Terser is a really good minifier ("compressor") for JavaScript code. I'm often surprised by the thoughtfulness of its compressed output. Let's take this function: function fn() {
...this to the following code: console.log(a||b?"foo":c()) Note how: The if statement has been replaced by a tertiary expression. This is often less readable, but it doesn...
...Plotting graphs in Ruby with Gruff, which comes handy for many uses cases, you sometimes might need configuration for more advanced plots, e.g. for academic concerns. Then using Gnuplot, the...
...first academic open source plotting software, might be a good option. There are several wrappers for Ruby available and I mainly looked at one of the two most frequently used...
...command-line tool for REPL (Read Eval Print Loop). Type gem help info to see a list of available switches. Note that the Ruby API offers a bit more insight...
...Gem Ruby API (at runtime) First, get the Gem::Specification of the gem you are looking for. That object holds all the information from the gem's gemspec file, and...
If you want to find the commits that touched a specific text in a file, use git log -S 'text in the code' -- path/to/file If you use tig you may...
...run a similar command to get a navigatable list of affected files: tig -S'text in the code' Example Here is an example, where the move of the convert_number...
PostgreSQL can cosplay as a full-text search engine. It doesn't have the features or fidelity of ElasticSearch or Algolia, but it's good enough if you just need...
...to search and rank large volumes of text. This card will teach you how to index, search and rank your Rails models in a PostgreSQL full-text index. We will...
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...
...on logout and devise does not do that we get a Unsafe redirect to "https://some-idp.example.com/realms/dev/protocol/saml?SAMLRequest=fZJBb9QwEIX%2FSm45zcZx4j...", pass allow_other_host: true to redirect anyway. upon trying to logout.
...an extra rendering step just for your JavaScript. An example would be: function logBoxHeight() { box.classList.add('super-big'); console.log(box.offsetHeight); // Forces the browser to re-render *now* } Verdict: Make sure you...
...always first read, then write style-relevant values. How to debug: Chrome shows warning icons in the event list in the Timeline for scripts that cause layout trashing. Performance issue...
Applications often show or hide elements based on viewport dimensions, or may have components that behave differently (like mobile vs desktop navigation menus). Since you want your integration tests to...
...behave consistently, you want to set a specific size for your tests' browser windows. Using WebDriver options / Chrome device metrics For Google Chrome, the preferred way is setting "device metrics...
...method for controllers. The most common way is to pass an ActiveRecord instance or scope, and fresh_when will set fitting E-Tag and Last-Modified headers for you. For...
...scopes, an extra query is sent to the database. fresh_when @users If you do not want that magic to happen, e.g. because your scope is expensive to resolve, you...
...is a gem for working with daytimes. That's a tuple of (hour, minute second) without a day, month or year. Another additional gem? Thus SQL has a time datatype...
...for storing time of day in the format hh:mm:ss, neither Ruby nor Rails themselves offer an elegant way to deal with day times. Time and DateTime both handle...
...notice that the records you create are not deleted and will bleed into your specs the next time you run them. You probably have DatabaseCleaner configured to take care of...
...not bloating your test database with old records: RSpec.configure do |config| config.before(:suite) do DatabaseCleaner.clean_with(:deletion) end config.before(:each) do DatabaseCleaner.strategy = :transaction end config.before(:each, transaction: false) do DatabaseCleaner.strategy...
...been released just a few days ago, allowing us to use Webpack 4. I successfully upgraded an existing real-world Webpack 3 application. Below are notes on everything that I...
Note that we prefer not using the Rails asset pipeline at all and serving all assets through Webpack for the sake of consistency. Preparations Remove version locks in Gemfile...
...for file uploads. CarrierWave has an integrated processing mechanism for different file versions with support for ImageMagick through CarrierWave::MiniMagick (which requires the mini_magick gem). In case your processing...
...runs into an error, CarrierWave will just swallow it and rethrow an error with a very generic message like Processing failed. Maybe it is not an image? which does not...
The shell variable PS1 holds your bash prompt. You might want to change it to serve your needs best. Here is how to: General non-printing escape sequences in your...
=> ✔ mycomputer ~/projects/platforms master > _ # Arne's epic timestamped prompt with return status indicator and status-colored (green if fresh, or red if unstaged, or yellow if staged) git branch:
This note is a reminder that there is something called AppArmor that could cause weird errors ("File not found", "Can't open file or directory", ...) after configuration changes, e.g. when...
...in licensing, we cannot provide Elasticsearch versions >= 8.0. Version 7.17.x will reach EOL status with the release of Elasticsearch version 9. We have decided to use OpenSearch as a...
...replacement, since it is a fork of Elasticsearch version 7.10.2, still running under the previous licensing model and wire-compatible. A more detailed reasoning can be found on their website...
...with two matchers that test for equality. The first is toBe: expect(first).toBe(second) toBe passes when first === second. Unfortunately this is useless for non-primitive values because JavaScript...
...is a horrible language. However, Jasmine comes with another matcher toEqual: expect(first).toEqual(second) This matcher behaves as a human would expect for types like the following: Arrays
...to be done separatly for each node version on your system, though. Install yarn 1 system-wide via apt The yarn package depends on the nodejs debian package, but with...
curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | gpg --dearmor | sudo tee /etc/apt/keyrings/yarn.gpg >/dev/null echo "deb [signed-by=/etc/apt/keyrings/yarn.gpg] https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list sudo apt-get update...
...status code 400) |_http-title: 400 The plain HTTP request was sent to HTTPS port | ssl-cert: Subject: commonName=www.makandracards.com/countryName=DE | Not valid before: 2015-10-14T12...
...Not valid after: 2016-10-14T12:42:03+00:00 |_ssl-date: 2016-08-05T11:33:52+00:00; +9d23h48m18s from local time. | tls-nextprotoneg: | h2
...Mocking the time zone You can't really change the local time zone of the Selenium-controlled browser. What you can do is change the time zone of the process...
...setting this from an individual test, since you don't know whether or not the Selenium-controlled browser has already launched. Note that we have only tested this with a...
I recently noticed a new kind of flaky tests on the slow free tier GitHub Action runners: Integration tests were running on smaller screen sizes than specified in the device...
...metrics. The root cause was the use of Selenium's page.driver.resize_window_to methods, which by design does not block until the resizing process has settled: We discussed this issue...
Debouncing a method call delays its execution until after a specified time has passed. If it's called again before that time has passed, its execution is delayed again.
...would be run more often than it needs to. One example for that are scroll event handlers in JavaScript: You want to react to a user scrolling, but it's...
Is your application doing something expensive every few seconds? Maybe an animated slider that rotates images? Maybe you are updating data over the network every five minutes?
...this if the your document tab is not even visible to the user. This saves your user's battery and data plan. You can ask document.visibilityState whether this tab is...
Rails wraps your parameters into an interface called StrongParameters. In most cases, your form submits your data in a nested structure which goes hand in hand with the strong parameters...
...However, there are cases where this does not fit your use case, or has side effects. If you do it differently, be extra careful not to introduce security issues.