Migration generators use `change` even for destructive methods [#8267]

activerecord/lib/rails/generators/active_record/migration/templates/migration.rb

@@ -21,28 +21,16 @@ def change
     end
   end
 <%- else -%>
-  def up
+  def change
 <% attributes.each do |attribute| -%>
 <%- if migration_action -%>
   <%- if attribute.reference? -%>
-    remove_reference :<%= table_name %>, :<%= attribute.name %><%= ', polymorphic: true' if attribute.polymorphic? %>
+    remove_reference :<%= table_name %>, :<%= attribute.name %><%= attribute.inject_options %>
   <%- else -%>
-    remove_column :<%= table_name %>, :<%= attribute.name %>
-  <%- end -%>
-<%- end -%>
-<%- end -%>
-  end
-
-  def down
-<% attributes.reverse.each do |attribute| -%>
-<%- if migration_action -%>
-  <%- if attribute.reference? -%>
-    add_reference :<%= table_name %>, :<%= attribute.name %><%= attribute.inject_options %>
-  <%- else -%>
-    add_column :<%= table_name %>, :<%= attribute.name %>, :<%= attribute.type %><%= attribute.inject_options %>
     <%- if attribute.has_index? -%>
-    add_index :<%= table_name %>, :<%= attribute.index_name %><%= attribute.inject_index_options %>
+    remove_index :<%= table_name %>, :<%= attribute.index_name %><%= attribute.inject_index_options %>
     <%- end -%>
+    remove_column :<%= table_name %>, :<%= attribute.name %>, :<%= attribute.type %><%= attribute.inject_options %>
   <%- end -%>
 <%- end -%>
 <%- end -%>

railties/test/generators/migration_generator_test.rb

@@ -53,15 +53,10 @@ def test_remove_migration_with_indexed_attribute
     run_generator [migration, "title:string:index", "body:text"]
 
     assert_migration "db/migrate/#{migration}.rb" do |content|
-      assert_method :up, content do |up|
-        assert_match(/remove_column :posts, :title/, up)
-        assert_match(/remove_column :posts, :body/, up)
-      end
-
-      assert_method :down, content do |down|
-        assert_match(/add_column :posts, :title, :string/, down)
-        assert_match(/add_column :posts, :body, :text/, down)
-        assert_match(/add_index :posts, :title/, down)
+      assert_method :change, content do |change|
+        assert_match(/remove_column :posts, :title, :string/, change)
+        assert_match(/remove_column :posts, :body, :text/, change)
+        assert_match(/remove_index :posts, :title/, change)
       end
     end
   end
@@ -71,14 +66,9 @@ def test_remove_migration_with_attributes
     run_generator [migration, "title:string", "body:text"]
 
     assert_migration "db/migrate/#{migration}.rb" do |content|
-      assert_method :up, content do |up|
-        assert_match(/remove_column :posts, :title/, up)
-        assert_match(/remove_column :posts, :body/, up)
-      end
-
-      assert_method :down, content do |down|
-        assert_match(/add_column :posts, :title, :string/, down)
-        assert_match(/add_column :posts, :body, :text/, down)
+      assert_method :change, content do |change|
+        assert_match(/remove_column :posts, :title, :string/, change)
+        assert_match(/remove_column :posts, :body, :text/, change)
       end
     end
   end
@@ -88,14 +78,9 @@ def test_remove_migration_with_references_options
     run_generator [migration, "author:belongs_to", "distributor:references{polymorphic}"]
 
     assert_migration "db/migrate/#{migration}.rb" do |content|
-      assert_method :up, content do |up|
-        assert_match(/remove_reference :books, :author/, up)
-        assert_match(/remove_reference :books, :distributor, polymorphic: true/, up)
-      end
-
-      assert_method :down, content do |down|
-        assert_match(/add_reference :books, :author, index: true/, down)
-        assert_match(/add_reference :books, :distributor, polymorphic: true, index: true/, down)
+      assert_method :change, content do |change|
+        assert_match(/remove_reference :books, :author, index: true/, change)
+        assert_match(/remove_reference :books, :distributor, polymorphic: true, index: true/, change)
       end
     end
   end
@@ -192,12 +177,8 @@ def test_should_create_empty_migrations_if_name_not_start_with_add_or_remove
     run_generator [migration, "title:string", "content:text"]
 
     assert_migration "db/migrate/#{migration}.rb" do |content|
-      assert_method :up, content do |up|
-        assert_match(/^\s*$/, up)
-      end
-
-      assert_method :down, content do |down|
-        assert_match(/^\s*$/, down)
+      assert_method :change, content do |change|
+        assert_match(/^\s*$/, change)
       end
     end
   end