raise IrreversibleMigration if no column given

fixes #10419

Following code should raise  IrreversibleMigration. But the code was
failing since options is an array and not a hash.

def change
  change_table :users do |t|
    t.remove_index [:name, :email]
  end
end

Fix was to check if the options is a Hash before operating on it.

1 files changed, 28 insertions, 0 deletions

diff --git a/activerecord/test/cases/invertible_migration_test.rb b/activerecord/test/cases/invertible_migration_test.rb
index be59ffc4ab..0631871bd5 100644
--- a/activerecord/test/cases/invertible_migration_test.rb
+++ b/activerecord/test/cases/invertible_migration_test.rb
@@ -58,6 +58,24 @@ module ActiveRecord
       end
     end
 
+    class RemoveIndexMigration1 < SilentMigration
+      def self.up
+        create_table("horses") do |t|
+          t.column :name, :text
+          t.column :color, :text
+          t.index [:name, :color]
+        end
+      end
+    end
+
+    class RemoveIndexMigration2 < SilentMigration
+      def change
+        change_table("horses") do |t|
+          t.remove_index [:name, :color]
+        end
+      end
+    end
+
     class LegacyMigration < ActiveRecord::Migration
       def self.up
         create_table("horses") do |t|
@@ -104,6 +122,16 @@ module ActiveRecord
       end
     end
 
+    def test_exception_on_removing_index_without_column_option
+      RemoveIndexMigration1.new.migrate(:up)
+      migration = RemoveIndexMigration2.new
+      migration.migrate(:up)
+
+      assert_raises(IrreversibleMigration) do
+        migration.migrate(:down)
+      end
+    end
+
     def test_migrate_up
       migration = InvertibleMigration.new
       migration.migrate(:up)