Implement ClientConfigurationsController for mobile client path config.

app/controllers/client_configurations_controller.rb

@@ -0,0 +1,15 @@
+class ClientConfigurationsController < ApplicationController
+  skip_before_action :require_account, :require_authentication
+  allow_unauthorized_access
+
+  def show
+    expires_in 1.minute, public: true
+
+    render action: client_configuration_name
+  end
+
+  private
+    def client_configuration_name
+      "#{params.require(:platform)}_v#{params.require(:version)}"
+    end
+end

test/controllers/client_configurations_controller_test.rb

@@ -0,0 +1,47 @@
+require "test_helper"
+
+class ClientConfigurationsControllerTest < ActionDispatch::IntegrationTest
+  test "android" do
+    assert_ok "/client_configurations/android_v1.json"
+  end
+
+  test "ios" do
+    assert_ok "/client_configurations/ios_v1.json"
+  end
+
+  test "bad platform" do
+    assert_no_route "/client_configurations/blackberry_v1.json"
+  end
+
+  test "bad version" do
+    assert_no_route "/client_configurations/android_va.json"
+  end
+
+  test "nonexistent version" do
+    assert_missing "/client_configurations/android_v2000.json"
+    assert_missing "/client_configurations/ios_v2000.json"
+  end
+
+  private
+    def assert_ok(url, cache_control: { public: true, max_age: "60" })
+      get url
+      assert_response :ok
+
+      assert_kind_of Hash, response.parsed_body["settings"]
+      assert_kind_of Array, response.parsed_body["rules"]
+
+      assert_equal cache_control, response.cache_control
+    end
+
+    def assert_no_route(url)
+      without_action_dispatch_exception_handling do
+        assert_raises(ActionController::RoutingError) { get url }
+      end
+    end
+
+    def assert_missing(url)
+      without_action_dispatch_exception_handling do
+        assert_raises(ActionView::MissingTemplate) { get url }
+      end
+    end
+end