Tuesday, December 4, 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 submit!");
        return false;
    }
}


Now we have a testable function isFormValid. It’s an example of separating the logic from the UI and the DOM interaction. There is still a DOM element being used but that’s fine as it is easy to create or perhaps mock in writing the test.

Code not worth testing

$(‘.button).click(function() {
  $(‘#my_quote’).css(‘background-color’, ‘red’);
}


This code is still testable despite using some jquery magic. It’s easy to mock out jquery or fake events and DOM enough to test it. Do not test this code. There is no real logic in there and it’s heavily tied to the UI interaction. This may mean a lot of the Javascript you’re writing does not have tests and that’s okay. Interactions like this are still best tested manually and if they fail in a harmful way will be obvious to anyone using the system. Logic errors however can be much harder to spot through manual testing.

Testable closures

function passwordCheckClosure(password) {
  return function(comparePassword) {
    return comparePassword === password;
  }
}


I love closures and closures like this are still really easy to test. Just as I would still expect you to create private methods and properties when doing TDD in C++ or Java. In Javascript I would still expect you to write closures to help build your code into clear abstract interfaces. But as with private methods and constructors you need to avoid hiding everything in closures.

Untestable closures

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

    if (!isFormValid(document.simple_form)) {
        alert("Please fill out all fields before clicking submit!");
        return false;
    }
}


This is just a slight variation on our form valid check above. But now we cannot access isFormValid to test it separate to the validate method as a whole.

 Dependency injection with a closure

// formElenment - jquery reference to the form object
// alertMethod - alert on the browser. something else for console or tests
function attachFormValidator(formElement, alertMethod) {
    function isFormValid() {
        return (formElement.find(‘#name’).val() != "" &&
            formElement.find(‘#email’).val() != "");
    }
    formElement.submit(function(e) {
        if (!isFormValid()) {
          alert("Please fill out all fields before clicking submit!");
          e.preventDefault();
        }
      }
    );
}


This may seem harder to test. We've introduced expections that we’re using jquery and put everything within a function that does not return anything. But it’s actually very testable since we can easily mock out all the objects that we send in and trigger and test those actions through those mocks. Because objects are cheap and easy to construct that means it’s cheap and easy to mock things out.

Next time
Running tests with Jasmine and your web browser

This is part of a series I'm writing for Agile+ on Google+ so you can follow as I post them there

Monday, November 26, 2012

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 expect unit tests in that environment. It may be that your programmers are just copying the latest jquery plugins and performing wonders while writing very little Javascript  If there’s very little Javascript being written then there’s no point trying to automate the testing.

Okay. So do I test in Selenium or Watir?
Wait just a minute now! Those are not unit testing frameworks. They can be great for integration testing to see the behaviour with the DOM and a backend. But TDD requires unit tests that are fast to write and fast to run. I’m going to use Jasmine but there’s lots of other unit test frameworks to pick from and I’ll walk through the ways to run it on a console, through a browser and distributed through many browsers.

Next time
Writing testable javascript and what not to test

This is part of a series I'm writing for Agile+ on Google+ so you can follow as I post them there

Wednesday, September 12, 2012

Place to discuss Agile topics

I haven't been completely idle. Appart from my rambings on twitter and google+ I've also been making regular posts to a new facebook group on Agile Software Development.
I will return to talk about RestScriptFixture, fun with NodeJS and are games (like movies) out of new ideas?

Friday, May 25, 2012

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 RestFixture/lib/*.jar
!path RestFixture/RestFixture.jar

!define expectedReturnHeaders {Content-Length : [\d]+
Content-Type : text/xml }

|!-Table:smartrics.rest.fitnesse.fixture.RestFixture-! | http://localhost:8080|
|GET|/RestFixture?rss|200| ${expectedReturnHeaders} |//title[text()='RestFixture']|
If that runs and passes then congratulations! You've got a working RestFixture install! Step 3: Profit!


Pitfall 1: &
Stuff like /loadpreferences?session=9999&user=admin&module=config would fail and I was scratching my head. Now any good RESTful api designer will tell you that's a stupid url to be using and they'd be write. But it's someone's old mistake and I can either tell them how stupid they are or appreciate the fact it works and move on trying to get everything that's broken working too.
Why did this fail? Well because Fitnesse was turning my & into & and messing up the url with nothing to parse it back. Solution: Surround the url with !- -! to stop Fitnesse doing any parsing on it and it'll work just fine.
Pitfall 2: json + xpath
I was trying to figure out how to handle json that didn't confirm nicely to use xpath commands. Unless your json is wrapped in something like {node: stuff} then the xpath stuff just doesn't work. Something I will try and fix at some point. So i used a lot of the javascript parsing in there to access the jsonbody variable that would work just fine. So I got lots of things like this:
/* javascript */ jsonbody == false;
or this
/* javascript */ 
var match = null;
for (var i=0; i != jsonbody.length && match == null; ++i) {
  var node = jsonbody[i].map;
  if (node.name == 'Bob') {
    match = node;
  }
}
match != null;
or use the let ... js statements like this
response.jsonbody[4].block.name
Pitfall 3: Posting form like data
It's documented in later versions but not in 2.0 beta that you can use set body with url encoded data to behave like posted form data. Very handy. Although I'm still trying to figure out how this can work if combined with a file upload.

Wednesday, May 16, 2012

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:
  1. It is reusable so you can drop it into lots of tests without making new classes all the time
  2. It's a good bridging tool in trying to get developers using fitnesse who are not used to creating an abstraction layer for their tests
  3. It'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 name='Big Joe'|1                       |

!|script|DBQueryFixture|mydatabase                                           |user      |pass         |
|query  |SELECT * FROM users WHERE name='Big Joe'                                                     |
|show   |get row       |0                                                    |and column|name         |
|check  |get row       |0                                                    |and column|city|New York|
So it's pretty straight forward. If you're already familiar with script tables you'll know how you can drop switch between check and show for when you just want to see the result vs when you want to validate it. There are probably lots of statements you'll want to run without looking at the number returned (number of rows modified or -1 if there is an error). My fixuture is hard coded to use a local postgres database (and the postgres jdbc jar is in my lib folder). But it's easy enough to change that for your own version
package com.warmage.util.fixtures;

import java.util.ArrayList;
import java.util.List;
import java.sql.*;

import static util.ListUtility.list;

public class DBQueryFixture {

    // constants
    final private String baseUrl = "jdbc:postgresql://localhost:5432/";

    /**
     * Constructor for script table
     *
     * @param database - Database name
     * @param dbUser   - User to use
     * @param dbPassword - Password to use
     */
    public DBQueryFixture(String database, String dbUser, String dbPassword) {
        try {
            jdbcConnection = DriverManager.getConnection(baseUrl + database, dbUser, dbPassword);
        } catch (SQLException e) {
            System.out.println("Error connecting to the database");
        }
    }

    public int statement(String query) {
            try {
                Statement st = jdbcConnection.createStatement();
                return st.executeUpdate(query);
            }
            catch (SQLException e){
                System.out.println("Error executing statement");
            }
            return -1;
    }

    public void query(String query) {
        try {
            Statement st = jdbcConnection.createStatement(
                  ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
            results = st.executeQuery(query);
        }
        catch (SQLException e){
            System.out.println("Error executing query");
        }
    }

    public String getCell(String column) {
        if (results != null) {
            try {
                return results.getString(column);
            }
            catch (SQLException e){
               System.out.println("Error fetching cell for column " + column);
            }
        }
        return "null";
    }

    public String getRowAndColumn(int row, String column) {
        if (results != null && row >= 0) {
            try {
                // Iterate to the right row
                results.beforeFirst();
                boolean resultsValid = true;
                while(resultsValid && 0 <= row) {
                    resultsValid = results.next();
                    row--;
                }

                if (resultsValid) {
                    return getCell(column);
                } else {
                    System.out.println("Error row count too big");
                }

            }
            catch (SQLException e){
                System.out.println("Error moving through rows");
            }
        }
        return "null";
    }

    private Connection jdbcConnection;
    private ResultSet results = null;
}

Sunday, May 13, 2012

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.

Saturday, May 12, 2012

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 permissions here so may as well make it the owner. This is where FitNesseRoot is going to end up and also where you're going to want any libraries and classes it can include. I found fitnesse isn't very good at using absolute paths when doing includes and also doesn't handle spaces. Something to look out for!

4. Create the folder to store fitnesse logs /var/log/fitnesse
Make sure the fitnesse user can write
5. Create the below file as /etc/init/fitnesse.conf
description "fitnesse: Fitnesse acceptance testing framework"
author "geoff@warmage.com"

start on (local-filesystems and net-device-up IFACE!=lo)
stop on runlevel [!2345]

env USER="fitnesse"
env GROUP="fitnesse"
env FITNESSE_LOG="/var/log/fitnesse"
env FITNESSE_ROOT="/var/lib/fitnesse"
env HTTP_PORT=8081
env JAVA_OPTS=""
env JAVA_HOME="/usr/lib/jvm/default-java"

#limit nofile 8192 8192

pre-start script
    test -f $FITNESSE_ROOT/fitnesse.jar || { stop ; exit 0; }
end script

script
    FITNESSE_ARGS="-p $HTTP_PORT -l $FITNESSE_LOG"
    exec daemon --name=fitnesse --inherit  --chdir=$FITNESSE_ROOT \
        --output=$FITNESSE_LOG/fitnesse-output.log --user=$USER \
        -- $JAVA_HOME/bin/java $JAVA_OPTS -jar fitnesse.jar $FITNESSE_ARGS
end script

6. Link from /etc/init.d/fitnesse to /lib/init/upstart-job
sudo ln -s /lib/init/upstart-job /etc/init.d/fitnesse
Make sure it's executable
sudo chmod +x /etc/init.d/fitnesse
nearly there now

7. Setup run levels for fitnesse to run with
I used sudo sysv-rc-conf -P to see the run levels and turned on 2, 3, 4 & 5. Could probably have dropped 2 but whatever, that's what most use. There seems to be lots of other ways to do this but this is what I did.

That's it! I'm probably forgetting something and I'm sure there's better ways to do some of the steps. There's lots of guides out there if you search 'ubuntu daemon' but knowing the quirks of fitnesse (spaces in folder names? where do you want files?) is still relevant.