tl;dr
git checkoutis the swiss army of git commands. If you prefer a semantically more meaningful command for restoring tasks, usegit restoreinstead.With this command you can ...
- ... do unstaging -
git restore --staged- ... discard staged changes -
git restore --staged --worktree- ... discard unstaged changes -
git restore- ... restore deleted files -
git restore- ... restore historic versions -
git restore --source- ... recreate merge conflicts -
git restore --merge- ... specifiy...
You have uncommited changes (you can always check by using git status), which you want to discard.
Now there are several options to discard these depending on your exact situation.
The headlines will differentiate the cases whether the files are staged or unstaged.
tl;dr
In RubyMine you can use find and replace with capture groups
(.*?)and backreferences$1(if you have several groups:$[Capture-Group ID]).
Named captures(?<text>.*)are also supported.
If you want to replace double quotes with single quotes, replacing every " with a ' is prone to errors. Regular expressions can help you out here.
.* icon next to the "find" field).To allow HTTP 304 responses, Rails offers the fresh_when 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 expens...
When you build a JSON API you need to come up with a style to represent attributes, pagination, errors or including associated objects. Instead of reinventing the wheel, you may reuse successful API designs.
JSON:API specifies common features found in most JSON APIs, like pagination, ordering and nested resources. The spec looks very similar to how one would build an API with Rails and uses similar patterns. Even if you don't plan on supporting the whole spec, it can still make sense to know how th...
When working with feature branches, stale branches pile up over time. It's best to remove them right after merge, locally and on the remote, but it is a little tedious: you need to remember it, and perform the few steps manually each time.
Enter Git hooks. The folks at Liquid Light have built a little post-merge hook that will delete a feature branch on confirmation....
Recently we detected a memory leak in one of our applications. Hunting it down, we found that the memory leak was located in Rails' #prepend_view_path. It occurs when the instance method prepend_view_path is called in each request, which is a common thing in a multi-tenant application.
On top of leaking memory, it also causes a performance hit, since templates rendered using the prepended view path will not be cached and compiled anew on each request.
This is not a new memory leak. It was [first reported in in 2014](https://github.com/...
It might sometimes be useful to check whether your Rails application accesses the file system unnecessarily, for example if your file system access is slow because it goes over the network.
The culprit might be a library like carrierwave that checks file existence or modification times, whereas your application could determine all this from your database.
One option it to use strace for this, which logs all system calls performed by a process.
To do this, start your rails server using something like
DISA...
The gemspec for gems allows to add metadata to your gem, some of which have a special meaning and are helpful for users.
You can provide links to your Github bugtracker or changelog file that are then used on the rubygems page of your gem (in the sidebar, e.g. see gem page of consul).
Here are some keys that should be filled:
Gem::Specification.new do |s|
s.name = 'my-gem'
s.homepage = 'https://github.com/makandra/my-gem'
s.metadata = {
'source_code_uri' => s.homepage,
'bug_tracker...
This card explains how to generate an entity relationship diagram for your Rails application.
We also show how to limit your ERD to a subset of models, e.g. models inside a namespace.
Sometimes we write plain SQL queries in migrations so we don't have to mock ActiveRecord classes. These two migrations do the same:
class Migration1 < ActiveRecord::Migration[5.2]
class User < ActiveRecord::Base; end
def up
add_column :users, :trashed, :boolean
User.update_all(trashed: false)
end
end
class Migration2 < ActiveRecord::Migration[5.2]
def up
add_column :users, :trashed, :boolean
update("UPDATE users SET trashed = #{quoted_false}")
end
end
The plain SQL migration is less code, but h...
You want to deploy new features but the latest commits are not ready for production? Then use git merge master~n to skip the n-last commits.
Tip
A big advantage of merging vs. cherry-picking is that cherry-picking will create copies of all picked commits. When you eventually do merge the branch after cherry-picking, you will have duplicate commit messages in your history.
It's time for a production deployment!
git log --pretty=format:"%h - %s" --reverse origin/production..origin/master
0e6ab39f - Feature A
6396...
Sometimes you need to access a dev server running on localhost from another machine that is not part of the same network. Maybe you want to use your phone to test a web page, but are only in a guest WiFi. In the past, we often used some port forwarding or other techniques to expose the service to the internet.
Enter ngrok, a command line tool that gives you an on-the-fly internet...
Since Rails 6.1, if we use where.not with multiple attributes, it applies logical NAND (NOT(A) OR NOT(B)) instead of NOR (NOT(A) AND NOT(B)). If you do not take care, this change will increase the matched set.
"Don't send newsletters neither to admins nor to trashed users!" becomes "Don't send newsletters to trashed admins".
User.where.not(role: 'admin', trashed: true)
# Before Rails 6.1, with NOR
=> "SELECT "users".* FROM "users" WHERE "users"."role" != 'admin' AND "users"."trashed" != TRUE"
# Equivale...
You can use RSpec::Matchers.define_negated_matcher to define a negated version of an existing matcher.
This is particularly useful in composed matcher expressions or to create more expressive and meaningful matchers.
RSpec::Matchers.define_negated_matcher :not_change, :change
describe 'A negated matcher' do
it 'can be used to chain negated changes' do
expect { subject.maybe_change(object) }
.to not_change(object, :attr_1)
.and not_change(contract, :attr_2)
end
end
RSpec::...
Proxy caching is a good feature to serve your publicly visible application content faster and reduce load on your servers. It is e.g. available in nginx, but also affects proxies delivered by ISPs.
Unfortunately, there is a little problem in Rails < 6.1 when delivering responses for different MIME-types. Say you have an arbitrary route in your Rails application that is able to respond with regular HTML and JSON. By sending the specific MIME type in the Accept header, you tell the application to either return HTML (text/html) or JSON (`t...
From Exploring ES6:
Module imports are hoisted (internally moved to the beginning of the current scope). Therefore, it doesn’t matter where you mention them in a module and the following code works without any problems:
foo(); import { foo } from 'my_module';
When you're not aware of import hoisting you may be surprised that your code runs in a different order than you see in the source file.
The example below is taken from the [...
Jasmine is a great way to unit test your JavaScript components without writing an expensive end-to-end test for every small requirement.
After we integrated Jasmine into a Rails app we often add an E2E test that opens that Jasmine runner and expects all specs to pass. This way we see Jasmine failures in our regular test runs.
In a [feature spec](https://relishapp.com/rspec/rspec-rails/docs/feature-spec...
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 tests. This card focuses on a specific class of feature with heavy side effects, mostly on on the UI. Features like the following can amplify your flakiness issues by unexpectedly changing elements, causing excessive requests or other timing issues:
This RailsCast demonstrated a very convenient method to activate VCR for a spec by simply tagging it with :vcr.
For RSpec3 the code looks almost the same with a few minor changes. If you have the vcr and webmock gems installed, simply include:
# spec/support/vcr.rb
VCR.configure do |c|
c.cassette_library_dir = Rails.root.join("spec", "vcr")
c.hook_into :webmock
end
RSpec.configure do |c|
c.around(:each, :vcr) do |example|
name = example.metadata[:full_descripti...
You want to use <input type="number"> fields in your applications.
However, your desktop users may encounter some weird quirks:
to_i in Ruby) you'll end up with wrong values (like 1 instead o...Event delegation is a pattern where a container element has a single event listener that handles events for all descendants that match a CSS selector.
This pattern was popularized by jQuery that lets you do this:
$('.container').on('click', '.message', function(event) {
console.log("A message element was clicked!")
})
This technique has some advantages:
Sometimes a link or input field has no visible label. E.g. a text field with a magnifying glass icon 🔎 and a "Search" button does not really need a visible label "Query".
For accessibility reasons it is good practice to give such a field an [aria-label] attribute:
<input type="search" aria-label="Search contacts">
This way, when a visually impaired user focuses the field, the screen reader will speak the label text ("Search contacts").
Info
Without an `[aria-...
git --fixup is very handy to amend a change to a previous commit. You can then autosquash your commits with git rebase -i --autosquash and git will do the magic for you and bring them in the right order. However, as git --fixup wants a ref to another commit, it is quite annoying to use since you always have to look up the sha of the commit you want to amend first.
Inspired by the [shortcut to checkout recent branches with fzf](https://makandracards.com/makandra/505126-g...