Route: Change `#calculate_costs!` to `after_commit` callback

Use an `after_commit` instead of an `after_save`. The `after_save` could
cause intermittent problems due to Sidekiq starting before the
record/transaction actually gets committed to the database. In those
cases, the record wouldn't be found and cause an error.

With an `after_commit` callback, the record is sure to be committed
before Sidekiq takes over.

Additionally, limit the callback to `:create` and `:update` because
otherwise it will be active on `:destroy` by default also. This work
isn't relevant on destroy, so don't do it then.

Update the tests:

* Update labels
* Use `build` instead of `create` because we're saving the record at the
  end anyway so we don't need an object that starts out persisted
* Use `truncation: true` for these tests because otherwise the `commit`
  callback doesn't get called due to transactional teardown

Refs #6407

2 files changed, 7 insertions, 5 deletions

diff --git a/app/models/chouette/route.rb b/app/models/chouette/route.rb
index 14bfa47b6..9c722851f 100644
--- a/app/models/chouette/route.rb
+++ b/app/models/chouette/route.rb
@@ -77,7 +77,9 @@ module Chouette
     validates_presence_of :published_name
     validates_presence_of :line
     validates :wayback, inclusion: { in: self.wayback.values }
-    after_save :calculate_costs!, if: ->() { TomTom.enabled? }
+    after_commit :calculate_costs!,
+      on: [:create, :update],
+      if: ->() { TomTom.enabled? }
 
     def duplicate opposite=false
       overrides = {
diff --git a/spec/models/chouette/route/route_base_spec.rb b/spec/models/chouette/route/route_base_spec.rb
index 3d4a87791..43ff28c40 100644
--- a/spec/models/chouette/route/route_base_spec.rb
+++ b/spec/models/chouette/route/route_base_spec.rb
@@ -62,17 +62,17 @@ RSpec.describe Chouette::Route, :type => :model do
   end
 
   context "callbacks" do
-    it "calls #calculate_costs! after_save when TomTom is enabled" do
+    it "calls #calculate_costs! after_commit when TomTom is enabled", truncation: true do
       allow(TomTom).to receive(:enabled?).and_return(true)
-      route = create(:route)
+      route = build(:route)
 
       expect(route).to receive(:calculate_costs!)
       route.save
     end
 
-    it "doesn't call #calculate_costs! after_save if TomTom is disabled" do
+    it "doesn't call #calculate_costs! after_commit if TomTom is disabled", truncation: true do
       allow(TomTom).to receive(:enabled?).and_return(false)
-      route = create(:route)
+      route = build(:route)
 
       expect(route).not_to receive(:calculate_costs!)
       route.save