Git: Improve your commits by reviewing changes one-by-one
Git commits should be very deliberate, and only contain changes that you really want to be in there. In order to reduce the chance to accidentally commit something you didn't intend, review your changes before committing.
My preferred way of doing this is (only using git)
git add -N . # Add all paths, but not their contents
git add -p
Git will now show you all your changes in small chunks and ask you in an interactive mode whether you really want to add them.
The most helpful commands are
- y: yes (add the change)
- ...
How to make your application assets cachable in Rails
Note: Modern Rails has two build pipelines, the asset pipeline (or "Sprockets") and Webpacker. The principles below apply for both, but the examples shown are for Sprockets.
Every page in your application uses many assets, such as images, javascripts and stylesheets. Without your intervention, the browser will request these assets again and again on every request. There is no magic in Rails that gives you automatic caching for assets. In fact, if you haven't been paying attention to this, your application is probabl...
Nested ActiveRecord transaction pitfalls
When working with custom transactions and use ActiveRecord::Rollback you may encounter unexpected behaviour if you try to roll back your changes.
tl;dr
Not all databases support nested transactions. Therefore, Rails will sometimes silently ignore a nested transaction and simply reuse the other transaction. However, a ActiveRecord::Rollback within the nested transaction will be caught by the block of the nested transaction. Therefore it will be ignored by the outer transaction, and not cause a roll back!
To avoid this unexpected ...
Workflow: How to use a key management service to encrypt passwords in the database
This is an extract from the linked article. It shows an approach on how to implement encrypted passwords with the AWS Key Management Service (KMS).
For most applications it's enough to use a hashed password with a salt (e.g. the gem devise defaults to this).
Upon password creation
-
Generate hash as hash of password + salt.
-
Encrypt the hash with a public key from KMS (you can store the public key in your server code).
-
In your database sto...
CSS variables aka CSS Custom Properties
CSS variables are very different from preprocessor variables. While preprocessors use variables to compile a static piece of CSS, CSS custom properties are a reactive (i.e. live) part of the styles. Think of them like usual CSS properties that cascade, but have:
- a special syntax: CSS variables always start with a double-dash (
--color) - no inherent meaning: Defining a CSS variable will not change any styles in itself
- a special functionality: CSS variables can be used within the values of other properties, including CSS variables...
HTML5: disabled vs. readonly form fields
Form fields can be rendered as noneditable by setting the disabled or the readonly attribute. Be aware of the differences:
disabled fields
- don’t post to the server
- don’t get focus
- are skipped while tab navigation
- available for
button,fieldset,input,select,textarea,command,keygen,optgroup,option
Browser specific behavior:
- IE 11: text inputs that are descendants of a disabled fieldset appear disabled but the user can still interact with them
- Firefox: selecting text in a disabled text field is no...
Jasmine: Adding custom matchers
Definition
A matcher is a function that returns an object with a compare key. Usually it is registered with beforeEach:
beforeEach ->
jasmine.addMatchers
# Example matcher
toBeAnything: ->
compare: (actualValue, matcherArguments...) ->
# Do some computations here ...
# Return whether the actualValue matches the expectation
pass: true
Usage
expect(actualValue).toBeAnything(matcherArguments...)
When a matcher is invoked, Jasmine will call its compare() fu...
Service Worker series by GoMakeThings
Learn how to create offline applications with service workers.
- The amazing power of service workers
- Writing your first service worker with vanilla JS
- Saving recently viewed pages offline with service workers and vanilla JS
- Offline first with service workers and vanilla JS
- Improving web font performance with service workers
- How to set an expiration date for items in a service worker cache
- How to update a service worker
- How to trigger a service worker function from the front end with vanilla JS
- How to immediately ...
Git: Advisory for cherry-picks to production branches
We often have a separate production branch that lags a bit behind the more cutting edge master branch. Sometimes you want to move some, but not all commits from master to production. This can be done with a git cherry-pick.
However, this may lead to considerable pain later, since git does not understand the commits are actually "the same". Hazards are unnecessary and hard to resolve conflicts as well as incorrect auto-merges.
In order to avoid this, always merge the production branch back to the master after the cherry-pick. ...
Tasks, microtasks, queues and schedules - JakeArchibald.com
The way that Javascript schedules timeouts and promise callbacks is more complicated than you think. This can be the reason why callbacks are not executed in the order that they are queued.
Please read this article!
This is an extract of the example in the article which demonstrates the execution order of tasks and microtasks.
console.log('script start');
setTimeout(function() {
console.log('setTimeout');
}, 0);
Promise.resolve().then(function() {
console.log('promise1');
}).then(function() {
console.log('promise2');
});
...
Disable automatic code suggestions in RubyMine
To disable the mostly useless automatic suggestion popups in RubyMine, go to File / Settings, then to Editor / General / Code Completion and uncheck Auto-display code completion.
You can still open the popup by pressing CTRL + Space. And you probably want to use Context-dependent word expansion instead, anyway.
How does Sentry group exceptions?
When you use Sentry to monitor exceptions, an important feature is Sentry's error grouping mechanism. This will aggregate similar error "events" into one issue, so you can track and monitor it more easily. Grouping is especially important when you try to silence certain errors.
It is worth understanding how Sentry's grouping mechanism works.
The default grouping mechanism
The exact algorithm has changed over time, and Sentry will keep using the algorithm that was active when you created the proj...