diff --git a/src/lib/util/isDefined.test.ts b/src/lib/util/isDefined.test.ts
new file mode 100644
index 0000000000..ffd732771e
--- /dev/null
+++ b/src/lib/util/isDefined.test.ts
@@ -0,0 +1,8 @@
+import { isDefined } from './isDefined';
+
+test('isDefined', () => {
+    expect(isDefined(null)).toEqual(false);
+    expect(isDefined(undefined)).toEqual(false);
+    expect(isDefined(0)).toEqual(true);
+    expect(isDefined(false)).toEqual(true);
+});
diff --git a/src/lib/util/isDefined.ts b/src/lib/util/isDefined.ts
new file mode 100644
index 0000000000..a9a4a3839a
--- /dev/null
+++ b/src/lib/util/isDefined.ts
@@ -0,0 +1,3 @@
+export const isDefined = <T>(value: T | null | undefined): value is T => {
+    return value !== null && typeof value !== 'undefined';
+};