Deprecate passing default to index_name_exists?

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Deprecate passing `default` to `index_name_exists?`.
+
+    *Ryuta Kamizono*
+
 *   PostgreSQL: schema dumping support for interval and OID columns.
 
     *Ryuta Kamizono*
@@ -12,7 +16,7 @@
 
     *namusyaka*
 
-*   Allow ActiveRecord::Base#as_json to be passed a frozen Hash.
+*   Allow `ActiveRecord::Base#as_json` to be passed a frozen Hash.
 
     *Isaac Betesh*
 
@@ -32,9 +36,9 @@
 
     *Ryuta Kamizono*
 
-*   Fix `association_primary_key_type` for reflections with symbol primary key
+*   Fix `association_primary_key_type` for reflections with symbol primary key.
 
-    Fixes #27864
+    Fixes #27864.
 
     *Daniel Colson*
 

activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

@@ -774,6 +774,11 @@ module ActiveRecord
 
       # Verifies the existence of an index with a given name.
       def index_name_exists?(table_name, index_name, default = nil)
+        unless default.nil?
+          ActiveSupport::Deprecation.warn(<<-MSG.squish)
+            Passing default to #index_name_exists? is deprecated without replacement.
+          MSG
+        end
         index_name = index_name.to_s
         indexes(table_name).detect { |i| i.name == index_name }
       end

activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb

@@ -133,6 +133,11 @@ module ActiveRecord
 
         # Verifies existence of an index with a given name.
         def index_name_exists?(table_name, index_name, default = nil)
+          unless default.nil?
+            ActiveSupport::Deprecation.warn(<<-MSG.squish)
+              Passing default to #index_name_exists? is deprecated without replacement.
+            MSG
+          end
           table = Utils.extract_schema_qualified_name(table_name.to_s)
           index = Utils.extract_schema_qualified_name(index_name.to_s)
 

activerecord/test/cases/migration/index_test.rb

@@ -31,8 +31,10 @@ module ActiveRecord
         connection.add_index(table_name, [:foo], name: "old_idx")
         connection.rename_index(table_name, "old_idx", "new_idx")
 
-        assert_not connection.index_name_exists?(table_name, "old_idx")
-        assert connection.index_name_exists?(table_name, "new_idx")
+        assert_deprecated do
+          assert_not connection.index_name_exists?(table_name, "old_idx", false)
+          assert connection.index_name_exists?(table_name, "new_idx", true)
+        end
       end
 
       def test_rename_index_too_long