[Fix #1016] display notifications for new messages

spec/helpers/dossier_helper_spec.rb

@@ -0,0 +1,28 @@
+require 'rails_helper'
+
+RSpec.describe DossierHelper, type: :helper do
+  describe ".highlight_if_unseen_class" do
+    let(:seen_at) { DateTime.now }
+
+    subject { highlight_if_unseen_class(seen_at, updated_at) }
+
+    context "when commentaire date is created before last seen datetime" do
+      let(:updated_at) { seen_at - 2.days }
+
+      it { is_expected.to eq nil }
+    end
+
+    context "when commentaire date is created after last seen datetime" do
+      let(:updated_at) { seen_at + 2.hours }
+
+      it { is_expected.to eq "highlighted" }
+    end
+
+    context "when there is no last seen datetime" do
+      let(:updated_at) { DateTime.now }
+      let(:seen_at) { nil }
+
+      it { is_expected.to eq nil }
+    end
+  end
+end