by Paweł Chudzik

Collection like objects in python


Collections are an important part of every programming language. In python, there is a couple of built-in collections like list, set, dictionary but I’m not going to dig into them now. In this post, I’ll explore what it takes to implement collection like objects on your own using collections protocol.

15 Apr 2020

Object oriented programming in Python


Working with python is fun (as with any language you get hooked up on). You can write simple scripts with it, or complex programs and utilities. The most surprising thing for people coming from the java world might be that in this "scripting" language everything is an object. In this post, I’ll explore basic protocols available for user-defined objects.

25 Mar 2020

Testing randomness


While deep diving into the code I very often see people struggle when testing random changing/things. There is a really simple solution for this and in this blog post, I’m going to show you "one simple trick" that will fix this problem.

20 Mar 2018

Events in spring v2


Last time I wrote about events in a spring based application I’ve introduced some basics on how events can be dispatched using spring infrastructure. In this post, I’m going to dig deeper into an order of handlers, exceptions and asynchronous events handlers.

29 Sep 2017

Inheritance gone wrong


We all know how inheritance works and implemented some kind of class hierarchy at least few times during our career. Some of us know already that inheritance is not the silver bullet. Some of us know that inheritance must not be overused and considered with caution. Now I’m going to show you how choosing the quick win might cost you some unexpected troubles in the future.

15 Aug 2017

Events in spring


With spring 4.2 (released more than one year ago) serious improvements regarding embedded events were made. You probably already know it, but I’ve never had a chance to properly investigate it. Lately, when digging into code base of the system I’m currently working on I got an opportunity to see it in action and after quick glimpse, I decided to investigate it a bit further.

1 Aug 2017

Immutability in angular


Some time ago I’ve been struggling with mapping hierarchical data structure in angular. Labels hierarchy was complex (like 4 levels deep with multiple parents, multiple children, basically graph like structure with some logic behind it). In the end it was/is still working but that’s the best I can say about it.

11 Jul 2017

Optimistic locking pitfalls


Optimistic locking is concurrency control method that allows to execute multiple transactions simultaneously as long as they don’t interfere which each other. That’s definition from wikipedia. You probably already know that Hibernate supports optimistic locking and all you have to do in order to implement optimistic locking in you app is to add @Version on number or timestamp field and you are good to go. Right?

27 Apr 2017

Page object pattern for javascript components testing


Page object pattern is common practice when writing automated tests using selenium. It allows to gather all possible operations on the page in one place and hide page implementation details from test case. Page object pattern can be used in the same way for angular directives, react and [put framework name here] components.

23 Feb 2017