More tests and fixes

test/exceptions.spec.js

@@ -0,0 +1,16 @@
+import {describe, it} from 'mocha';
+import {expect} from 'chai';
+import {ValidationError} from '../src/exceptions';
+
+describe('Exception Tests', () => {
+  it('ValidationException should return message string', () => {
+    expect(
+        new ValidationError(0).message,
+    ).to.equal('0');
+  });
+  it('ValidationException should return errorCode number', () => {
+    expect(
+        new ValidationError(0).errorCode,
+    ).to.equal(0);
+  });
+});