[CIOPS-1082] Dynamic routing (#2)

### Description

This pull request changes the way the Engine is mounted, using an
initializer or default settings. This will allow us to change the
settings in case there's a conflict with the selected routing.

### Changes

* Mount the engine dynamically
* Reload routes for testing
* Updated the documentation

### Ticket

[CIOPS-1082](https://customink.atlassian.net/browse/CIOPS-1082)

Author: Arne De Herdt

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Is It Ready? CHANGELOG
 
+## 0.0.3
+* Make the mounting of the engine dynamic based upon the configuration
+
 ## 0.0.2
 * Enabled the CircleCI Pipeline
 * Added the test matrix

README.md

@@ -54,7 +54,6 @@ end
 With the above snippet, the health check will be available under:
 
 * https://your-domain/is_it_ready
-* https://your-domain/is_it_ready/is_it_ready
 
 ## Configuration
 
@@ -68,8 +67,7 @@ or conflicts with another plugin. In this case, creating an initializer under `c
 # Overwrite the endpoint that's used for listening to the required calls from the ReadinessProbe.
 # Setting this value, changes the second entry to be the path defined here, as well as the path under which
 # the application has been mounted:
-#   * https://your-domain/<mount-path>
-#   * https://your-domain/<mount-path>/something_else
+#   * https://your-domain/something_else
 # This is more for cosmetic purposes, or when mountain multiple engines under the same endpoint with distinct routes.
 ::IsItReady.endpoint = '/something_else'
 ```

config/routes.rb

@@ -4,6 +4,5 @@
 # This follows the same pattern as standard Ruby on Rails routing, but is scoped to
 # just the Rails Engine.
 ::IsItReady::Engine.routes.draw do
-  get ::IsItReady.endpoint => 'application#is_it_ready'
   root :to => 'application#is_it_ready'
 end

lib/is_it_ready/engine.rb

@@ -6,5 +6,13 @@ module IsItReady
   # how users will use this Engine in their applications.
   class Engine < ::Rails::Engine
     isolate_namespace IsItReady
+
+    # Initialize the engine dynamically based upon the configuration.
+    # This allows us to specify the configuration for the engine in the host application instead.
+    initializer 'add_routing_paths' do |app|
+      app.routes.append do
+        mount ::IsItReady::Engine => ::IsItReady.endpoint
+      end
+    end
   end
 end

lib/is_it_ready/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module IsItReady
-  VERSION = '0.0.2'
+  VERSION = '0.0.3'
 end

test/dummy/config/routes.rb

@@ -1,4 +1,3 @@
 Rails.application.routes.draw do
 
-  mount IsItReady::Engine => "/is_it_ready"
 end

test/integration/custom_navigation_test.rb

@@ -0,0 +1,30 @@
+require 'test_helper'
+
+module IsItReady
+  class CustomNavigationTest < ActionDispatch::IntegrationTest
+    include Engine.routes.url_helpers
+
+    setup do
+      ::IsItReady.endpoint = '/something_else'
+      Rails.application.reload_routes!
+    end
+
+    test('it returns the correct response status on the root') do
+      get root_url
+
+      assert_response :success
+    end
+
+    test('it returns the correct output on the root') do
+      get root_url
+
+      response = ::JSON.parse(@response.body, symbolize_names: true)
+
+      assert_equal({ :status => "ok", :code => 200 }, response)
+    end
+
+    test('it returns the not found response status on the default path') do
+      assert_raises(ActionController::RoutingError) { get DEFAULT_PATH }
+    end
+  end
+end

test/integration/navigation_test.rb

@@ -17,19 +17,5 @@ class NavigationTest < ActionDispatch::IntegrationTest
 
       assert_equal({ :status => "ok", :code => 200 }, response)
     end
-
-    test('it returns the correct response status on the default path') do
-      get DEFAULT_PATH
-
-      assert_response :success
-    end
-
-    test('it returns the correct output on the default path') do
-      get DEFAULT_PATH
-
-      response = ::JSON.parse(@response.body, symbolize_names: true)
-
-      assert_equal({ :status => "ok", :code => 200 }, response)
-    end
   end
 end