Dealing with Solr's "404 Not Found" response
When your Solr seems to be started properly (a process is running with the correct data directory) but never responds properly and replies (via the API or web interface) with...
404 "Not Found"
... check if Solr's log directory is actually writable for the user running it.
Related cards:
Fixing flaky E2E tests
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 ...
Async control flow in JavaScript: Promises, Microtasks, async/await
Slides for Henning's talk on Sep 21st 2017.
Understanding sync vs. async control flow
Talking to synchronous (or "blocking") API
print('script start')
html = get('/foo')
print(html)
print('s...
Using feature flags to stabilize flaky E2E tests
A flaky test is a test that is often green, but sometimes red. It may only fail on some PCs, or only when the entire test suite is run.
There are many causes for flaky...
JavaScript without jQuery (presentation from 2019-01-21)
Summary
- We want to move away from jQuery in future projects
- Motivations are performance, bundle size and general trends for the web platform.
- The native DOM API is much nicer than it used to be, and we can polyfill the missing pieces
- Un...
Lightning Talk: Coverage based Test Case Prioritization in Ruby on Rails
For my computer science bachelor's thesis I programmed and evaluated a CLI Test Case Prioritization (TCP) tool for makandra. It has been written as a Ruby Gem and was tested and evaluated against one Ruby on Rails project....
How to: Upgrade CarrierWave to 3.x
While upgrading CarrierWave from version 0.11.x to 3.x, we encountered some very nasty fails. Below are the basic changes you need to perform and some behavior you may eventually run into when upgrading your application. This aims to save you some...
Video transcoding: Web and native playback overview (April 2020)
Intro
Embedding videos on a website is very easy, add a <video> tag to your source code and it just works. Most of the time.
The thing is: Both the **operating system and Browser of your client must support the container ...
SAML Single Logout (SLO)
There are two ways a logout in SAML can happen: Service Provider (SP) initiated and Identity Provider (IDP) initiated logout. I'll explain how to implement both flows with devise_saml_authenticatable.
Note
SAML also supports a `S...
How to make changes to a Ruby gem (as a Rails developer)
At makandra, we've built a few gems over the years. Some of these are quite popular: spreewald (> 1M downloads), active_type (> 1M downloads), and geordi (> 200k downloads)
Developing a Ruby gem is different from developing Rails applications, w...
The Ruby Object Model
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...