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Logging Policy

There are different points of view on how logging levels should be used in code. I will share mine.

My assumption is: “There should be no errors in logs when everything is fine.”

How to Start Testing UI Before Backend is Ready

Recently I was asked how to start with testing UI before backend is completed. It depends on the product a lot. But when we’re talking about web, it is often not clear how the final solution should look like and behave. If so, it is not reasonable to spend much time writing UI tests using tools like Selenium before the first prototype is ready. It is not reasonable to write a presentation layer and, in some cases, a business logic on server side before it is clear what kind of data is required for UI. To deal with it I suggest starting with UI mockups and use fake data to start prototyping. It is very easy if you’re writing single page application (SPA): just put some JSON files as static resources and read this files in applications. For more complex cases like handling POST requests you may use simple mock server like gulp-connect. This is required for development so your UI developers don’t even need any server running. Once you’re a bit confident how your UI will look like and behave, it comes the time to cover it with some tests. When using Selenium you will normally ends up with developing some DSL framework for your tests which will include some custom assertions and methods to execute common tasks like user login and filing some forms. Now you should prepare more test data and put it in the same JSON files. Most likely, you will need fake server like gulp-connect in this stage. Use PageObjects to abstract your tests from minor (or even major) future changes in the UI.

Selenium Tests with Maven and Selenide

Selenide is nice wrapper around selenium web driver allowing to simplify writting UI tests with Selenium.

Some of the cook features are:

  1. jquery-like selector syntax, e.g. $("div.myclass").is(Condition.visible)
  2. Automatic screenshots on assertion failure
  3. Easy starting Selenium WebDriver
  4. And others

So, let’s write some tests on selenide and make it run from maven in a normal browser or in headless mode.

Implementing Automatic Reconnection for Netty Client

One of the first requirement of Netty ISO8588 client connector was the support for automatic reconnect.

One of the first receipts I came across was Thomas Termin’s one. He suggests adding a ChannelHandler which will schedule the calling of client’s connect() method once a Channel becomes inactive. Plus adding ChannelFutureListener which will re-create a bootstrap and re-connect if initial connection was failed.

Although this is a working solution, I had a feeling that something is not optimal. Namely, the new Bootstrap is being created on every connection attempt.

So, I created a FutureListener which should be registered once a Channel is closed.