand.TYPES.ERROR_MESSAGE;
+    onAvailable([message]);
+  });
+};