Don't expose `prepare_column_options`

This is only used for the internal `column_spec` and
`column_spec_for_primary_key`.

activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb

@@ -20,38 +20,6 @@ def column_spec_for_primary_key(column)
         spec
       end
 
-      # This can be overridden on an Adapter level basis to support other
-      # extended datatypes (Example: Adding an array option in the
-      # PostgreSQL::ColumnDumper)
-      def prepare_column_options(column)
-        spec = {}
-
-        if limit = schema_limit(column)
-          spec[:limit] = limit
-        end
-
-        if precision = schema_precision(column)
-          spec[:precision] = precision
-        end
-
-        if scale = schema_scale(column)
-          spec[:scale] = scale
-        end
-
-        default = schema_default(column) if column.has_default?
-        spec[:default] = default unless default.nil?
-
-        spec[:null] = "false" unless column.null
-
-        if collation = schema_collation(column)
-          spec[:collation] = collation
-        end
-
-        spec[:comment] = column.comment.inspect if column.comment.present?
-
-        spec
-      end
-
       # Lists the valid migration options
       def migration_keys # :nodoc:
         column_options_keys
@@ -59,6 +27,18 @@ def migration_keys # :nodoc:
       deprecate :migration_keys
 
       private
+        def prepare_column_options(column)
+          spec = {}
+          spec[:limit] = schema_limit(column)
+          spec[:precision] = schema_precision(column)
+          spec[:scale] = schema_scale(column)
+          spec[:default] = schema_default(column)
+          spec[:null] = "false" unless column.null
+          spec[:collation] = schema_collation(column)
+          spec[:comment] = column.comment.inspect if column.comment.present?
+          spec.compact!
+          spec
+        end
 
         def default_primary_key?(column)
           schema_type(column) == :bigint
@@ -98,6 +78,7 @@ def schema_scale(column)
         end
 
         def schema_default(column)
+          return unless column.has_default?
           type = lookup_cast_type_from_column(column)
           default = type.deserialize(column.default)
           if default.nil?

activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb

@@ -4,24 +4,23 @@ module ActiveRecord
   module ConnectionAdapters
     module MySQL
       module ColumnDumper # :nodoc:
-        def prepare_column_options(column)
-          spec = super
-          spec[:unsigned] = "true" if column.unsigned?
-
-          if supports_virtual_columns? && column.virtual?
-            spec[:as] = extract_expression_for_virtual_column(column)
-            spec[:stored] = "true" if /\b(?:STORED|PERSISTENT)\b/.match?(column.extra)
-            spec = { type: schema_type(column).inspect }.merge!(spec)
-          end
-
-          spec
-        end
-
         def migration_keys
           super + [:unsigned]
         end
 
         private
+          def prepare_column_options(column)
+            spec = super
+            spec[:unsigned] = "true" if column.unsigned?
+
+            if supports_virtual_columns? && column.virtual?
+              spec[:as] = extract_expression_for_virtual_column(column)
+              spec[:stored] = "true" if /\b(?:STORED|PERSISTENT)\b/.match?(column.extra)
+              spec = { type: schema_type(column).inspect }.merge!(spec)
+            end
+
+            spec
+          end
 
           def default_primary_key?(column)
             super && column.auto_increment? && !column.unsigned?

activerecord/lib/active_record/connection_adapters/postgresql/schema_dumper.rb

@@ -4,19 +4,17 @@ module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
       module ColumnDumper # :nodoc:
-        # Adds +:array+ option to the default set
-        def prepare_column_options(column)
-          spec = super
-          spec[:array] = "true" if column.array?
-          spec
-        end
-
         # Adds +:array+ as a valid migration key
         def migration_keys
           super + [:array]
         end
 
         private
+          def prepare_column_options(column)
+            spec = super
+            spec[:array] = "true" if column.array?
+            spec
+          end
 
           def default_primary_key?(column)
             schema_type(column) == :bigserial