1 files changed, 8 insertions, 0 deletions
diff --git a/client/simple/src/js/util/assertElement.ts b/client/simple/src/js/util/assertElement.ts
new file mode 100644
index 000000000..a362fcf8f
--- /dev/null
+++ b/client/simple/src/js/util/assertElement.ts
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+type AssertElement = <T>(element?: T | null) => asserts element is T;
+export const assertElement: AssertElement = <T>(element?: T | null): asserts element is T => {
+  if (!element) {
+    throw new Error("DOM element not found");
+  }
+};