Limit length of full name during signup

If we don't validate for length, then signups that overflow the database
columns will unnecessarily create and cancel a tenant. Adding a
validation means we can avoid this.

app/models/signup.rb

@@ -8,6 +8,7 @@ class Signup
 
   validates :email_address, format: { with: URI::MailTo::EMAIL_REGEXP }, on: :identity_creation
   validates :full_name, :identity, presence: true, on: :completion
+  validates :full_name, length: { maximum: 240 }
 
   def initialize(...)
     super

app/views/signups/completions/new.html.erb

@@ -4,7 +4,7 @@
   <h1 class="txt-x-large font-weight-black margin-block-end"><%= @page_title %></h1>
 
   <%= form_with model: @signup, url: signup_completion_path, scope: "signup", class: "flex flex-column gap", data: { controller: "form" } do |form| %>
-    <%= form.text_field :full_name, class: "input txt-large", autocomplete: "name", placeholder: "Enter your full name…", autofocus: true, required: true %>
+    <%= form.text_field :full_name, class: "input txt-large", autocomplete: "name", placeholder: "Enter your full name…", autofocus: true, required: true, maxlength: 240 %>
 
     <p>You're one step away. Just enter your name to get your own Fizzy account.</p>
 

test/models/signup_test.rb

@@ -72,4 +72,17 @@ class SignupTest < ActiveSupport::TestCase
       assert_nil signup.user
     end
   end
+
+  test "#complete with name that is too long" do
+    Current.without_account do
+      signup = Signup.new(full_name: "A" * 241, identity: identities(:kevin))
+      signup.expects(:create_tenant).never
+
+      assert_not signup.complete
+
+      assert signup.errors[:full_name].any?
+      assert_nil signup.account
+      assert_nil signup.user
+    end
+  end
 end