In Ruby (almost) everything is an Object. While this enables a lot of powerful features, this concept might be confusing for developers who have been programming in more static languages, such as Java or C#. This card should help understanding t...

Speaker today is Henning Koch, Head of Development at makandra.

This talk will be in German with English slides.

Introduction

As web developers we work with JavaScript every day, even when our backend code uses anothe...

Cucumber up to version 2 had a neat feature called Step Argument Transforms which was dropped in favor of Cucumber 3 [ParameterTypes](https://cucumber.io/blog/upgrading-to-cucum...

An end-to-end test (E2E test) is a script that remote-controls a web browser with tools like Selenium WebDriver. This card shows basic techniques for fixing a flaky E2E test suite that sometimes passes and sometimes fails.

Although many examples ...

Several Rails migration methods accept index: true as an option to create an index. In some cases (like #add_column), this option is silently discarded. Know what you are doing, or use #add_index instead.

Example

Consider the following ...

Introduction

Most of the time it is a tedious task to apply a code style guide to an existing code base as there are likely to be a lot of conflicts. At makandra we are using [makandra-rubocop](https://makandracards.com/makandra/62188-makandr...

When you write your next CarrierWave uploader, consider processing your images with libvips instead of ImageMagick.

Reasons for libvips

There are several **upsi...

Not all email clients support external images in all situations, e.g. an image within a link. In some cases, a viable workaround is to turn your images into inline attachments.

Note

Rails provides a simple mechanism to achieve this:

• [h...

In Ruby 1.9, instance_eval calls the block the with receiver as the first argument:

• In Ruby 1.8, receiver.instance_eval(&block) calls block.call()
• In Ruby 1.9, receiver.instance_eval(&block) calls block.call(receiver)

This will blo...