feat(src/utilities): Add function that asserts that a value is not null or undefined.

src/utilities.ts

@@ -104,3 +104,25 @@ export const getDepositTitle = ({
     return 'Deposit Funds'
   }
 }
+
+/**
+ * Asserts that a value is not null or undefined.
+ *
+ * @param value - The value to check.
+ * @param errorMessage - Optional error message to throw if the assertion fails.
+ * @returns The value itself if it is not null or undefined.
+ * @throws Error if the value is null, undefined, or an empty string.
+ */
+export function assertNotNull<T>(
+  value: T | null | undefined,
+  errorMessage?: string,
+): T {
+  if (
+    value === null ||
+    value === undefined ||
+    (typeof value === 'string' && !value.length)
+  ) {
+    throw new Error(errorMessage ?? 'Assertion failed: value is null')
+  }
+  return value
+}