Add tests for boxed strings and Objects pretending to be a string

Author: newtondividedbysqm

test/util.test.js

@@ -54,11 +54,23 @@ describe('assertString', () => {
     assert.throws(() => { assertString([]); }, TypeError);
   });
 
+  it('Should throw an error if argument provided is an Object pretending to be a \'string\'', () => {
+    assert.throws(() => { assertString({constructor: {name: "string"}}); }, TypeError);
+  });
+
+  it('Should throw an error if argument provided is an Object pretending to be a \'String\'', () => {
+    assert.throws(() => { assertString({constructor: {name: "String"}}); }, TypeError);
+  });
+
   it('Should not throw an error if the argument is an empty string', () => {
     assert.doesNotThrow(() => { assertString(''); });
   });
-
+  
   it('Should not throw an error if the argument is a String', () => {
     assert.doesNotThrow(() => { assertString('antidisestablishmentarianism'); });
   });
+
+  it('Should not throw an error if the argument is a boxed string', () => {
+    assert.doesNotThrow(() => { assertString(new String('antidisestablishmentarianism')); });
+  });
 });