Feature flag

[byhbt]

Problem:

When release new features, however the customer want hide it for some purpose:

• Testing
• For specific user
• Event days

Solution:

Define variable in env.
Use that flag to control the logic.

NEW_REGISTRATION_ENABLED: false
AWESOME_FEATURE_ENABLED: false

Lesson:

https://jeroenmols.com/blog/2019/08/13/featureflags

[byhbt]

How to test feature flag:

For example, we have a route: /sign-up.

Now we have to replace the existing logic code base by another login.

SignUpController will be replaced by NewSignUpController

The problem: there is one route, in the test environment it will be failed. We still have to write test for the new code base, also keep the existing same code base and specs.

Solution:

require 'rails_helper'

RSpec.describe SignUpsController, type: :controller do
  before do
    @request.env['devise.mapping'] = Devise.mappings[:user]

    Rails.application.routes.draw do
      devise_for :users, controllers: { registrations: 'new_sign_ups' }
    end
  end

  describe 'GET#new' do
    it 'renders new view' do
      get :new

      expect(response).to have_http_status :ok
      expect(response).to render_template :new
    end
  end

  after do
    Rails.application.reload_routes!
  end
end

[byhbt]

Why we need mapping:

@request.env['devise.mapping'] = Devise.mappings[:user]

est.env["devise