[Fix #2604] Handle ProcedurePresentations that have gone invalid

app/models/assign_to.rb

@@ -4,6 +4,21 @@ class AssignTo < ApplicationRecord
   has_one :procedure_presentation, dependent: :destroy
 
   def procedure_presentation_or_default_and_errors
-    [procedure_presentation || build_procedure_presentation, nil]
+    errors = reset_procedure_presentation_if_invalid
+    [procedure_presentation || build_procedure_presentation, errors]
+  end
+
+  private
+
+  def reset_procedure_presentation_if_invalid
+    if procedure_presentation&.invalid?
+      # This is a last defense against invalid `ProcedurePresentation`s persistently
+      # hindering instructeurs. Whenever this gets triggered, it means that there is
+      # a bug somewhere else that we need to fix.
+
+      errors = procedure_presentation.errors
+      self.procedure_presentation = nil
+      errors
+    end
   end
 end

spec/models/assign_to_spec.rb

@@ -9,6 +9,7 @@ describe AssignTo, type: :model do
 
     context "without a procedure_presentation" do
       it { expect(procedure_presentation_or_default).not_to be_persisted }
+      it { expect(procedure_presentation_or_default).to be_valid }
       it { expect(errors).to be_nil }
     end
 
@@ -16,7 +17,24 @@ describe AssignTo, type: :model do
       let!(:procedure_presentation) { ProcedurePresentation.create(assign_to: assign_to) }
 
       it { expect(procedure_presentation_or_default).to eq(procedure_presentation) }
+      it { expect(procedure_presentation_or_default).to be_valid }
       it { expect(errors).to be_nil }
     end
+
+    context "with an invalid procedure_presentation" do
+      let!(:procedure_presentation) do
+        pp = ProcedurePresentation.new(assign_to: assign_to, displayed_fields: [{ 'table' => 'invalid', 'column' => 'random' }])
+        pp.save(validate: false)
+        pp
+      end
+
+      it { expect(procedure_presentation_or_default).not_to be_persisted }
+      it { expect(procedure_presentation_or_default).to be_valid }
+      it { expect(errors).to be_present }
+      it do
+        procedure_presentation_or_default
+        expect(assign_to.procedure_presentation).not_to be(procedure_presentation)
+      end
+    end
   end
 end

spec/models/gestionnaire_spec.rb

@@ -210,6 +210,17 @@ describe Gestionnaire, type: :model do
       it { expect(errors).to be_nil }
     end
 
+    context 'with invalid presentation' do
+      let(:procedure_id) { procedure.id }
+      before do
+        pp = ProcedurePresentation.create(assign_to: procedure_assign, displayed_fields: [{ 'table' => 'invalid', 'column' => 'random' }])
+        pp.save(:validate => false)
+      end
+
+      it { expect(procedure_presentation).not_to be_persisted }
+      it { expect(errors).to be_present }
+    end
+
     context 'with default presentation' do
       let(:procedure_id) { procedure_2.id }