...value and produce a lost update. The Postgres-native fix is to compute the increment server-side inside an atomic INSERT...
...ON CONFLICT DO UPDATE statement and gate it by...
...billing_period_id: current_billing_period.id ) end end Why a unique index The unique index is a storage-level constraint: Postgres rejects duplicate keys at insert time, before commit. Two consequences:
When your public-facing application has a longer downtime for server maintenance or long migrations, it's nice to setup a maintenance page to inform your users. When delivering the...
...maintenance page, be very careful to send the correct HTTP status code. Sending the wrong status code might get you kicked out of Google, or undo years of SEO work...
...old to match the format created by pg_dump. The version of the PostgreSQL server doesn't matter here. For example, the official Ubuntu 20.04 sources include only PostgreSQL...
...amd64] after deb so that it reads deb [arch=amd64] https://... or deb [arch=amd64 signed-by=.... Workaround Step 2: Connect with host option The latest PostgresQL client will only...
...If you want the actions element to float on the left, you'd just say this in your CSS: #actions { float: left; } Unfortunately, any content of the content's text...
If you don't want that but actually wish for longer text to stay on the same vertical boundaries, use overflow: hidden on the element whose content you don...
When you load a with a nonce, that script can await import() additional sources from any hostname. The nonce is propagated automatically for the one purpose of importing more scripts. This is not related to strict-dynamic, which propagates nonces for any propose not limited to imports (e.g. inserting elements). Example We have a restrictive CSP that only allows nonces: Content-Security-Policy: default-src 'none'; script-src 'nonce-secret123' Our HTML loads script.js using that nonce: Our script.js imports other.js without a nonce: let other = await import('other.js') console.log("Look, script.js has imported %o", other) The import succeeds without a nonce, due to implicit nonce propagation. Why this is useful In modern build pipelines, code splitting (chunking) is implemented using dynamic imports. Nonce propagation allows us to use automatic chunking with restrictive, nonce-based CSPs without using strict-dynamic. E.g. esbuild automatically groups dynamically imported modules into chunks, and writes that chunk to disk. The compiled build has an await import('assets/chunk-NAXSMFJV.js'). There's no way to inject a nonce into that import(), but implicit nonce propagation still allows the request. Should I worry about this? It would require some truly strange code for user input to make it into an import() argument. I wouldn't lose sleep over this. Is this a browser bug? It is by design. Here are some sources: HTML Spec Section 8 (Web Application APIs) (search for "descendant script fetch options") Chromium test ensuring none propagation Firefox bug implementing nonce propagation CSP issue: Someone concerned about propagation being a vulnerability CSP issue: Proposal for import-src that went nowhere Are other CSP sources also propagated? No, only nonces. In particular host-based CSPs do not propagate trust. For example, you only allow scripts from our own host (no nonces): Content-Security-Policy: default-src 'none'; script-src 'self' Our HTML loads script.js from our own host: Our script.js imports other.js from a different host: let other = await import('https://other-host.com/other.js') This fails with a CSP violation: Executing inline script violates the following Content Security Policy directive 'script-src 'self''
options.add_option(:web_socket_url, true) options.add_option(:page_load_strategy, 'none') # required for selenium-webdriver 4.27+ end Capybara::Selenium::Driver.new(app, browser: :chrome, options: options) In combination with...
...stay open until handled. Note Setting the unhandled prompt to a hash is supported since selenium-webdriver 4.36 Note that you also need to set the :page_load_strategy to...
...any of the gems that GEM depends on. For the example above you would say: bundle update cucumber-rails --conservative If Bundler cannot update due to transitive dependencies, check if...
...for old versions of bundler The options below might be relevant if you're stuck with Bundler < 1.14: Option 1 This will work if all dependencies for the update are...
To work with other type of nodes (like text, comment or CDATA sections) you need to: Retrieve child nodes contents() (which behaves like children() except that it returns...
...element and returns an array of all child nodes that are text nodes: function selectTextNodes($container) { return $container.contents().filter(function() { return this.nodeType === 3; }); } Also check out this list of existing...
Ubuntu 18.04 uses systemd to manage services. There are basically two commands for listing all services and manipulating the state of a certain service: service and systemctl: service manages System...
...which system V init scripts are available and running / not running, you can use service --status-all: >service --status-all [ + ] acpid [ - ] alsa-utils [ - ] anacron [ + ] apache-htcacheclean [ - ] apache2 [ + ] apparmor [ + ] apport
If you migrate a Rails application from Sprockets to Webpack(er), you can either transpile your CoffeeScript files to JavaScript or integrate a CoffeeScript compiler to your new process. This...
...to the global namespace, define them on window directly: -class @User +class window.User Replace Sprocket's require statement with Webpacker's import statement to load dependencies. -#= require ./person +import './person...
...Optionen können optional enthalten sein? Für was dient der User-Agent Header? Was tut der Set-Cookie Header? Was sind Cookies? Was hat es mit HTTP keepalive auf sich?
...Beyond with Socket.io WebSockets Explained Cross-Origin Resource Sharing (CORS) Content Security Policy (CSP) HTTP Strict-Transport-Security (HSTS) HTTP authentication Nginx Nginx Admin Guide Nginx docs -> Es ist empfehlenswert...
By activating strict_loading you force developers to address n+1 queries by preloading all associations used in the index view. Using an association that is not preloaded will raise...
...an ActiveRecord::StrictLoadingViolationError. I think it's a good default to activate strict_loading in your controllers' #index actions. This way, when a change introduces an n+1 query, your...
When using tmux, selecting and copying multiple lines of text can be a hassle, especially when using splits (highlighting lines will cross pane borders, copying contents from the other pane...
...too) and when the user wishes to copy (thus, select) lines that have already scrolled out of the viewport in the current pane. One idea would be to enable mouse...
RubyMine has a collaboration feature called "Code With Me". Using it, you can invite someone into your local editor to work together. This is nicer to the eyes and much...
...more powerful than sharing code through some video chat. How to Getting started is really simple: Click the "add person" icon in the top-right editor corner (or hit Ctrl...
To apply transparency to an element, you can use opacity in CSS. However, sometimes you don't want to make the entire element transparent, only a color.
...modern CSS, you can simply generate non-opaque versions of a color without any preprocessor like Sass. This card describes how to do that. Note that we're not talking...
Option 0: Download from the official page (preferred) Open https://googlechromelabs.github.io/chrome-for-testing/ In Section "Stable" > chromedriver / linux64 > Download ZIP from URL Take the chromedriver binary from the ZIP file and...
...your path like this: echo "export PATH=$PATH:$HOME/bin" >> $HOME/.bash_profile Option 2: Use apt source Warning Wo no longer recommend this option. After a chrome update, the chromedriver package sometimes...
...create a Gemfile for installing all required gems. Gemfile # Gemfile gem 'docker-api' gem 'serverspec' Then we install them bundle install Preparation Create the directory where the Tests are going...
...to live. Add the folder to .dockerignore since we wo not want the test to be included within our final container image. mkdir spec echo spec >> .dockerignore spec/spec_helper.rb
Understand how nested attributes appear in the params. See how the Rails form helpers encode the names of nested inputs. Understand how the record and all of its nested...
...attributes are saved in a transaction. That means the entire structure is saved or not. Resources Rails Guide: Nested forms Nested Forms in Rails Popular mistakes when using nested forms...
...on a Rails record is converted to UTC using to_s(:db) to be stored, and converted back into the correct time zone when the record is loaded from the...
...This is now UTC Problem That will blow up in your face when you send times to attributes that expect dates, just because those times will also be converted using...
...will tell you if there are any and you should not commit when you see them. So go ahead and switch your editor/IDE to automatically remove them for you.
Note that except for RubyMine, the following changes will remove trailing white-space on all lines, not only those that you changed. While this should not be a...
Simplecov is a code coverage tool. This helps you to find out which parts of your application are not tested. Integrating this in a rails project with rspec, cucumber and...
Add it to your Gemfile and bundle group :test do gem 'simplecov', require: false end Add a .simplecov file in your project root: SimpleCov.start 'rails' do
# features/support/database_cleaner.rb DatabaseCleaner.clean_with(:deletion) # clean once, now DatabaseCleaner.strategy = :transaction Cucumber::Rails::Database.javascript_strategy = :deletion Cucumber & Rails 2 The latest available cucumber-rails for Rails 2 automatically uses database...
...off. To have database_cleaner work correctly: Add the attached database_cleaner.rb to features/support/ Make sure features/support/env.rb contains the following lines in this order: # features/support/env.rb require 'features/support/database_cleaner' require 'cucumber/rails/active_record' require 'cucumber/rails/world...
If your app does not need to support IE11, you can use most ES6 features without a build step. Just deliver your plain JavaScript without transpilation through Babel or TypeScript...
...and modern browsers will run them natively. Features supported by all modern browsers include: fat arrow functions (() => { expr }) let / const class async / await Promises Generators Symbols Rest arguments (...args)
...index do |person, index| person.award_trophy(index + 1) end Ruby's map with index Similarly, you may need an index when using other methods, like map, flat_map, detect (when...
...you need the index for detection), or similar. Here is an example for map: people.map.with_index do |person, index| person.at_rank(index + 1)