In CI test runs I noticed that string sorting order changed after switching from a debian-based PostgreSQL docker image to one that is based on Alpine Linux.
...sorting: bar Bar foo Foo Alpine image sorting: Bar Foo bar foo Explanation Alpine Linux is a very slim linux distribution that results in small docker image sizes (roughly 100MB...
...MySQL and you know the "error" is okay (e.g. you've executed the same statement at the same time on 2 masters which sync each other), you can skip this...
...error and continue with the replication without having to set up the slave from the ground up. stop slave; set global sql_slave_skip_counter = 1; start slave;
In Rubocop you might notice the cop Style/CaseEquality for e.g. this example: def foo(expected, actual) expected === actual end In case expected is a Regex, it suggests to change it...
...foo(expected, actual) expected.match?(actual) end In case expected is a Regex or a String, you need to keep ===. Otherwise the actual expression is always converted to a regular expression...
...what git checkout and git reset do. Git basics A commit holds a certain state of...
...a directory and a pointer to its antecedent commit. A commit is identified by a so-called ref looking something like 7153617ff70e716e229a823cdd205ebb13fa314d. HEAD is a pointer that is always pointing...
You can scale background images in CSS to the container size using background-size (Demo). Commonly, we use contain or cover because we want to preserve the image's aspect...
If you do not want to do that, simply provide scaling values for X and Y: background-size: 100% 100% (a simple 100% would mean 100% auto and respect...
...written in pure Ruby and integrates with Rails applications. It provides features as automatic sizing of dots and lines (the more values, the thinner the graph's elements), custom or...
...predefined themes, different styles (bar, line, dot and many more) and multiple graphs in one chart. Installation In your Gemfile: gem 'rmagick', :require => false gem 'gruff' Then run bundle install...
gem install foobar --version="=2.3.0.alpha2" Also bundle update will never update a stable version to a pre-release version unless the user explicitly requests it in the Gemfile...
...gem 'foobar', '=2.3.0.alpha2' A note on Semantic Versioning Semantic Versioning has a naming convention for pre-releases that is incompatible with that from RubyGems. In Semantic Versioning, the version...
...entering only http://example.com/). If you want to make a request to that site's web server without actually talking to www.example.com (e.g. because this is a load balancer...
...s address but you want to access one specific machine), you cannot just request machine1.example.com or localhost as the above vhost will redirect your request. When talking HTTP 1.1, your...
How to ignore new files Globally Add the path(s) to your file(s) which you would like to ignore...
can’t find executable rails for rails-3.2.3 (Gem::Exception) ... one of several...
...things might be wrong. You're using RVM It's possible that you have a system-wide gem executable (like rails) that requires a gem that is not available in...
...you want to clean up this code with the modularity gem, you might try something like this: class Foo does 'bar' end module BarTrait as_trait do class Bar
...you would have to change all references accordingly, which is quite unpleasant. You can solve it like that: module BarTrait as_trait do class self::Bar end end end
Web forms can be made much more usable with a few HTML attributes. Short summary: type: Tells browsers about the input data type. Mobile browsers will select a virtual keyboard...
...based on this value. Some browsers will add simple validation, e.g. for type email. inputmode: Direct hint about the virtual keyboard to use. Inferred from type, but can be very...
Sometimes I ran across a GitHub merge request of a gem where it was not completely obvious in which version the change was released. This might be the case for...
Git can help you to find the next git tag that was set in the branch. This usually has the name of the version in it (as the...
On your local system that only hosts non-critical development data and only you have access to, you can store MySQL's root password in your home directory so you...
...out of the question if there's any confidential data in your databases. Assuming diligent screen-locking, an encrypted hard disk and correct permissions set on your credential file, it...
It is possible to manipulate the forwarded ports of an established interactive SSH session. This is done by opening the command line with the escape character ~C. This will open...
...a ssh> prompt. If it doesn't, make sure it's the first character in a line, i.e. press enter first. You have following commands at your disposal
...flaky tests. You should always try to fix those instead of rerunning them regularly. Setup Configure RSpec to persist the result of your test runs to a file. This is...
...necessary to be able to rerun examples. Add this to your spec/spec_helper.rb : config.example_status_persistence_file_path = 'spec/examples.txt' Rerun all failed examples using --only-failures bundle exec rspec --only-failures...
...lot less than you think. "private" does not apply to class methods defined on self This does not make anything private: class Foo private def self.foo 'foo' end end
...need to use private_class_method instead: class Foo def self.foo 'foo' end private_class_method :foo end "private" does not apply to define_method This does not make anything...
A comprehensive introduction to sending HTML emails. Intro: HTML email: Two words that, when combined, brings tears to a developer’s eyes. If you’re a web developer, it’s...
...in your career, whether you like it or not. Coding HTML email is old school. Think back to 1999, when we called ourselves “webmasters” and used Frontpage, WYSIWYG editors and...
Spreewald's patiently repeats the given block again and again until it either passes or times out. Be careful to give patiently a block that can actually be repeated. E.g...
...the field variable that was defined outside of the block (it's the variable set from the Given block's arguments). Because of this, during the first repetition the value...
...run rake and your code is causing an exception which is not the one shown in your terminal. Rails tries to catch this exception and clean up constants but -- while...
...it's still booting up -- fails on this which causes another exception: rake aborted! cannot remove Object::ClassMethods Running rake with the --trace parameter will give you no love; the...
...file download links in an end-to-end test can be painful, especially with Selenium. The attached download_helpers.rb provides a download_link method for your Capybara tests. It returns a...
details[:disposition] # => 'attachment' or 'inline' details[:filename] # => 'report.txt' details[:text] # => file content as string details[:content_type] # => 'text/plain' Features Compared to other approaches this helper has many useful features...
Capistrano automatically logs each (successful) deployment into a file on your application servers. It is located at the root of your server's project folder, i.e. the parent of releases...
...and current, like so: /var/www/your-project$ ls current log releases repo revisions.log <--- here shared Each line in that file contains the deployed branch, commit, release ID, and username (was read from...
...open a dialog with the route to your dialog's view. tinymce.init({ // ... toolbar: 'myCustomButton', setup: function(editor) { editor.ui.registry.addButton('myCustom Button', { icon: 'document-properties', tooltip: 'Further describe your button here', onAction...
...insertContent', content: linkTag, }); window.parent.postMessage({ mceAction: 'insertContent', content: ' ', }) window.parent.postMessage({ mceAction: 'close' }); }) function buildLinkTag(form) { // do stuff } }) See here for more commands...
Having a unique selector for an element is useful to later select it from JavaScript or to update a fragment with an Unpoly. Haml lets you use square brackets ([]) to...
...with ActiveRecord instances, which have a persisted #id and will hence generate the same selector over multiple renderings of the same view. Example - @users.each do |user| .row[user] = user.name