Tuesday, January 27, 2015

Book Review: Mockito Essentials

Book Review: Mockito Essentials by Sujoy Acharya

Mockito essentials is a straightforward insight towards writing proper form of unit tests using mockito framework. Targeted at existing developers, this book goes beyond the documented library and explains the method of correctly writing unit tests and its corresponding code.
The book starts by introducing test doubles, or assumptions that we make while writing unit tests which is essentially done through mockito, effectively laying the foundation of the book. Two subsequent chapters are devoted to the innards of the framework - which is very handy if you have mockito's programming reference ready.
However, the main problem of unit test lies in its implementation as real world code is generally not testable and often is unchangeable. Using mockito under BDD tests is also worth mentioning as this concept is not covered elsewhere till now. The book concludes with implementation of mockito based tests over webservices and rich client applications.
Overall, the book not only covers the mockito framework but also covers practical advice regarding testing existing code and making both legacy and new code testable and I'd highly recommend this book if you are looking to write unit tests in java applications.

Disclaimer: I received a copy of this book from packt publication before doing a review.
Access the book here:

Sunday, January 11, 2015

On finding loopholes through visualization

Sometimes, visualization provides you with insight that is not instantly available. for example, I was playing with the open data that Indian Government provides for irrigation methods in different districts of India, and here's the aggregate data:
 The visualization above lists all the power sources used for irrigation across India. In most of the states, this was coming similar to what was expected (such as larger use of solar pumps and windmills in Gujarat and Rajasthan), but there were few anomalies too, like in the display below:
This information is obviously incorrect as someone has erroneously or lazily set all the non manual sources for irrigation to the Other/uncategorized source and thus, this set of data becomes inconsistent with the rest of the data.

Being on the information highway (with Right To Information) is important for India, but still there is still to go before we are able to make this data comprehensive enough for forecasting and predicting useful outcomes.

Wednesday, January 7, 2015

Hack learning android, freelance and other ramblings

In between doing mundane things in life, I've started doing more work to keep myself sharp as my office work has diminished vastly. This year has turned out good for me as I've started freelancing on my own on part-time basis and am currently relearning android application development to take advantages of the newer generation phones and create an app or two. The new android studio merits a mention here - from eclipse, it has now moved to intellij ide and different wizards as well as gradle based build tool is added, which augments development. However, emulating newer mobile devices does not work on my machine as it takes up quite a lot of time to initialize and random crashes also occur, so using a physical devise is the only workable option for now. My approach towards learning has also undergone a change and now I am working in shorter sprints of hack and learn cycles that ease my understanding process.

I get sidetracked by various side projects often and am also preparing for the hybris core and commerce developer certification, which to me seems like a college level exam - you sulk at it till the penultimate day. I do hope that businesses realize the importance of knowledge over a certificate given the presence of questions to be asked in exam over the internet, often called dumps.
Since I am having the luxury of time at my disposal, I am able to plan for my tech startup/business idea that would sustain me in future as well as allow me to be an entrepreneur.

Tuesday, December 30, 2014

Book Review: Learning Python Testing by Daniel Arbuckle

This is a review of Learning Python Testing by Daniel Arbuckle which as its name suggests, delves into testing with python. The testing frameworks covered are already covered in comprehensive python texts but instead of only high level overview, this textbook covers various testing frameworks and approaches in detailed manner.
The first chapter covers various forms of testing - something which could be covered in few subtopics and test driven development could have been discussed in greater detail. It then moves into doctest, which is unique approach in python and was discussed in depth - I've only known it vaguely before and the provided details opened up a sea of possibilities for me. For instance, the AVL tree example provided an excellent demonstration of doctest and is worth quoting. The next chapter provided unit tests with doctest and correctly explained the essence of unit testing. The PID controller example however was confusing and it took me frequently eyeballing the code - the logic used was complicated and consequently the test cases were larger. Next, mock objects were detailed - which are not present in other python texts. unittest.mock library in python3 was explained in depth before covering the details of this module. In the next chapter, the Nose test runner was discussed and its various customizations were also explained.
Test Driven Development was introduced relatively late in the book after all the testing frameworks were covered and covered writing specification and tests before code. For someone new to TDD philosophy, this book offers excellent introduction and covers all its facets and challenging the reader to do more - which I found as a pleasant surprise. This was followed by integration and system testing doctrine. The final chapter covering importance of testing in code coverage, version control and continuous integration wrapped up this handy textbook sufficiently.

Apart from some places where I found the text opinionated with the example taken, I enjoyed the rest of the book and specially places where the reader is asked to get off reading and try things to test his/her knowledge of the topic.

Disclaimer: I received a copy of this book[http://bit.ly/1HKQaIj] for doing its review.

Thursday, December 25, 2014

Book Review: Think Stats

Think Stats by Allen B. Downey

Think Stats presents statistical analysis techniques with a twist - by showing how to code the solution in python rather than applying mathematically. There may be other books on data analysis using various techniques and python libraries, but this book is unique in the sense that it teaches the reader to apply statistics over real world data and answer common questions pertaining to it and one can even feel the author guiding through various exercises. Another takeaway from the book is that it also shows real world applicability- for instance, having empathy and gratitude for people providing personal information used in the creation of the dataset as well as understanding the context of data before applying any algorithm.
Like reviewing other books, I assumed that the potential reader would be new towards statistics and computing statistical methods in general and this book justifies itself by encouraging the reader identify problems and apply relevant algorithms for the same. While I was able to follow the chapters given in the book, the sole use of python was a bit of a concern - if you are comfortable in python, you will feel right at home otherwise the use of specific technology might cause slight disruptions. I prefer javascript based examples over NumPy and SciPy these days, but as these libraries are more mature, It serves as an excellent choice.

Aiming to replace your regular statistical class, all the key topics are presented in a refreshing manner. After discussing data analysis exploration, representation of data is demonstrated using basic methods before proceeding towards more complex ones. Advanced topics like regression and analytic functions are introduced towards the end. Here's the list of chapters in detail.
One issue that I faced was the fact the book went into theory and actual code analysis was missing at places. For instance, I was unfamiliar with pandas DataFrame and it required me to have a look into the code during the course of the book. This book would definitely in my references list for times to come.

Disclaimer: I have been provided a free copy of this book by OReilly under their Blogger review program.