Merge pull request #10898 from mfo/US/navigation-accros-dossiers

ETQ instructeur, je peux passer au dossiers suivant ou au dossier précédent lorsque je visualise un dossiers d'un des onglet (a-suivre, tous, ...)

app/assets/stylesheets/buttons.scss

@@ -397,3 +397,7 @@ ul.dropdown-items {
     content: none !important;
   }
 }
+
+.back-btn {
+  line-height: 1.75rem;
+}

app/components/instructeurs/back_button_component.rb

@@ -6,6 +6,8 @@ class Instructeurs::BackButtonComponent < ApplicationComponent
   end
 
   def call
-    link_to "", @to, class: 'back-btn fr-btn fr-btn--secondary fr-btn--sm fr-mr-2w fr-icon-arrow-left-line', title: t('.back')
+    link_to @to, class: 'back-btn fr-btn fr-btn--secondary fr-btn--sm fr-mr-2w fr-px-1v', title: t('.back') do
+      dsfr_icon("fr-icon-arrow-left-line")
+    end
   end
 end

app/components/instructeurs/dossiers_navigation_component.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class Instructeurs::DossiersNavigationComponent < ApplicationComponent
+  attr_reader :dossier, :statut
+
+  def initialize(dossier:, procedure_presentation:, statut:)
+    @dossier = dossier
+    @cache = Cache::ProcedureDossierPagination.new(procedure_presentation: procedure_presentation, statut:)
+    @statut = statut
+  end
+
+  def back_url_options
+    options = { statut: }
+    options = options.merge(page: @cache.incoming_page) if @cache.incoming_page
+    options
+  end
+
+  def link_next
+    if has_next?
+      html_tag = :a
+      options = { class: "fr-link no-wrap fr-ml-3w", href: next_instructeur_dossier_path(dossier:, statut:) }
+    else
+      html_tag = :span
+      options = { class: "fr-link no-wrap fr-ml-3w fr-text-mention--grey" }
+    end
+
+    tag.send(html_tag, t('.next').html_safe + tag.span(class: 'fr-icon-arrow-right-line fr-ml-1w'), **options)
+  end
+
+  def link_previous
+    if has_previous?
+      html_tag = :a
+      options = { class: "fr-link no-wrap", href: previous_instructeur_dossier_path(dossier:, statut:) }
+    else
+      html_tag = :span
+      options = { class: "fr-link no-wrap fr-text-mention--grey" }
+    end
+
+    tag.send(html_tag, tag.span(class: 'fr-icon-arrow-left-line fr-mr-1w') + t('.previous'), **options)
+  end
+
+  def has_next? = @has_next ||= @cache.next_dossier_id(from_id: dossier.id).present?
+
+  def has_previous? = @has_previous ||= @cache.previous_dossier_id(from_id: dossier.id).present?
+end

app/components/instructeurs/dossiers_navigation_component/dossiers_navigation_component.en.yml

@@ -0,0 +1,4 @@
+---
+en:
+  next: Next file
+  previous: Previous file

app/components/instructeurs/dossiers_navigation_component/dossiers_navigation_component.fr.yml

@@ -0,0 +1,4 @@
+---
+fr:
+  next: Dossier suivant
+  previous: Dossier précédent

app/components/instructeurs/dossiers_navigation_component/dossiers_navigation_component.html.haml

@@ -0,0 +1,11 @@
+.flex.fr-mb-1w.align-start
+  = render Instructeurs::BackButtonComponent.new(to: instructeur_procedure_path(dossier.procedure, **back_url_options))
+
+  %h1.fr-h3.fr-mb-0
+    = t('show_dossier', scope: [:layouts, :breadcrumb], dossier_id: dossier.id, owner_name: dossier.owner_name)
+
+  .fr.ml-auto.align-center.flex.fr-mt-1v
+    = link_previous
+    = link_next
+
+= link_to dossier.procedure.libelle.truncate_words(10), instructeur_procedure_path(dossier.procedure), title: dossier.procedure.libelle, class: "fr-link"

app/controllers/concerns/instructeur_concern.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module InstructeurConcern
+  extend ActiveSupport::Concern
+
+  included do
+    def retrieve_procedure_presentation
+      @procedure_presentation ||= current_instructeur.procedure_presentation_for_procedure_id(params[:procedure_id])
+    end
+  end
+end

app/controllers/instructeurs/commentaires_controller.rb

@@ -2,10 +2,12 @@
 
 module Instructeurs
   class CommentairesController < ApplicationController
+    include InstructeurConcern
     before_action :authenticate_instructeur_or_expert!
     after_action :mark_messagerie_as_read
 
     def destroy
+      retrieve_procedure_presentation if current_instructeur
       if commentaire.sent_by?(current_instructeur) || commentaire.sent_by?(current_expert)
         commentaire.soft_delete!
 

app/controllers/instructeurs/dossiers_controller.rb

@@ -7,15 +7,16 @@ module Instructeurs
     include CreateAvisConcern
     include DossierHelper
     include TurboChampsConcern
-
+    include InstructeurConcern
     include ActionController::Streaming
     include Zipline
 
     before_action :redirect_on_dossier_not_found, only: :show
     before_action :redirect_on_dossier_in_batch_operation, only: [:archive, :unarchive, :follow, :unfollow, :passer_en_instruction, :repasser_en_construction, :repasser_en_instruction, :terminer, :restore, :destroy, :extend_conservation]
     before_action :set_gallery_attachments, only: [:show, :pieces_jointes, :annotations_privees, :avis, :messagerie, :personnes_impliquees, :reaffectation]
-    after_action :mark_demande_as_read, only: :show
+    before_action :retrieve_procedure_presentation, only: [:annotations_privees, :avis_new, :avis, :messagerie, :personnes_impliquees, :pieces_jointes, :reaffectation, :show, :dossier_labels, :passer_en_instruction, :repasser_en_construction, :repasser_en_instruction, :terminer, :pending_correction, :create_avis, :create_commentaire]
 
+    after_action :mark_demande_as_read, only: :show
     after_action :mark_messagerie_as_read, only: [:messagerie, :create_commentaire, :pending_correction]
     after_action :mark_avis_as_read, only: [:avis, :create_avis]
     after_action :mark_annotations_privees_as_read, only: [:annotations_privees, :update_annotations]
@@ -390,8 +391,40 @@ module Instructeurs
       @pieces_jointes_seen_at = current_instructeur.follows.find_by(dossier: dossier)&.pieces_jointes_seen_at
     end
 
+    def next
+      navigate_through_dossiers_list do |cache|
+        cache.next_dossier_id(from_id: params[:dossier_id])
+      end
+    end
+
+    def previous
+      navigate_through_dossiers_list do |cache|
+        cache.previous_dossier_id(from_id: params[:dossier_id])
+      end
+    end
+
     private
 
+    def navigate_through_dossiers_list
+      dossier = dossier_scope.find(params[:dossier_id])
+      procedure_presentation = current_instructeur.procedure_presentation_for_procedure_id(dossier.procedure.id)
+      cache = Cache::ProcedureDossierPagination.new(procedure_presentation:, statut: params[:statut])
+
+      next_or_previous_dossier_id = yield(cache)
+
+      if next_or_previous_dossier_id
+        redirect_to instructeur_dossier_path(procedure_id: procedure.id, dossier_id: next_or_previous_dossier_id, statut: params[:statut])
+      else
+        redirect_back fallback_location: instructeur_dossier_path(procedure_id: procedure.id, dossier_id: dossier.id, statut: params[:statut]), alert: "Une erreur est survenue"
+      end
+    rescue ActiveRecord::RecordNotFound
+      Sentry.capture_message(
+        "Navigation through dossier failed => ActiveRecord::RecordNotFound",
+        extra: { dossier_id: params[:dossier_id] }
+      )
+      redirect_to instructeur_procedure_path(procedure_id: procedure.id), alert: "Une erreur est survenue"
+    end
+
     def dossier_scope
       if action_name == 'update_annotations'
         Dossier

app/controllers/instructeurs/procedures_controller.rb

@@ -122,6 +122,8 @@ module Instructeurs
         .where(groupe_instructeurs: current_instructeur.groupe_instructeurs.where(procedure_id: @procedure.id))
         .where(seen_at: nil)
         .distinct
+
+      cache_show_procedure_state # don't move in callback, inherited by Instructeurs::DossiersController
     end
 
     def deleted_dossiers
@@ -392,5 +394,11 @@ module Instructeurs
     def ordered_procedure_ids_params
       params.require(:ordered_procedure_ids)
     end
+
+    def cache_show_procedure_state
+      cache = Cache::ProcedureDossierPagination.new(procedure_presentation:, statut:)
+
+      cache.save_context(ids: @filtered_sorted_paginated_ids, incoming_page: params[:page])
+    end
   end
 end

app/models/cache/procedure_dossier_pagination.rb

@@ -0,0 +1,102 @@
+# frozen_string_literal: true
+
+class Cache::ProcedureDossierPagination
+  HALF_WINDOW = 50
+  TRESHOLD_BEFORE_REFRESH = 1
+  CACHE_EXPIRACY = 8.hours
+
+  attr_reader :procedure_presentation, :statut, :cache
+  delegate :procedure, :instructeur, to: :procedure_presentation
+
+  def initialize(procedure_presentation:, statut:)
+    @procedure_presentation = procedure_presentation
+    @statut = statut
+    @cache = Kredis.json(cache_key, expires_in: CACHE_EXPIRACY)
+  end
+
+  def save_context(ids:, incoming_page:)
+    value = { ids: }
+    value[:incoming_page] = incoming_page if incoming_page
+    write_cache(value)
+  end
+
+  def next_dossier_id(from_id:)
+    index = ids&.index(from_id.to_i)
+
+    return nil if index.nil? # not found
+
+    if refresh_cache_after?(from_id:)
+      renew_ids(from_id:)
+      index = ids.index(from_id.to_i)
+    end
+    return nil if index.blank?
+    return nil if index + 1 > ids.size # out of bound end
+
+    ids[index + 1]
+  end
+
+  def previous_dossier_id(from_id:)
+    index = ids&.index(from_id.to_i)
+
+    return nil if index.nil? # not found
+
+    if refresh_cache_before?(from_id:)
+      renew_ids(from_id:)
+      index = ids.index(from_id.to_i)
+    end
+    return nil if index.blank?
+    return nil if index - 1 < 0 # out of bound start
+
+    ids[index - 1]
+  end
+
+  def incoming_page
+    read_cache[:incoming_page]
+  end
+
+  private
+
+  def cache_key
+    [procedure.id, instructeur.id, statut].join(":")
+  end
+
+  def write_cache(value)
+    cache.value = value
+    @read_cache = nil
+  end
+
+  def read_cache
+    @read_cache ||= Hash(cache.value).with_indifferent_access
+  end
+
+  def ids = read_cache[:ids]
+
+  def refresh_cache_after?(from_id:) = from_id.in?(ids.last(TRESHOLD_BEFORE_REFRESH))
+
+  def refresh_cache_before?(from_id:) = from_id.in?(ids.first(TRESHOLD_BEFORE_REFRESH))
+
+  def renew_ids(from_id:)
+    value = read_cache
+    value[:ids] = fetch_ids_around(from_id:)
+
+    write_cache(value)
+  end
+
+  def fetch_all_ids
+    dossiers = Dossier.where(groupe_instructeur_id: GroupeInstructeur.joins(:instructeurs, :procedure).where(procedure: procedure, instructeurs: [instructeur]).select(:id))
+    DossierFilterService.filtered_sorted_ids(dossiers, statut, procedure_presentation.filters_for(statut), procedure_presentation.sorted_column, instructeur, count: 0)
+  end
+
+  def fetch_ids_around(from_id:)
+    all_ids = fetch_all_ids
+    from_id_at = all_ids.index(from_id)
+
+    if from_id_at.present?
+      new_page_starts_at = [0, from_id_at - HALF_WINDOW].max # avoid index below 0
+      new_page_ends_at = [from_id_at + HALF_WINDOW, all_ids.size].min # avoid index above all_ids.size
+      all_ids.slice(new_page_starts_at, new_page_ends_at)
+    else
+      []
+    end
+  end
+end

app/models/instructeur.rb

@@ -127,12 +127,14 @@ class Instructeur < ApplicationRecord
     end
   end
 
+  def procedure_presentation_for_procedure_id(procedure_id)
+    assign_to = assign_to_for_procedure_id(procedure_id)
+    assign_to.procedure_presentation || assign_to.create_procedure_presentation!
+  end
+
   def procedure_presentation_and_errors_for_procedure_id(procedure_id)
-    assign_to
-      .joins(:groupe_instructeur)
-      .includes(:instructeur, :procedure)
-      .find_by(groupe_instructeurs: { procedure_id: procedure_id })
-      .procedure_presentation_or_default_and_errors
+    assign_to = assign_to_for_procedure_id(procedure_id)
+    assign_to.procedure_presentation_or_default_and_errors
   end
 
   def notifications_for_dossier(dossier)
@@ -355,4 +357,11 @@ class Instructeur < ApplicationRecord
       .merge(followed_dossiers)
       .with_notifications
   end
+
+  def assign_to_for_procedure_id(procedure_id)
+    assign_to
+      .joins(:groupe_instructeur)
+      .includes(:instructeur, :procedure)
+      .find_by(groupe_instructeurs: { procedure_id: procedure_id })
+  end
 end

app/views/instructeurs/commentaires/destroy.turbo_stream.haml

@@ -3,4 +3,4 @@
     = render Dossiers::MessageComponent.new(commentaire: @commentaire, connected_user: @commentaire.instructeur || @commentaire.expert)
 
   - if current_user.instructeur? && @commentaire.dossier_correction.present?
-    = turbo_stream.replace 'header-top', partial: 'instructeurs/dossiers/header_top', locals: { dossier: @commentaire.dossier }
+    = turbo_stream.replace 'header-top', partial: 'instructeurs/dossiers/header_top', locals: { dossier: @commentaire.dossier, procedure_presentation: @procedure_presentation }

app/views/instructeurs/dossiers/_header.html.haml

@@ -10,7 +10,7 @@
     locals: { steps: [[t('show_procedure', scope: [:layouts, :breadcrumb], libelle: dossier.procedure.libelle.truncate(22)), instructeur_procedure_path(dossier.procedure)],
                       [t('show_dossier', scope: [:layouts, :breadcrumb], dossier_id: dossier.id, owner_name: dossier.owner_name)]] }
 
-  = render partial: 'instructeurs/dossiers/header_top', locals: { dossier: }
+  = render partial: 'instructeurs/dossiers/header_top', locals: { dossier:, procedure_presentation: }
   = render partial: 'instructeurs/dossiers/header_bottom', locals: { dossier:, gallery_attachments: }
 
 .fr-container

app/views/instructeurs/dossiers/_header_top.html.haml

@@ -1,14 +1,9 @@
 #header-top.fr-container
-  .flex
+  = render Instructeurs::DossiersNavigationComponent.new(dossier:, procedure_presentation:, statut: params[:statut])
+
+  .flex.fr-mb-3w
     %div
-      .flex.fr-mb-1w
-        = render Instructeurs::BackButtonComponent.new(to: instructeur_procedure_path(dossier.procedure, statut: params[:statut]))
-        %h1.fr-h3.fr-mb-1w
-          = t('show_dossier', scope: [:layouts, :breadcrumb], dossier_id: dossier.id, owner_name: dossier.owner_name)
-
-
-      = link_to dossier.procedure.libelle.truncate_words(10), instructeur_procedure_path(dossier.procedure), title: dossier.procedure.libelle, class: "fr-link"
-      .fr-mt-2w.fr-badge-group
+      .fr-mt-2w.badge-group
         = procedure_badge(dossier.procedure)
 
         = status_badge(dossier.state)

app/views/instructeurs/dossiers/annotations_privees.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Annotations privées · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 #dossier-annotations-privees
   .fr-container

app/views/instructeurs/dossiers/avis.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Avis · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 .container
   .fr-grid-row

app/views/instructeurs/dossiers/avis_new.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Avis · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 .container
   .fr-grid-row

app/views/instructeurs/dossiers/change_state.turbo_stream.haml

@@ -1 +1 @@
-= turbo_stream.replace 'header-top', partial: 'header_top', locals: { dossier: @dossier }
+= turbo_stream.replace 'header-top', partial: 'header_top', locals: { dossier: @dossier, procedure_presentation: @procedure_presentation }

app/views/instructeurs/dossiers/messagerie.html.haml

@@ -1,5 +1,5 @@
 - content_for(:title, "Messagerie · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 = render partial: "shared/dossiers/messagerie", locals: { dossier: @dossier, connected_user: current_instructeur, messagerie_seen_at: @messagerie_seen_at , new_commentaire: @commentaire, form_url: commentaire_instructeur_dossier_path(@dossier.procedure, @dossier, statut: params[:statut]) }

app/views/instructeurs/dossiers/personnes_impliquees.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Personnes impliquées · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 .personnes-impliquees.container
   = render partial: 'instructeurs/dossiers/envoyer_dossier_block', locals: { dossier: @dossier, potential_recipients: @potential_recipients }

app/views/instructeurs/dossiers/pieces_jointes.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Pièces jointes")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 .fr-container
   .gallery.gallery-pieces-jointes{ "data-controller": "lightbox" }

app/views/instructeurs/dossiers/reaffectation.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Réaffectation · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 .container.groupe-instructeur
 

app/views/instructeurs/dossiers/show.html.haml

@@ -1,6 +1,6 @@
 - content_for(:title, "Demande · Dossier nº #{@dossier.id} (#{@dossier.owner_name})")
 
-= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments }
+= render partial: "header", locals: { dossier: @dossier, gallery_attachments: @gallery_attachments, procedure_presentation: @procedure_presentation }
 
 
 - if @dossier.etablissement&.as_degraded_mode?

app/views/instructeurs/procedures/_header.html.haml

@@ -1,5 +1,5 @@
 .procedure-header
-  .clipboard-container.flex
+  .align-start.flex
     = render Instructeurs::BackButtonComponent.new(to: instructeur_procedures_path)
     %h1.fr-h3.fr-mb-0
       = "#{procedure_libelle procedure} (n°#{procedure.id})"

config/routes.rb

@@ -485,6 +485,8 @@ Rails.application.routes.draw do
           resources :dossiers, only: [:show, :destroy], param: :dossier_id, path: "(:statut)/dossiers", defaults: { statut: 'a-suivre' } do
             member do
               resources :commentaires, only: [:destroy]
+              get 'next'
+              get 'previous'
               post 'repousser-expiration' => 'dossiers#extend_conservation'
               post 'repousser-expiration-and-restore' => 'dossiers#extend_conservation_and_restore'
               post 'dossier_labels' => 'dossiers#dossier_labels'

spec/controllers/instructeurs/dossiers_controller_spec.rb

@@ -984,6 +984,68 @@ describe Instructeurs::DossiersController, type: :controller do
     end
   end
 
+  describe 'navigation accross next/prev dossiers' do
+    let(:dossier_id) { dossier.id }
+    let(:statut) { 'a-suivre' }
+    let(:previous_dossier) { create(:dossier, :en_construction, procedure:) }
+    let(:next_dossier) { create(:dossier, :en_construction, procedure:) }
+    let(:cached_ids) { [previous_dossier, dossier, next_dossier].map(&:id) }
+    before do
+      cache = Cache::ProcedureDossierPagination.new(procedure_presentation: double(procedure:, instructeur:), statut:)
+      cache.save_context(incoming_page: 1, ids: cached_ids)
+    end
+
+    context 'when nexting' do
+      subject { get :next, params: { procedure_id: procedure.id, dossier_id: from_id, statut: } }
+
+      context 'when their is a next id' do
+        let(:from_id) { dossier.id }
+        it { is_expected.to redirect_to(instructeur_dossier_path(procedure_id: procedure.id, dossier_id: next_dossier.id)) }
+      end
+
+      context 'when their is not next id (en of list)' do
+        let(:from_id) { cached_ids.last }
+        it 'redirect on fallback location being current dossier and flashes an error' do
+          expect(subject).to redirect_to(instructeur_dossier_path(procedure_id: procedure.id, dossier_id: from_id))
+          expect(flash.alert).to eq("Une erreur est survenue")
+        end
+      end
+
+      context 'when id does not exists' do
+        let(:from_id) { 'kthxbye' }
+        it 'redirect on fallback location being current dossier and flashes an error' do
+          expect(subject).to redirect_to(instructeur_procedure_path(procedure_id: procedure.id))
+          expect(flash.alert).to eq("Une erreur est survenue")
+        end
+      end
+    end
+
+    context 'when previousing' do
+      subject { get :previous, params: { procedure_id: procedure.id, dossier_id: from_id, statut: } }
+
+      context 'when their is a previous id' do
+        let(:from_id) { dossier.id }
+        it { is_expected.to redirect_to(instructeur_dossier_path(procedure_id: procedure.id, dossier_id: previous_dossier.id)) }
+      end
+
+      context 'when their is not previous id (before list)' do
+        let(:from_id) { cached_ids.first }
+        it 'redirect on fallback location being current dossier and flashes an error' do
+          expect(subject).to redirect_to(instructeur_dossier_path(procedure_id: procedure.id, dossier_id: from_id))
+          expect(flash.alert).to eq("Une erreur est survenue")
+        end
+      end
+
+      context 'when id does not exists' do
+        let(:from_id) { 'kthxbye' }
+        it 'redirect on fallback location being current dossier and flashes an error' do
+          expect(subject).to redirect_to(instructeur_procedure_path(procedure_id: procedure.id))
+          expect(flash.alert).to eq("Une erreur est survenue")
+        end
+      end
+    end
+  end
+
   describe "#update_annotations" do
     let(:procedure) do
       create(:procedure, :published, types_de_champ_public:, types_de_champ_private:, instructeurs: instructeurs)

spec/controllers/instructeurs/procedures_controller_spec.rb

@@ -670,6 +670,18 @@ describe Instructeurs::ProceduresController, type: :controller do
         end
       end
     end
+
+    describe 'caches statut and page query param' do
+      let(:statut) { 'tous' }
+      let(:page) { '1' }
+      let!(:dossier) { create(:dossier, :accepte, procedure:) }
+      before { sign_in(instructeur.user) }
+      subject { get :show, params: { procedure_id: procedure.id, statut:, page: } }
+      it 'changes cached value' do
+        expect { subject }.to change { Cache::ProcedureDossierPagination.new(statut:, procedure_presentation: double(procedure:, instructeur:)).send(:read_cache) }
+          .from({}).to(ids: [dossier.id], incoming_page: page)
+      end
+    end
   end
 
   describe '#deleted_dossiers' do

spec/models/cache/procedure_dossier_pagination_spec.rb

@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+describe Cache::ProcedureDossierPagination do
+  let(:instructeur) { double(id: 1) }
+  let(:procedure) { double(id: 1) }
+  let(:procedure_presentation) { double(instructeur:, procedure:) }
+  let(:instance) { described_class.new(procedure_presentation:, statut: 'a-suivre') }
+
+  before do
+    instance.save_context(ids: cached_ids, incoming_page: nil)
+  end
+
+  describe 'next_dossier_id' do
+    context 'when procedure.dossiers.by_statut has only one page' do
+      let(:cached_ids) { [3, 4] }
+      before do
+        allow(instance).to receive(:fetch_all_ids).and_return(cached_ids)
+      end
+
+      it 'find next until the end' do
+        expect(instance.next_dossier_id(from_id: cached_ids.last)).to eq(nil)
+        expect(instance.next_dossier_id(from_id: cached_ids.first)).to eq(cached_ids.last)
+      end
+    end
+
+    context 'when procedure.dossiers.by_statut has more than one page' do
+      let(:cached_ids) { [2, 3, 4] }
+      let(:next_page_ids) { (0..10).to_a }
+
+      subject { instance.next_dossier_id(from_id: cached_ids.last) }
+      before do
+        allow(instance).to receive(:fetch_all_ids).and_return(next_page_ids)
+      end
+
+      it 'refreshes paginated_ids' do
+        expect { subject }.to change { instance.send(:ids) }.from(cached_ids).to(next_page_ids)
+      end
+    end
+
+    context 'when procedure.dossiers.by_statut does not include searched dossiers anymore' do
+      let(:cached_ids) { [] }
+      let(:next_page_ids) { [] }
+      before { allow(instance).to receive(:fetch_all_ids).and_return(next_page_ids) }
+
+      it 'works' do
+        expect(instance.next_dossier_id(from_id: 50)).to eq(nil)
+      end
+    end
+  end
+
+  describe 'previous_dossier_id' do
+    context 'when procedure.dossiers.by_statut has only one page' do
+      let(:cached_ids) { [3, 4] }
+      before do
+        allow(instance).to receive(:fetch_all_ids).and_return(cached_ids)
+      end
+
+      it 'find next until the end' do
+        expect(instance.previous_dossier_id(from_id: cached_ids.last)).to eq(cached_ids.first)
+        expect(instance.previous_dossier_id(from_id: cached_ids.first)).to eq(nil)
+      end
+    end
+
+    context 'when procedure.dossiers.by_statut has more than one page' do
+      let(:cached_ids) { [11, 12, 13] }
+      subject { instance.previous_dossier_id(from_id: cached_ids.first) }
+      let(:next_page_ids) { (11..20).to_a }
+      before do
+        allow(instance).to receive(:fetch_all_ids).and_return(next_page_ids)
+      end
+
+      it 'works' do
+        expect { subject }.to change { instance.send(:ids) }.from(cached_ids).to(next_page_ids)
+      end
+    end
+
+    context 'when procedure.dossiers.by_statut does not include searched dossiers anymore' do
+      let(:cached_ids) { [] }
+      before { allow(instance).to receive(:fetch_all_ids).and_return([]) }
+
+      it 'works' do
+        expect(instance.previous_dossier_id(from_id: 50)).to eq(nil)
+      end
+    end
+  end
+end

spec/views/instructeur/dossiers/annotations_privee.html.haml_spec.rb

@@ -3,12 +3,15 @@
 describe 'instructeurs/dossiers/annotations_privees', type: :view do
   let(:current_instructeur) { create(:instructeur) }
   let(:dossier) { create(:dossier, :en_construction) }
+  let(:procedure_presentation) { double(instructeur: current_instructeur, procedure: dossier.procedure) }
 
   before do
     sign_in(current_instructeur.user)
     allow(view).to receive(:current_instructeur).and_return(current_instructeur)
+
     allow(controller).to receive(:params).and_return({ statut: 'a-suivre' })
     assign(:dossier, dossier)
+    assign(:procedure_presentation, procedure_presentation)
   end
 
   subject { render }

spec/views/instructeur/dossiers/show.html.haml_spec.rb

@@ -3,12 +3,15 @@
 describe 'instructeurs/dossiers/show', type: :view do
   let(:current_instructeur) { create(:instructeur) }
   let(:dossier) { create(:dossier, :en_construction) }
+  let(:statut) { { statut: 'tous' } }
+  let(:procedure_presentation) { double(instructeur: current_instructeur, procedure: dossier.procedure) }
 
   before do
     sign_in(current_instructeur.user)
     allow(view).to receive(:current_instructeur).and_return(current_instructeur)
-    allow(controller).to receive(:params).and_return(statut: 'a-suivre')
+    allow(controller).to receive(:params).and_return(statut:)
     assign(:dossier, dossier)
+    assign(:procedure_presentation, procedure_presentation)
   end
 
   subject { render }
@@ -17,6 +20,12 @@ describe 'instructeurs/dossiers/show', type: :view do
     expect(subject).to have_text("Dossier nº #{dossier.id}")
   end
 
+  context 'when procedure statut / page was saved in session' do
+    it 'renders back button with saved state' do
+      expect(subject).to have_selector("a[href=\"#{instructeur_procedure_path(dossier.procedure, statut: statut)}\"]")
+    end
+  end
+
   it 'renders the dossier infos' do
     expect(subject).to have_text('Identité')
     expect(subject).to have_text('Demande')