Tommy Chheng

There’s a niffy trick in browsers that you you execute Javascript code in the url location bar. (This is how a lot of security holes are created too!)
Try typing the below into your browser url bar:

javascript:alert('look how cool this is')

Cool, it runs javascript!

You may have noticed a lot of websites take advantage of this to enhance a service. Instapaper’s “Read Later” saves the current page and Pastefire’s “Pastefire this” saves the selected text.

To make your own, just write javascript inside a link tag as a one liner. Then just ask users to click and drag the link to the bookmark toolbar.

Here’s an example for my Next Sprocket site which will start you on a new open source task with the title and description partially filled out:
Sprocket it!


<a href="javascript:(function(){location.href='http://nextsprocket.com/tasks/new?task[title]='+encodeURIComponent(document.title)+'&task[description]=More details at '+encodeURIComponent(window.location.href)})()">Sprocket it!</a>


I found this great Javascript Lint tool. It checks for common(missing semicolons) and not so common(use of the void type) javascript errors. A full featured Selenium test suite would be the ideal for full javascript testing coverage but Javascript Lint is a no hassle addition.

I wrote a simple Rails integration test case to scan all the javascript files in the public/javascripts folder. Download the javascript lint tool and add the file below to your integration test suite. You easily adapt this to Rspec if you would like.

require 'test_helper'

class JavascriptTest < ActionController::IntegrationTest
  # Download jsl from http://www.javascriptlint.com and add the jsl to your PATH environment variable
  def setup
    @js_paths = File.join(Rails.root, 'public', 'javascripts', '*.js')
  end

  test "validate javascript files for errors" do
    Dir[@js_paths].each do |js_path|
      output = %x[jsl -process #{js_path}]

      is_valid_js_file = output.include?("0 error(s)") ?  true : false
      assert(is_valid_js_file, "JSLint on #{js_path} should return no errors: \n #{output}")
    end
  end
end

Here's an example of the error output:

  2) Failure:
test_validate_javascript_files_for_errors(JavascriptTest)
    [/test/integration/javascript_test.rb:14:in `test_validate_javascript_files_for_errors'
     /test/integration/javascript_test.rb:10:in `each'
     /test/integration/javascript_test.rb:10:in `test_validate_javascript_files_for_errors']:
JSLint on ..../public/javascripts/application.js should return no errors:
 JavaScript Lint 0.3.0 (JavaScript-C 1.5 2004-09-24)
Developed by Matthias Miller (http://www.JavaScriptLint.com)

application.js
.../public/javascripts/application.js(3): lint warning: missing semicolon
        num = ;
........^