Add controller tests for switch_locale

This way it'll be easier to change it while checking we haven't broken
existing behavior.

While writing the tests, I noticed we were sometimes storing a symbol in
the session while sometimes we were storing a string. So we're adding a
`to_s` call so we always store a string in the session.

app/controllers/application_controller.rb

@@ -46,7 +46,7 @@ class ApplicationController < ActionController::Base
         current_user.update(locale: locale)
       end
 
-      session[:locale] = locale
+      session[:locale] = locale.to_s
       I18n.with_locale(locale, &action)
     end
 

app/controllers/management/base_controller.rb

@@ -41,10 +41,10 @@ class Management::BaseController < ActionController::Base
 
     def switch_locale(&action)
       if params[:locale] && I18n.available_locales.include?(params[:locale].to_sym)
-        session[:locale] = params[:locale]
+        session[:locale] = params[:locale].to_s
       end
 
-      session[:locale] ||= I18n.default_locale
+      session[:locale] ||= I18n.default_locale.to_s
 
       I18n.with_locale(session[:locale], &action)
     end

app/controllers/subscriptions_controller.rb

@@ -32,7 +32,7 @@ class SubscriptionsController < ApplicationController
 
     def set_user_locale(&action)
       if params[:locale].blank?
-        session[:locale] = I18n.available_locales.find { |locale| locale == @user.locale&.to_sym }
+        session[:locale] = I18n.available_locales.find { |locale| locale == @user.locale&.to_sym }.to_s
       end
       I18n.with_locale(session[:locale], &action)
     end

spec/controllers/application_controller_spec.rb

@@ -1,6 +1,14 @@
 require "rails_helper"
 
 describe ApplicationController do
+  controller do
+    skip_authorization_check
+
+    def index
+      render plain: I18n.locale
+    end
+  end
+
   describe "#current_budget" do
     it "returns the last budget that is not in draft phase" do
       create(:budget, :finished,  created_at: 2.years.ago, name: "Old")
@@ -12,4 +20,50 @@ describe ApplicationController do
       expect(budget.name).to eq("Current")
     end
   end
+
+  describe "#switch_locale" do
+    it "uses the default locale by default" do
+      get :index
+
+      expect(response.body).to eq "en"
+    end
+
+    it "uses the locale in the parameters when it's there" do
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+    end
+
+    it "uses the locale in the session if there are no parameters" do
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+
+      get :index
+
+      expect(response.body).to eq "es"
+    end
+
+    it "uses the locale in the parameters even when it's in the session" do
+      get :index
+
+      expect(response.body).to eq "en"
+
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+    end
+
+    context "authenticated user" do
+      let(:user) { create(:user) }
+      before { sign_in(user) }
+
+      it "updates the prefered locale when it's in the parameters" do
+        get :index, params: { locale: :es }
+
+        expect(user.reload.locale).to eq "es"
+        expect(response.body).to eq "es"
+      end
+    end
+  end
 end

spec/controllers/management/base_controller_spec.rb

@@ -1,6 +1,16 @@
 require "rails_helper"
 
 describe Management::BaseController do
+  before { session[:manager] = double }
+
+  controller do
+    skip_authorization_check
+
+    def index
+      render plain: I18n.locale
+    end
+  end
+
   describe "managed_user" do
     it "returns existent user with session document info if present" do
       session[:document_type] = "1"
@@ -21,4 +31,38 @@ describe Management::BaseController do
       expect(managed_user.document_number).to eq "333333333E"
     end
   end
+
+  describe "#switch_locale" do
+    it "uses the default locale by default" do
+      get :index
+
+      expect(response.body).to eq "en"
+    end
+
+    it "uses the locale in the parameters when it's there" do
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+    end
+
+    it "uses the locale in the session if there are no parameters" do
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+
+      get :index
+
+      expect(response.body).to eq "es"
+    end
+
+    it "uses the locale in the parameters even when it's in the session" do
+      get :index
+
+      expect(response.body).to eq "en"
+
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+    end
+  end
 end

spec/controllers/subscriptions_controller_spec.rb

@@ -19,5 +19,13 @@ describe SubscriptionsController do
       expect(response).to redirect_to "/"
       expect(flash[:alert]).to eq "No tienes permiso para acceder a esta página."
     end
+
+    it "uses the user locale where there's no locale in the parameters" do
+      create(:user, locale: "es", subscriptions_token: "mytoken")
+
+      get :edit, params: { token: "mytoken" }
+
+      expect(session[:locale]).to eq "es"
+    end
   end
 end