Add media reaction unholding mutation

app/graphql/mutations/media_reaction.rb

@@ -5,4 +5,5 @@ class Mutations::MediaReaction < Mutations::Namespace
   field :unlike, mutation: Mutations::MediaReaction::Unlike
   field :create, mutation: Mutations::MediaReaction::Create
   field :delete, mutation: Mutations::MediaReaction::Delete
+  field :unhold, mutation: Mutations::MediaReaction::Update
 end

app/graphql/mutations/media_reaction/unhold.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+class Mutations::MediaReaction::Unhold < Mutations::Base
+  include FancyMutation
+
+  directive Directive::SitePermission, required: 'community_mod'
+
+  description 'Mark a held reaction as fine, unholding it.'
+
+  input do
+    argument :media_reaction_id, ID, required: true
+  end
+  result Types::Post
+  errors Types::Errors::NotAuthorized,
+    Types::Errors::NotAuthenticated,
+    Types::Errors::NotFound
+
+  def ready?(media_reaction_id:)
+    authenticate!
+    @reaction = MediaReaction.find_by(id: media_reaction_id)
+    return errors << Types::Errors::NotFound.build if @reaction.nil?
+    authorize!(@reaction, :unhold?)
+    true
+  end
+
+  def resolve(**)
+    @reaction.update!(hidden_at: nil)
+    @reaction
+  end
+end

app/policies/media_reaction_policy.rb

@@ -23,6 +23,8 @@ def destroy?
     record.try(:user) == user || can_administrate?
   end
 
+  def unhold? = can_administrate?
+
   class Scope < Scope
     def resolve
       return scope if can_administrate?