Remove description presence validation on collections (#38528)

app/models/collection.rb

@@ -36,11 +36,9 @@ class Collection < ApplicationRecord
   validates :name, length: { maximum: 40 }, if: :local?
   validates :name, length: { maximum: NAME_LENGTH_HARD_LIMIT }, if: :remote?
   validates :description,
-            presence: true,
             length: { maximum: 100 },
             if: :local?
   validates :description_html,
-            presence: true,
             length: { maximum: DESCRIPTION_LENGTH_HARD_LIMIT },
             if: :remote?
   validates :local, inclusion: [true, false]

app/serializers/rest/collection_serializer.rb

@@ -15,6 +15,7 @@ class REST::CollectionSerializer < ActiveModel::Serializer
 
   def description
     return object.description if object.local?
+    return if object.description_html.nil?
 
     Sanitize.fragment(object.description_html, Sanitize::Config::MASTODON_STRICT)
   end

spec/models/collection_spec.rb

@@ -10,8 +10,6 @@ RSpec.describe Collection do
 
     it { is_expected.to validate_length_of(:name).is_at_most(40) }
 
-    it { is_expected.to validate_presence_of(:description) }
-
     it { is_expected.to validate_length_of(:description).is_at_most(100) }
 
     it { is_expected.to_not allow_value(nil).for(:local) }
@@ -29,10 +27,6 @@ RSpec.describe Collection do
 
       it { is_expected.to validate_length_of(:name).is_at_most(Collection::NAME_LENGTH_HARD_LIMIT) }
 
-      it { is_expected.to_not validate_presence_of(:description) }
-
-      it { is_expected.to validate_presence_of(:description_html) }
-
       it { is_expected.to validate_length_of(:description_html).is_at_most(Collection::DESCRIPTION_LENGTH_HARD_LIMIT) }
 
       it { is_expected.to validate_presence_of(:uri) }

spec/requests/api/v1_alpha/collections_spec.rb

@@ -180,7 +180,6 @@ RSpec.describe 'Api::V1Alpha::Collections', feature: :collections do
           'error' => a_hash_including({
             'details' => a_hash_including({
               'name' => [{ 'error' => 'ERR_BLANK', 'description' => "can't be blank" }],
-              'description' => [{ 'error' => 'ERR_BLANK', 'description' => "can't be blank" }],
             }),
           }),
         })