2 files changed, 49 insertions, 0 deletions
diff --git a/remote/shared/messagehandler/test/browser/webdriver/browser.ini b/remote/shared/messagehandler/test/browser/webdriver/browser.ini
new file mode 100644
index 0000000000..a7ece66163
--- /dev/null
+++ b/remote/shared/messagehandler/test/browser/webdriver/browser.ini
@@ -0,0 +1,9 @@
+[DEFAULT]
+tags = remote
+subsuite = remote
+support-files =
+  !/remote/shared/messagehandler/test/browser/resources/*
+prefs =
+  remote.messagehandler.modulecache.useBrowserTestRoot=true
+
+[browser_session_execute_command_errors.js]
diff --git a/remote/shared/messagehandler/test/browser/webdriver/browser_session_execute_command_errors.js b/remote/shared/messagehandler/test/browser/webdriver/browser_session_execute_command_errors.js
new file mode 100644
index 0000000000..36a510bb29
--- /dev/null
+++ b/remote/shared/messagehandler/test/browser/webdriver/browser_session_execute_command_errors.js
@@ -0,0 +1,40 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { WebDriverSession } = ChromeUtils.importESModule(
+  "chrome://remote/content/shared/webdriver/Session.sys.mjs"
+);
+
+const { error } = ChromeUtils.importESModule(
+  "chrome://remote/content/shared/webdriver/Errors.sys.mjs"
+);
+
+add_task(async function test_execute_missing_command_error() {
+  const session = new WebDriverSession();
+
+  info("Attempt to execute an unknown protocol command");
+  await Assert.rejects(
+    session.execute("command", "missingCommand"),
+    err =>
+      err.name == "UnknownCommandError" &&
+      err.message == `command.missingCommand`
+  );
+});
+
+add_task(async function test_execute_missing_internal_command_error() {
+  const session = new WebDriverSession();
+
+  info(
+    "Attempt to execute a protocol command which relies on an unknown internal method"
+  );
+  await Assert.rejects(
+    session.execute("command", "testMissingIntermediaryMethod"),
+    err =>
+      err.name == "UnsupportedCommandError" &&
+      err.message ==
+        `command.missingMethod not supported for destination ROOT` &&
+      !error.isWebDriverError(err)
+  );
+});