Surface subscription validation errors instead of a generic message

On a failed create/update, show the actual validation messages (e.g. the doc trust-gate reason, or an invalid email-limit) via errors.full_messages, falling back to "Something went wrong" only when no message is present. Previously a user blocked by the <7-day doc gate through the controller saw a generic error and never the carefully-worded reason.

Author: schneems

app/controllers/repo_subscriptions_controller.rb

@@ -9,7 +9,7 @@ def create
       SendSingleTriageEmailJob.perform_later(@repo_subscription.id)
       redirect_to @repo_subscription.repo, notice: I18n.t("repo_subscriptions.subscribed")
     else
-      flash[:error] = "Something went wrong"
+      flash[:error] = @repo_subscription.errors.full_messages.to_sentence.presence || "Something went wrong"
       redirect_to repo_path(@repo_subscription.try(:repo) || Repo.find(repo_subscription_params[:repo_id]))
     end
   end
@@ -26,7 +26,7 @@ def update
     if @repo_sub.save
       flash[:success] = "Preferences updated!"
     else
-      flash[:error] = "Something went wrong"
+      flash[:error] = @repo_sub.errors.full_messages.to_sentence.presence || "Something went wrong"
     end
     redirect_to repo_path(@repo_sub.repo)
   end

test/functional/repo_subscriptions_controller_test.rb

@@ -22,6 +22,16 @@ class RepoSubscriptionsControllerTest < ActionController::TestCase
     assert_redirected_to repo_path(repo)
   end
 
+  test "blocked doc subscription surfaces the gate reason instead of a generic error" do
+    user = users(:mockstar)
+    user.update_column(:created_at, Time.current)
+    sign_in user
+    repo = repos(:no_subscribers)
+    post :create, params: {repo_subscription: {repo_id: repo.id, read: true, write: true, read_limit: 3, write_limit: 3}}
+    assert_includes flash[:error], "You can turn on docs once your account is 7 days old"
+    assert_redirected_to repo_path(repo)
+  end
+
   test "not update schneems' subscription when signed in as mockstar" do
     sign_in users(:mockstar)
     assert_raise ActiveRecord::RecordNotFound do
@@ -61,7 +71,7 @@ class RepoSubscriptionsControllerTest < ActionController::TestCase
     sign_in users(:schneems)
     patch :update, params: {id: repo_subscription.id,
                             repo_subscription: {email_limit: -1}}
-    assert_equal flash[:error], "Something went wrong"
+    assert_includes flash[:error], "must be greater than or equal to 0"
     assert_redirected_to repo_path(repo_subscription.repo)
   end