fixes #18719 - replace usage of deprecated Fixnum constant

Most type checks for Fixnum can safely be replaced by Integer, as prior
to Ruby 2.4, Fixnum was a subclass of Integer and so the conditional
holds.

app/controllers/api/v2/external_usergroups_controller.rb

@@ -27,7 +27,7 @@ def show
       def_param_group :external_usergroup do
         param :external_usergroup, Hash, :required => true, :action_aware => true, :desc => N_('External user group information') do
           param :name, String, :required => true, :desc => N_('External user group name')
-          param :auth_source_id, Fixnum, :required => true, :desc => N_('ID of linked authentication source')
+          param :auth_source_id, :number, :required => true, :desc => N_('ID of linked authentication source')
         end
       end
 

app/controllers/api/v2/interfaces_controller.rb

@@ -38,9 +38,9 @@ def show
         param :ip6, String, :desc => N_("IPv6 address of interface")
         param :type, InterfaceTypeMapper::ALLOWED_TYPE_NAMES, :desc => N_("Interface type, e.g. bmc. Default is %{default_nic_type}")
         param :name, String, :desc => N_("Interface's DNS name")
-        param :subnet_id, Fixnum, :desc => N_("Foreman subnet ID of IPv4 interface")
-        param :subnet6_id, Fixnum, :desc => N_("Foreman subnet ID of IPv6 interface")
-        param :domain_id, Fixnum, :desc => N_("Foreman domain ID of interface. Required for primary interfaces on managed hosts.")
+        param :subnet_id, :number, :desc => N_("Foreman subnet ID of IPv4 interface")
+        param :subnet6_id, :number, :desc => N_("Foreman subnet ID of IPv6 interface")
+        param :domain_id, :number, :desc => N_("Foreman domain ID of interface. Required for primary interfaces on managed hosts.")
         param :identifier, String, :desc => N_("Device identifier, e.g. eth0 or eth1.1")
         param :managed, :bool, :desc => N_("Should this interface be managed via DHCP and DNS smart proxy and should it be configured during provisioning?")
         param :primary, :bool, :desc => N_("Should this interface be used for constructing the FQDN of the host? Each managed hosts needs to have one primary interface.")

app/models/config_report.rb

@@ -36,7 +36,7 @@ def self.report_status_column
   # it is not supported to edit status values after it has been written once.
   def status=(st)
     s = case st
-          when Integer, Fixnum
+          when Integer
             st
           when Hash
             ConfigReportStatusCalculator.new(:counters => st).calculate

app/services/authorizer.rb

@@ -181,6 +181,6 @@ def resource_name(klass)
   def base_ids
     raise ArgumentError, 'you must set base_collection to get base_ids' if @base_collection.nil?
 
-    @base_ids ||= @base_collection.all? { |i| i.is_a?(Fixnum) } ? @base_collection : @base_collection.map(&:id)
+    @base_ids ||= @base_collection.all? { |i| i.is_a?(Integer) } ? @base_collection : @base_collection.map(&:id)
   end
 end

lib/foreman/cast.rb

@@ -8,7 +8,7 @@ def self.to_bool(value)
         return false if value.blank? || value =~ (/\A(false|f|no|n|off|0)\z/i)
         return nil
 
-      when Fixnum
+      when Integer
         return true if value == 1
         return false if value == 0