fix: add tests for enums

tests/Multiplicity.spec.ts

@@ -0,0 +1,18 @@
+import { Multiplicity } from '../src/enums/Multiplicity';
+import { expect } from 'chai';
+
+describe('Multiplicity', function () {
+  describe('SingleSelect', function () {
+    it('should return the correct value', function () {
+      const result = Multiplicity.SingleSelect;
+      expect(result).to.equal('SingleSelect');
+    });
+  });
+
+  describe('MultiSelect', function () {
+    it('should return the correct value', function () {
+      const result = Multiplicity.MultiSelect;
+      expect(result).to.equal('MultiSelect');
+    });
+  });
+});