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Rails

A collection of 9 posts

6 tips to ensure your rake task runs smoothly

6 tips to ensure your rake task runs smoothly

Rake is a task runner/task management tool in Ruby. You can create diverse tasks, put tasks in the Rakefile, and execute a command like rake :your_awesome_task. Your task will start running by Rake. In Ruby, you can put task code inside a file named Rakefile, rakefile, Rakefile.

How to Benchmark my code in Ruby or Rails

How to Benchmark my code in Ruby or Rails

Recently, I had a job to fix the slow code. Before diving into fixing the slow code, I used Scout APM to identify the performance bottlenecks, which helped me make sure where the slow code is. To prove the new optimization solution is faster, in addition to checking the before-after

Lessons learned from failing to access an environment variable in YMAL file

Lessons learned from failing to access an environment variable in YMAL file

Note: The following was tested with Ruby 2.6.6 / Rails 5.2.6. Situation I tried to add an environment variable in the application.yml file. # config/application.yml default: #... API_TOKEN: ABC123456 And I expected when executing ENV['API_TOKEN'] in Rails console, I would get ABC123456. But

How to use and test an AJAX request in Rails

How to use and test an AJAX request in Rails

What's AJAX? AJAX (Asynchronous Javascript and XML) is a kind of technique that can send HTTP requests and exchange data with a server by Javascript. It's an important and practical technique to enhance the user experience, especially when we want to achieve the effect that updating the partial content and

Play with nil

What's nil? nil is an instance of NilClass. It's a special Ruby object used to represent the absence of any value. And it also behaves like false when used in a conditional statement. What's more, there is only one nil object, whose object_id is always 8 (in 64-bit Ruby)

3 helpful methods in Rails console

3 helpful methods in Rails console

Recently, I start reading Practicing Rails [https://www.justinweiss.com/practicing-rails/]. I love the main point in chapter 1: Rails console is a good place to experiment with our ideas. There are 3 tips to explore ideas through the Rails console I learned from Practicing Rails. 1. Use app object.

RSpec - Use shared_examples to avoid duplicate test examples

RSpec - Use shared_examples to avoid duplicate test examples

It's common to see a before_action method that need executing in different controller actions. At the same time, when writing RSpec tests for these actions, it's easily to write down context blocks whose test examples are almost the same, and only a let declaration is different. The code might

What's the difference between find_each, find_in_batches, in_batches in Rails?

What's the difference between find_each, find_in_batches, in_batches in Rails?

Sometimes we will use klass_name.all to get records from the database. That’ll be ok, if we only have 100 records in the database. However, using klass_name.all might not be the best way to get records, especially when we need to query large numbers of records.

Before adding a new validation, one thing you should notice

Before adding a new validation, one thing you should notice

When we develop a new feature, it's common to add a new column that needs some validations in the model. So, we might write something like this: class Book < ApplicationRecord #... validates :barcode, presence: true end To increase the test coverage, adding the test example is necessary: RSpec.describe Book, type: