Simple function to demonstrate getting test coverage around Javascript code.

reset_form.js

function resetForm() {
  document.getElementById("searchValue").disabled=true;
  document.getElementById("filterValue").disabled=true;
  document.someComplexForm.reset();
}

reset_form_spec.js

describe('Reset Form to Default Values', function() {

  it('returns the form to the way it was when first loaded', function() {
    addTagToHtmlBody('<div id="searchValue"></div>');
    addTagToHtmlBody('<div id="filterValue"></div>');

    document.someComplexForm = new MockComplexForm(); 
    spyOn(document.someComplexForm, 'reset');

    resetForm(); 

    expect(document.getElementById("searchValue").disabled).toBeTruthy(); 
    expect(document.getElementById("filterValue").disabled).toBeTruthy(); 
    expect(document.someComplexForm.reset).toHaveBeenCalled();

    function addTagToHtmlBody(new_tag) {
      $(new_tag).appendTo('body'); 
    }

    function MockComplexForm() { 
      this.reset = function() { /* Does something interesting that is tested elsewhere */ } 
    } 
  });
});