Revert instructions for removing a column with NOT NULL and no defaul…

…t value - #197

CHANGELOG.md

@@ -2,7 +2,6 @@
 
 - Added `skip_databases` option
 - Added warning for unsupported adapters
-- Improved instructions for removing a column with `NOT NULL` and no default value
 - Improved output for `db:forward`, `db:rollback`, `db:migrate:up`, and `db:migrate:down`
 
 ## 2.0.2 (2024-10-30)

README.md

@@ -129,16 +129,6 @@ end
 4. Deploy and run the migration
 5. Remove the line added in step 1
 
-Note: For columns with `NOT NULL` and no default value, remove `NOT NULL` before any other steps.
-
-```ruby
-class RemoveNotNull < ActiveRecord::Migration[7.2]
-  def change
-    change_column_null :users, :some_column, true
-  end
-end
-```
-
 ### Changing the type of a column
 
 #### Bad

lib/strong_migrations/checks.rb

@@ -319,19 +319,11 @@ def check_remove_column(method, *args)
 
       code = "self.ignored_columns += #{columns.map(&:to_s).inspect}"
 
-      table_columns = connection.columns(args[0]).index_by(&:name) rescue {}
-      null_columns = columns.select { |c| table_columns[c.to_s] && !table_columns[c.to_s].null && table_columns[c.to_s].default.nil? }
-      if null_columns.any?
-        commands = null_columns.map { |c| command_str(:change_column_null, [args[0], c, true]) }
-        null_code = "First, remove NOT NULL:\n\nclass RemoveNotNull < ActiveRecord::Migration#{migration_suffix}\n  def change\n    #{commands.join("\n    ")}\n  end\nend\n\nDeploy and run the migration. "
-      end
-
       raise_error :remove_column,
         model: model_name(args[0]),
         code: code,
         command: command_str(method, args),
-        column_suffix: columns.size > 1 ? "s" : "",
-        null_code: null_code
+        column_suffix: columns.size > 1 ? "s" : ""
     end
 
     def check_remove_index(*args)

lib/strong_migrations/error_messages.rb

@@ -61,7 +61,7 @@ def change
 "Changing the type is safe, but setting NOT NULL is not.",
 
     remove_column: "Active Record caches attributes, which causes problems
-when removing columns. %{null_code}Ignore the column%{column_suffix}:
+when removing columns. Be sure to ignore the column%{column_suffix}:
 
 class %{model} < %{base_model}
   %{code}

test/migrations/remove_column.rb

@@ -39,15 +39,3 @@ def change
     remove_belongs_to :users, :device
   end
 end
-
-class RemoveColumnNull < TestMigration
-  def change
-    remove_column :devices, :name, :string
-  end
-end
-
-class RemoveColumnsNull < TestMigration
-  def change
-    remove_columns :devices, :name, :city, :country
-  end
-end

test/remove_column_test.rb

@@ -28,12 +28,4 @@ def test_remove_reference_polymorphic
   def test_remove_belongs_to
     assert_unsafe RemoveBelongsTo
   end
-
-  def test_remove_column_null
-    assert_unsafe RemoveColumnNull
-  end
-
-  def test_remove_columns_null
-    assert_unsafe RemoveColumnsNull
-  end
 end

test/test_helper.rb

@@ -93,9 +93,6 @@ def connection_class
   end
 
   create_table :devices do |t|
-    t.string :name, null: false
-    t.string :city, null: false
-    t.string :country, null: false, default: ""
   end
 end