asp: truncate the persphysique names attributes

Piggyback the `limit` option for ActiveModel's attribute method (which
might be a thing one day[1]) to chop the value of the string directly
on the XML-generating class.

This keeps the mapping classes in charge of translating our data into
the ASP stuff, semantically, but keeps the actual XML-maker in control
of the formatted length, which makes more sense to me: all the XML
tags have an associated length in the ASP documentation, so keeping it
as close as possible to the XML generation code is nicer.

It's also coherent with the custom :asp_date type which we use in a
couple places (ie: prestadoss.rb) and takes care of formatting a date
object in the format dictated by the ASP.

Closes #678.

[1]: rails/rails#51494

config/initializers/types.rb

@@ -8,4 +8,18 @@ def cast(value)
   end
 end
 
+module ActiveModel
+  module Type
+    class String
+      def cast(value)
+        if @limit
+          super(value.to_s.first(@limit))
+        else
+          super
+        end
+      end
+    end
+  end
+end
+
 ActiveModel::Type.register :asp_date, AspDateType

lib/asp/entities/pers_physique.rb

@@ -3,11 +3,14 @@
 module ASP
   module Entities
     class PersPhysique < Entity
+      FIRST_NAME_MAX_LENGTH = 20
+      LAST_NAME_MAX_LENGTH  = 50
+
       attribute :titre, :string
-      attribute :nomusage, :string
-      attribute :nomnaissance, :string
-      attribute :prenom, :string
-      attribute :datenaissance, :date
+      attribute :nomusage, :string, limit: LAST_NAME_MAX_LENGTH
+      attribute :nomnaissance, :string, limit: LAST_NAME_MAX_LENGTH
+      attribute :prenom, :string, limit: FIRST_NAME_MAX_LENGTH
+      attribute :datenaissance, :asp_date
       attribute :codeinseepaysnai, :string
       attribute :codeinseecommune, :string
 
@@ -27,7 +30,7 @@ def fragment(xml)
         xml.prenom(prenom)
         xml.nomusage(nomusage)
         xml.nomnaissance(nomnaissance)
-        xml.datenaissance(I18n.l(datenaissance, format: :asp))
+        xml.datenaissance(datenaissance)
         xml.codeinseepaysnai(codeinseepaysnai)
         xml.codeinseecommune(codeinseecommune) if born_in_france?
       end

spec/lib/asp/entities/pers_physique_spec.rb

@@ -15,6 +15,10 @@
   describe "validation" do
     subject(:model) { described_class.from_payment_request(payment_request) }
 
+    it_behaves_like "a limited string attribute", attribute: :prenom, length: 20
+    it_behaves_like "a limited string attribute", attribute: :nomnaissance, length: 50
+    it_behaves_like "a limited string attribute", attribute: :nomusage, length: 50
+
     context "when the student is born in France" do
       let(:student) { create(:student, :with_extra_info, :born_in_france) }
 

spec/support/shared/attribute_limiter.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+RSpec.shared_examples "a limited string attribute" do |attribute:, length:|
+  it "chops the '#{attribute}' attribute to #{length} characters" do
+    model.send "#{attribute}=", Faker::Alphanumeric.alpha(number: length + 1)
+
+    expect(model.send(attribute).to_s).to have(length).characters
+  end
+end