From 83b185f52d575efaf46a58b0ab65702b1b1efa26 Mon Sep 17 00:00:00 2001
From: Earlopain <14981592+Earlopain@users.noreply.github.com>
Date: Wed, 21 Aug 2024 17:36:28 +0200
Subject: [PATCH] Fix an error for `Rails/BulkChangeTable` when the block for
 `change_table` is empty

---
 .../fix_error_rails_bulk_change_table.md      |  1 +
 lib/rubocop/cop/rails/bulk_change_table.rb    |  4 +--
 .../cop/rails/bulk_change_table_spec.rb       | 25 +++++++++++++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 changelog/fix_error_rails_bulk_change_table.md

diff --git a/changelog/fix_error_rails_bulk_change_table.md b/changelog/fix_error_rails_bulk_change_table.md
new file mode 100644
index 0000000000..3b01fd4dbe
--- /dev/null
+++ b/changelog/fix_error_rails_bulk_change_table.md
@@ -0,0 +1 @@
+* [#1335](https://github.com/rubocop/rubocop-rails/pull/1335): Fix an error for `Rails/BulkChangeTable` when the block for `change_table` is empty. ([@earlopain][])
diff --git a/lib/rubocop/cop/rails/bulk_change_table.rb b/lib/rubocop/cop/rails/bulk_change_table.rb
index 09a4b930f2..83ebb9b70e 100644
--- a/lib/rubocop/cop/rails/bulk_change_table.rb
+++ b/lib/rubocop/cop/rails/bulk_change_table.rb
@@ -140,9 +140,9 @@ def on_send(node)
           return unless support_bulk_alter?
           return unless node.command?(:change_table)
           return if include_bulk_options?(node)
-          return unless node.block_node
+          return unless (body = node.block_node&.body)
 
-          send_nodes = send_nodes_from_change_table_block(node.block_node.body)
+          send_nodes = send_nodes_from_change_table_block(body)
 
           add_offense_for_change_table(node) if count_transformations(send_nodes) > 1
         end
diff --git a/spec/rubocop/cop/rails/bulk_change_table_spec.rb b/spec/rubocop/cop/rails/bulk_change_table_spec.rb
index 28bd5b6ce6..931afb6b99 100644
--- a/spec/rubocop/cop/rails/bulk_change_table_spec.rb
+++ b/spec/rubocop/cop/rails/bulk_change_table_spec.rb
@@ -25,6 +25,25 @@ def change
     end
   end
 
+  shared_examples 'wrong arguments' do
+    it 'does not register an offense for `change_table` with no block' do
+      expect_no_offenses(<<~RUBY)
+        def up
+          change_table(:users)
+        end
+      RUBY
+    end
+
+    it 'does not register an offense for `change_table` with empty block' do
+      expect_no_offenses(<<~RUBY)
+        def up
+          change_table(:users) do
+          end
+        end
+      RUBY
+    end
+  end
+
   shared_examples 'no offense' do
     it 'does not register an offense when including combinable transformations' do
       expect_no_offenses(<<~RUBY)
@@ -45,6 +64,8 @@ def change
         end
       RUBY
     end
+
+    it_behaves_like 'wrong arguments'
   end
 
   shared_examples 'offense for mysql' do
@@ -91,6 +112,8 @@ def change
         end
       RUBY
     end
+
+    it_behaves_like 'wrong arguments'
   end
 
   shared_examples 'offense for postgresql' do
@@ -153,6 +176,8 @@ def change
         end
       RUBY
     end
+
+    it_behaves_like 'wrong arguments'
   end
 
   it_behaves_like 'no offense'