fix(exports): display exact number of dossiers count at time generation

app/models/export.rb

@@ -51,6 +51,7 @@ class Export < ApplicationRecord
   end
 
   def compute
+    self.dossiers_count = dossiers_for_export.count
     load_snapshot!
 
     file.attach(blob.signed_id) # attaching a blob directly might run identify/virus scanner and wipe it
@@ -109,9 +110,10 @@ class Export < ApplicationRecord
   end
 
   def count
-    if procedure_presentation_id.present?
-      dossiers_for_export.count
-    end
+    return dossiers_count if !dossiers_count.nil? # export generated
+    return dossiers_for_export.count if procedure_presentation_id.present?
+
+    nil
   end
 
   def procedure

spec/components/dossiers/export_link_component_spec.rb

@@ -1,17 +1,19 @@
 RSpec.describe Dossiers::ExportLinkComponent, type: :component do
   let(:procedure) { create(:procedure) }
-  let(:groupe_instructeur) { create(:groupe_instructeur, procedure: procedure) }
-  let(:export) { create(:export, groupe_instructeurs: [groupe_instructeur], updated_at: 5.minutes.ago, created_at: 10.minutes.ago) }
+  let(:groupe_instructeur) { create(:groupe_instructeur, procedure: procedure, instructeurs: [build(:instructeur)]) }
   let(:export_url) { double("ExportUrl", call: "/some/fake/path") }
 
+  let(:assign_to) { create(:assign_to, procedure: procedure, instructeur: groupe_instructeur.instructeurs.first) }
+  let(:procedure_presentation) { create(:procedure_presentation, procedure: procedure, assign_to: assign_to) }
+
   let(:component) { described_class.new(procedure:, exports: [export], export_url:) }
 
   describe "rendering" do
     subject { render_inline(component).to_html }
 
     context "when the export is available" do
+      let(:export) { create(:export, :generated, groupe_instructeurs: [groupe_instructeur], updated_at: 5.minutes.ago, created_at: 10.minutes.ago) }
       before do
-        allow(export).to receive(:available?).and_return(true)
         attachment = ActiveStorage::Attachment.new(name: "export", record: export, blob: ActiveStorage::Blob.new(byte_size: 10.kilobytes, content_type: "text/csv", filename: "export.csv"))
         allow(export).to receive(:file).and_return(attachment)
       end
@@ -25,12 +27,29 @@ RSpec.describe Dossiers::ExportLinkComponent, type: :component do
         expect(subject).to include("CSV")
         expect(subject).to include("10 ko")
       end
+
+      context 'when export is for everything' do
+        it 'not display the exact dossiers count' do
+          expect(subject).to include("tous les dossiers")
+        end
+      end
+
+      context 'when export is for a presentation' do
+        before do
+          export.update!(procedure_presentation: procedure_presentation)
+        end
+
+        it 'display the persisted dossiers count' do
+          expect(subject).to include("10 dossiers")
+        end
+      end
     end
 
     context "when the export is not available" do
+      let(:export) { create(:export, :pending, groupe_instructeurs: [groupe_instructeur], procedure_presentation: procedure_presentation, created_at: 10.minutes.ago) }
+
       before do
-        allow(export).to receive(:available?).and_return(false)
-        allow(export).to receive(:failed?).and_return(false)
+        create_list(:dossier, 3, :en_construction, procedure: procedure, groupe_instructeur: groupe_instructeur)
       end
 
       it "displays the pending label" do
@@ -40,12 +59,14 @@ RSpec.describe Dossiers::ExportLinkComponent, type: :component do
       it "displays a refresh page button" do
         expect(subject).to include("Recharger")
       end
+
+      it 'displays the current dossiers count' do
+        expect(subject).to include("3 dossiers")
+      end
     end
 
     context "when the export has failed" do
-      before do
-        allow(export).to receive(:failed?).and_return(true)
-      end
+      let(:export) { create(:export, :failed) }
 
       it "displays the refresh old export button" do
         expect(subject).to include("Regénérer")

spec/models/export_spec.rb

@@ -198,4 +198,31 @@ RSpec.describe Export, type: :model do
       expect(results.count).to eq(1)
     end
   end
+
+  describe '.dossiers_count' do
+    let(:export) { create(:export, :pending) }
+
+    before do
+      blob_double = instance_double("ActiveStorage::Blob", signed_id: "some_signed_id_value")
+      attachment_double = instance_double("ActiveStorage::Attached::One", attach: true)
+
+      allow(export).to receive(:blob).and_return(blob_double)
+      allow(export).to receive(:file).and_return(attachment_double)
+
+      create_list(:dossier, 3, :en_construction, groupe_instructeur: export.groupe_instructeurs.first)
+    end
+
+    it 'is not set until generation' do
+      expect(export.dossiers_count).to be_nil
+    end
+
+    it 'is persisted after generation' do
+      export.compute_with_safe_stale_for_purge do
+        export.compute
+      end
+
+      export.reload
+      expect(export.dossiers_count).to eq(3)
+    end
+  end
 end