Raise an ArgumentError when passing an invalid option to add_index

Closes #8104

3 files changed, 14 insertions, 1 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 1d43840573..da149dac54 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Raise an `ArgumentError` when passing an invalid option to `add_index`.
+
+    *Rafael Mendonça França*
+
 *   Fix `find_in_batches` crashing when IDs are strings and start option is not specified.
 
     *Alexis Bernard*
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 8790518d37..a606a5c775 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -617,11 +617,14 @@ module ActiveRecord
 
         def add_index_options(table_name, column_name, options = {})
           column_names = Array(column_name)
-          index_name   = index_name(table_name, :column => column_names)
+          index_name   = index_name(table_name, column: column_names)
 
           if Hash === options # legacy support, since this param was a string
+            options.assert_valid_keys(:unique, :order, :name, :where, :length)
+
             index_type = options[:unique] ? "UNIQUE" : ""
             index_name = options[:name].to_s if options.key?(:name)
+
             if supports_partial_index?
               index_options = options[:where] ? " WHERE #{options[:where]}" : ""
             end
diff --git a/activerecord/test/cases/migration/index_test.rb b/activerecord/test/cases/migration/index_test.rb
index dd9492924c..bfa275fee2 100644
--- a/activerecord/test/cases/migration/index_test.rb
+++ b/activerecord/test/cases/migration/index_test.rb
@@ -91,6 +91,12 @@ module ActiveRecord
         assert connection.index_exists?(:testings, [:foo, :bar])
       end
 
+      def test_valid_index_options
+        assert_raise ArgumentError do
+          connection.add_index :testings, :foo, unqiue: true
+        end
+      end
+
       def test_unique_index_exists
         connection.add_index :testings, :foo, :unique => true