Topic: Hudson

Rails DateTime.to_time, Time, and a case of ‘Why do you need to do that?’

John McCaffrey, Wednesday, September 23, 2009 @ 1:24 pm

The problem: I needed to display a warning to a user if the data they were looking at was more than 90 days old.

The solution: Create a method that takes 2 dates (either DateTime or Time), and returns the number of days, or hours between them.

  def self.difference_in_dates(date1, date2, unit = 1.day)
    return nil if date1.nil? || date2.nil? || unit == 0
      (( date1.to_time - date2.to_time ) / unit).round.abs
  end

The problem was simple enough, and my tests were all passing, so I moved on to my next task.

That code has been out in production for several months, but earlier this week, a new developer told me he got an error when running the test:

  NoMethodError: undefined method `to_f'
    for Mon, 21 Sep 2009 14:29:38 -0500:DateTime

(we're running this in Rails 2.0.2)

I looked at the code, knowing it was working before, ran the unit tests myself, and didn't see the issue. Now I'm on Windows and everyone else is on a mac, so as soon as I run into an issue that no one else has seen I want to prove if its a Windows problem. But wait, this test has been running in our Continuous Integration server (Hudson) for months, and no one else on the team ever had any issues with it, and the code has been working in production without any errors in the logs.

I jumped into rails script/console to see what's up, and here's what I found:

 >> x = DateTime.now
=> Wed, 23 Sep 2009 00:00:00 +0000
>>; x.to_time
=> Wed Sep 23 00:00:00 UTC 2009
>> x.to_time.to_f
=> 1253664000.0

Which is what I expected, but when I asked the other developer to run that same instruction, he got an error.

>> DateTime.now.to_time.to_f
NoMethodError: undefined method `to_f'
  for Mon, 21 Sep 2009 14:29:38 -0500:DateTime

What's up with that? We're running the same code, and all of our libraries are the same version. Looking at the date value in his error, I saw the timezone, and decided to try this variation locally:

>>  x = DateTime.parse("2009-09-21T14:29:38-0500")
=> Mon, 21 Sep 2009 14:29:38 -0500
>> x.to_time.class
=>; DateTime

So I'm gathering that when there is a timezone and you ask DateTime.to_time, its just going to give you back a DateTime.
Continue reading »

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Software Development

Can your Selenium do that? Testing flash/flex and silverlight in web apps with iMacros

John McCaffrey, Wednesday, April 8, 2009 @ 4:00 am

Having learned a long time ago the value of automated testing tools like Selenium, jMeter, and soapUI, I'm always on the lookout for new improvements in these tools. While I love Selenium and other frameworks like it, it has the limitation of not being able to test Flash/Flex/Silverlight or Java Applets. But if you need to test flash and silverlight components of your web app, in an automated way, the  iMacros testing tool might be worth checking out.

No Free Ride

While the free version of the iMacros plugins for InternetExplorer and Firefox allow powerful web scripting similar to Selenium, to be able to do the flash/flex and silverlight, you have to get the paid version or the 30-day trial. I downloaded the trial version to see how it compares to Selenium and what kind of damage I could to.

Going through some of the online demos, Continue reading »

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Software Development

TAE Boston 2008: The Unsexy Presentations

Dietrich Kappe, Wednesday, October 1, 2008 @ 2:07 pm

Lets face it, most people come to Ajax conference for the eye candy. TAE Boston 2008 is no different, and the jQuery, Dojo and other sessions are packed. That's great. I love good eyecandy. But the shame is that many folks skip the less sexy presentations, such as today's presentation by Ted Husted entitle Ajax Testing Tool Review. Talks like these and the tools and methods they discuss is what is leading to the "professionalisation" of front end development, as my colleague Brian Dillard likes to say.

Some of the highlights from Ted's talk:

• If you like CruiseControl, but it's too fiddly for you, you'll love Hudson, a much more user friendly continuous integration engine.
• The Selenium IDE is great for getting started or smoke testing, but use the API's (in Java, C#, Ruby, etc.) to get real, supportable unit tests done.
• YUI Test is intrusive, but it overcomes some of the shortcomings for testing asynchronous events that are present in JsUnit and Selenium. See Ted's post on YUI Test.

OK, not sexy, but if you want to develop quality software, you have to keep an eye on the non-sexy bits.

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Software Development