fix: resolve integer/enum types with limit in add_column

lib/active_record/connection_adapters/clickhouse/table_definition.rb

@@ -37,29 +37,7 @@ def initialize(
         end
 
         def integer(*args, **options)
-          # default to unsigned
-          unsigned = options[:unsigned]
-          unsigned = true if unsigned.nil?
-
-          kind = :uint32 # default
-
-          if options[:limit]
-            if unsigned
-              kind = :uint8       if options[:limit] == 1
-              kind = :uint16      if options[:limit] == 2
-              kind = :uint32      if [3,4].include?(options[:limit])
-              kind = :uint64      if [5,6,7].include?(options[:limit])
-              kind = :big_integer if options[:limit] == 8
-              kind = :uint256     if options[:limit] > 8
-            else
-              kind = :int8       if options[:limit] == 1
-              kind = :int16      if options[:limit] == 2
-              kind = :int32      if [3,4].include?(options[:limit])
-              kind = :int64     if options[:limit] > 5 && options[:limit] <= 8
-              kind = :int128     if options[:limit] > 8 && options[:limit] <= 16
-              kind = :int256     if options[:limit] > 16
-            end
-          end
+          kind = @conn.send(:resolve_integer_kind, options)
           args.each { |name| column(name, kind, **options.except(:limit, :unsigned)) }
         end
 

lib/active_record/connection_adapters/clickhouse_adapter.rb

@@ -413,6 +413,7 @@ def drop_function(name, options = {})
       end
 
       def add_column(table_name, column_name, type, **options)
+        type, options = resolve_type_with_limit(type, **options)
         with_settings(wait_end_of_query: 1, send_progress_in_http_headers: 1) { super }
       end
 
@@ -551,6 +552,52 @@ def change_column_for_alter(table_name, column_name, type, **options)
 
       private
 
+      # Resolves standard Rails types with :limit/:unsigned options into
+      # ClickHouse-specific types. This mirrors the logic in TableDefinition
+      # (integer, enum) so that add_column produces the same types as
+      # create_table.
+      def resolve_type_with_limit(type, **options)
+        case type.to_sym
+        when :integer
+          kind = resolve_integer_kind(options)
+          [kind, options.except(:limit, :unsigned)]
+        when :enum
+          kind = :enum8
+          kind = :enum8  if options[:limit] == 1
+          kind = :enum16 if options[:limit] == 2
+          [kind, options.except(:limit)]
+        else
+          [type, options]
+        end
+      end
+
+      def resolve_integer_kind(options)
+        unsigned = options[:unsigned]
+        unsigned = true if unsigned.nil?
+
+        kind = :uint32 # default
+
+        if options[:limit]
+          if unsigned
+            kind = :uint8       if options[:limit] == 1
+            kind = :uint16      if options[:limit] == 2
+            kind = :uint32      if [3, 4].include?(options[:limit])
+            kind = :uint64      if [5, 6, 7].include?(options[:limit])
+            kind = :big_integer if options[:limit] == 8
+            kind = :uint256     if options[:limit] > 8
+          else
+            kind = :int8   if options[:limit] == 1
+            kind = :int16  if options[:limit] == 2
+            kind = :int32  if [3, 4].include?(options[:limit])
+            kind = :int64  if options[:limit] >= 5 && options[:limit] <= 8
+            kind = :int128 if options[:limit] > 8 && options[:limit] <= 16
+            kind = :int256 if options[:limit] > 16
+          end
+        end
+
+        kind
+      end
+
       def connect
         @connection = @connection_parameters[:connection] || Net::HTTP.start(@connection_parameters[:host], @connection_parameters[:port], use_ssl: @connection_parameters[:ssl], verify_mode: OpenSSL::SSL::VERIFY_NONE)
 

spec/fixtures/migrations/dsl_add_column_with_limit/1_create_some_table.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class CreateSomeTable < ActiveRecord::Migration[7.1]
+  def up
+    create_table :some, options: 'MergeTree PARTITION BY toYYYYMM(date) ORDER BY (date)' do |t|
+      t.date :date, null: false
+    end
+  end
+end

spec/fixtures/migrations/dsl_add_column_with_limit/2_add_columns_with_limit.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class AddColumnsWithLimit < ActiveRecord::Migration[7.1]
+  def up
+    # Signed integers with limit
+    add_column :some, :int16_col, :integer, limit: 2, unsigned: false, null: false, default: 0
+    add_column :some, :int32_col, :integer, limit: 4, unsigned: false, null: false, default: 0
+    add_column :some, :int64_limit5_col, :integer, limit: 5, unsigned: false, null: false, default: 0
+    add_column :some, :int64_col, :integer, limit: 8, unsigned: false, null: false, default: 0
+
+    # Unsigned integers with limit
+    add_column :some, :uint8_col, :integer, limit: 1, null: false, default: 0
+    add_column :some, :uint16_col, :integer, limit: 2, null: false, default: 0
+    add_column :some, :uint64_col, :integer, limit: 8, null: false, default: 0
+
+    # Default unsigned integer (no limit)
+    add_column :some, :uint32_col, :integer, null: false, default: 0
+  end
+end

spec/single/migration_spec.rb

@@ -358,6 +358,29 @@
       end
     end
 
+    describe 'add column with limit' do
+      let(:directory) { 'dsl_add_column_with_limit' }
+      it 'adds integer columns with correct types based on limit and unsigned options' do
+        subject
+
+        current_schema = schema(model)
+
+        # Signed integers
+        expect(current_schema['int16_col'].sql_type).to eq('Int16')
+        expect(current_schema['int32_col'].sql_type).to eq('Int32')
+        expect(current_schema['int64_limit5_col'].sql_type).to eq('Int64')
+        expect(current_schema['int64_col'].sql_type).to eq('Int64')
+
+        # Unsigned integers
+        expect(current_schema['uint8_col'].sql_type).to eq('UInt8')
+        expect(current_schema['uint16_col'].sql_type).to eq('UInt16')
+        expect(current_schema['uint64_col'].sql_type).to eq('UInt64')
+
+        # Default unsigned integer (no limit)
+        expect(current_schema['uint32_col'].sql_type).to eq('UInt32')
+      end
+    end
+
     describe 'drop column' do
       let(:directory) { 'dsl_drop_column' }
       it 'drops column' do