1 files changed, 20 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_isModuleLoaded.js b/js/xpconnect/tests/unit/test_isModuleLoaded.js
new file mode 100644
index 0000000000..aaf67c13c7
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_isModuleLoaded.js
@@ -0,0 +1,20 @@
+function run_test() {
+  // Existing module.
+  Assert.ok(!Cu.isModuleLoaded("resource://test/jsm_loaded-1.jsm"),
+            "isModuleLoaded returned correct value for non-loaded module");
+  ChromeUtils.import("resource://test/jsm_loaded-1.jsm");
+  Assert.ok(Cu.isModuleLoaded("resource://test/jsm_loaded-1.jsm"),
+            "isModuleLoaded returned true after loading that module");
+  Cu.unload("resource://test/jsm_loaded-1.jsm");
+  Assert.ok(!Cu.isModuleLoaded("resource://test/jsm_loaded-1.jsm"),
+            "isModuleLoaded returned false after unloading that module");
+
+  // Non-existing module
+  Assert.ok(!Cu.isModuleLoaded("resource://gre/modules/non-existing-module.jsm"),
+            "isModuleLoaded returned correct value for non-loaded module");
+  Assert.throws(
+    () => ChromeUtils.import("resource://gre/modules/non-existing-module.jsm"),
+    /NS_ERROR_FILE_NOT_FOUND/,
+    "Should have thrown while trying to load a non existing file"
+  );
+}