messagerie: better format message dates

app/helpers/commentaire_helper.rb

@@ -4,4 +4,10 @@ module CommentaireHelper
       "from-me"
     end
   end
+
+  def commentaire_date(commentaire)
+    is_current_year = (commentaire.created_at.year == Date.current.year)
+    template = is_current_year ? :message_date : :message_date_with_year
+    I18n.l(commentaire.created_at.localtime, format: template)
+  end
 end

app/views/shared/dossiers/messages/_message.html.haml

@@ -7,7 +7,7 @@
     - if ![user_email, commentaire.dossier.user.email, OLD_CONTACT_EMAIL, CONTACT_EMAIL].include?(commentaire.email)
       %span.guest Invité
     %span.date{ class: highlight_if_unseen_class(messagerie_seen_at, commentaire.created_at) }
-      = I18n.l(commentaire.created_at.localtime, format: '%d/%m/%Y à %H:%M ')
+      = commentaire_date(commentaire)
   .rich-text= sanitize(commentaire.body)
 
   - if commentaire.piece_justificative

config/locales/time_format.en.rb

@@ -0,0 +1,10 @@
+{
+  :en => {
+    :time => {
+      :formats => {
+        :message_date => lambda { |time, _| "%B #{time.day.ordinalize} at %H:%M" },
+        :message_date_with_year => lambda { |time, _| "%B #{time.day.ordinalize} %Y at %H:%M" }
+      }
+    }
+  }
+}

config/locales/time_format.fr.rb

@@ -0,0 +1,10 @@
+{
+  :fr => {
+    :time => {
+      :formats => {
+        :message_date => lambda { |time, _| "le #{time.day == 1 ? '1er' : time.day} %B à %H h %M" },
+        :message_date_with_year => lambda { |time, _| "le #{time.day == 1 ? '1er' : time.day} %B %Y à %H h %M" }
+      }
+    }
+  }
+}

spec/helpers/commentaire_helper_spec.rb

@@ -18,4 +18,34 @@ RSpec.describe CommentaireHelper, type: :helper do
       it { is_expected.to eq nil }
     end
   end
+
+  describe '.commentaire_date' do
+    let(:present_date) { Time.local(2018, 9, 2, 10, 5, 0) }
+    let(:creation_date) { present_date }
+    let(:commentaire) do
+      Timecop.freeze(creation_date) { create(:commentaire, email: "michel@pref.fr") }
+    end
+
+    subject do
+      Timecop.freeze(present_date) { commentaire_date(commentaire) }
+    end
+
+    it 'doesn’t include the creation year' do
+      expect(subject).to eq 'le 2 septembre à 10 h 05'
+    end
+
+    context 'when displaying a commentaire created on a previous year' do
+      let(:creation_date) { present_date.prev_year }
+      it 'includes the creation year' do
+        expect(subject).to eq 'le 2 septembre 2017 à 10 h 05'
+      end
+    end
+
+    context 'when formatting the first day of the month' do
+      let(:present_date) { Time.local(2018, 9, 1, 10, 5, 0) }
+      it 'includes the ordinal' do
+        expect(subject).to eq 'le 1er septembre à 10 h 05'
+      end
+    end
+  end
 end