Skip to main content

Posts

Showing posts from 2012

What to test when testing Javascript

Part two in the series Test Driven Development with Javascript.



By now you've probably read and heard a lot warning you off testing through the UI and testing the user interface generally. Those still holds true for Javascript so you may be wondering if there is anything left to test. Time for some code!

Not very testable code

function validate() {
    if(document.simple_form.name.value == "" ||
        document.simple_form.email.value == "")
    {
        alert("Please fill out all fields before clicking submit!");
        return false;
    }
}

In this there is some logic that is not directly tied to the UI. So there is something we can test. But it’ll need a bit of a rework to make it testable

function isFormValid(formElement) {
    return (formElement.name.value != "" && formElement.email.value != "");
}

function validate() {
    if (!isFormValid(document.simple_form)) {
        alert("Please fill out all fields before clicking subm…

Test Driven Development with Javascript

I've had a few opportunities to put my TDD skills to use in this brave new frontier. So I wanted to share what I've learned, what pitfalls to avoid and where the low hanging fruit is.

Why use TDD in Javascript?
We've reached a point where few people can develop an application without there being a web interface included. And now it's not enough to build a website with a few forms and buttons it has to be a "web application" with the detailed user interface and responsiveness we would expect of a desktop application. Javascript is serious business. Clients are not going to compliment you on your stable and fully tested backend if the UI is painful.

When should you not use TDD in Javascript?
Javascript has a strange distinction. It is the most widely used programming language in the world. It is also the most disliked programming language in the world. It can be hard to get programmers to learn Javascript before they dive into writing Javascript. So you cannot expe…

RestFixture

So most of the tests I'm writing now in Fitnesse are using RestFixture. Being able to do all this black box style testing has helped me get a lot of tests up and running without having to change the existing code base. Now I've taken a step future with my own little fork so I can use scenarios and build nice BDD style scripts. But first I want to give me own quick guide to using RestFixture

Step 1: Installing
You can dive straight in by grabbing the latest jar files for RestFixture here https://github.com/smartrics/RestFixture/downloads
If you know what you're doing can get the nodep version to work nicely along side other libraries you may be including in Fitnesse. But I grabbed the 'full' version and unzipped it into a RestFixture folder alongside my FitNesseRoot folder.
Step 2: Write your first test
I took advantage of the built in Fitnesse api as a basic test and wrote a page called RestFixture with the following contents
!define TEST_SYSTEM {slim} !path RestFix…

JDBC Fixture

I created this class so I can run basic database commands from within Fitnesse. Dropping SQL into a Fitnesse page not recommended but it can still be a useful tool for a few reasons: It is reusable so you can drop it into lots of tests without making new classes all the timeIt's a good bridging tool in trying to get developers using fitnesse who are not used to creating an abstraction layer for their testsIt's handy to combine with RestFixture when you need to adjust or validate the data but cannot do it through a rest command But again it's not recommended. Better to create a new fixture with a function like public void createNewUser(String name, String password)

Here is what running the JDBCFixture looks like in the fitnesse !path lib/*.jar !|import | |com.warmage.util.fixtures| !|script|DBQueryFixture|mydatabase |user |pass | |check |statement |UPDATE users SET city='New York' WHERE…

Skipping over fitnesse tutorial

I was thinking of writing a short bit on writing tests in Fitnesse. But instead I'm going to recommend the tutorials by Brett L. Schuchert http://schuchert.wikispaces.com/FitNesse.Tutorials as they skip straight into using SLIM. The guides on fitnesse.org (and with the install) are good but explain everything with FIT first before racing though what is different with SLIM. That's just the nature of how Fitnesse was developed but it's worth skipping straight to SLIM as it has less requirements and can be more flexable.

Setting up Fitnesse on Ubuntu in 7 steps

Some pretty basic steps but just to make sure it's here for everyone to see. Setting up fitnesse and running the jar is easy enough. Just go to http://fitnesse.org/ and get started and do it on your desktop just to see it in action. But for me that wasn't good enough I wanted it to run as service on ubuntu.

I stole a few tricks from how ubuntu runs jenkins and setup fitnesse a similar way.

1. Create a user and group for fitnesse (optional)
I didn't do this because I wanted tomcat, jenkins and fitnesse all running as the same user. Call it laziness to avoid any permissions classing but it doesn't change the process that you need to create or choose what user you're going to make it run as. Don't make it run as your user or root!

2. Download the jar file and place it in /usr/share/fitnesse
Make the folder too of course. It can belong to root as long as the fitnesse user has read access

3. Create the folder to run in at /var/lib/fitnesse
Fitnesse user needs write…

Fitnesse

Anyone who has worked with me in the last 3 years knows I have a programmer crush on Uncle Bob and I got most of my initial training on Agile development from James Grenning. So it was just a matter of time until I started using Fitnesse. Now fitnesse (and fit originally) is an interesting tool to try and get acceptance tests OUT of code. After all why should programmers (or programmer-ish testers) be the only ones to write, read and review these tests? Acceptance testing is about making sure you deliver what the customer wanted so shouldn't the customer and other management people be reading them too? So fitnesse meets them in a middle ground. A wiki.

A wiki is a good place to go because you can get a manager or customer to read a wiki. You can, with a bit of a push, even get them to start contributing to a wiki. Good luck trying to get them using jmeter or read what you created in cucumber! Those are great tools but they don't scratch the itch that fitnesse was written for.…

Test value is in running them

Have you seen a build flag that states "no tests". What's the point building code without running all your tests? What's the harm in running them one last time? Tests are there to be run. A LOT! Settings that allow you to run tests every time you save a file in your IDE help ensure your unit tests are fast and passing all the time. Unit tests are there to catch you when you break something unexpected. You may think your fixing a bug with a date-time object but maybe that fix breaks something else down the line. The tests are there to tell you. If you never run your tests then why bother having them? Why not just delete them all?

When should tests be run?

As often as possible. Especially fast unit testsEvery time you buildBefore committing changes to production code to version controlBefore  committing changes to test code to version controlAfter committing code to version control (via Continuous Integration)

Bad Programmer Habits

Do you do any of these? Do you see these habits in others. Clean code is when you look at code and think "of course you would do it that way". It's simple, elegant, and straight forward. Once you look at it you can't think of a better way to do it. It seems 'obvious' but only with the power of hindsight. But it's not something you'll get much of from these programmers
The Hoarder - "I’ll add/leave this function because it may come in useful" litters your code with commented code and unused functions that rot and bloat your codeOver-Complicator - "I've built an xml like nested config value loader to read in my three values instead of using a constant" yeah thanks. And when it turns out to have a bug we'll spend weeks trying to figure out how it all works and why you wasted company time (and money) writing it.Rewriter - "This 3D library doesn't quite fit my needs. I think I'll write my own and call it DirectY"…

Grumpy programmers

Have you ever had to work with that guy. The one who hates going to meetings. Ridicules the other developers. Sits by themselves rarely talking with anyone while "working". Sometimes they swear a lot, sometimes they often show up late to work and often they have little interest in showing someone else how their code works.

Have I been that guy? Honestly I can't say for sure I never have been. My programming idol Uncle Bob admits to being that guy once in his book Clean Coder.

There's a lot of old stereotypes around programming and computers in general. I've been told once to put up with a grumpy programmer on the promise he would work twice as fast as any other (if not faster). Turned out he was pretty clever but he wasn't any faster than the average for the team. And when he got really grumpy he got sloppy and produced some of the worst programming I've ever seen. So I've since resolved to never endure such behaviour and that any anti-social behaviou…

TDD is good for you. But it's a hard habit to form

I've been thinking a lot about TDD, agile training and the long term behaviour of teams after such training. I've met far more programmers who have had training in TDD than I know programmers who practice TDD. And I've heard all the excusesYou can't do TDD with this languageYou can't do TDD with this frameworkYou can't do TDD with this databaseYou can't do TDD with this hardwareYou can't do TDD with this scheduleAll bullshit, believe me. I may have said some of those myself onceBut once you get past all that you get programmers who will give you a lucid agreement that TDD is good and they should use it more. You train them and show them how it's done as well as push past the issues above.And then they don't use it.But why? They agreed it's a good idea and they should do more. We solved all the serious issues that were stopping them from trying. Why wont they even try and put it into their routine?Routine. That's part of the problem. They…