fixup! chore(coverage, docs): improve coverage, and add testing documentation

Author: avivkeller

CONTRIBUTING.md

@@ -217,7 +217,7 @@ describe('index.mjs', () => {
     it('should throw for invalid input', () => {
       assert.throws(() => myFunction(undefined), {
         name: 'TypeError',
-        message: 'Input cannot be undefined'
+        message: 'Input cannot be undefined',
       });
     });
   });