The `default` arg of `index_name_exists?` makes to optional

The `default` arg of `index_name_exists?` is only used the adapter does
not implemented `indexes`. But currently all adapters implemented
`indexes` (See #26688). Therefore the `default` arg is never used.

3 files changed, 5 insertions, 9 deletions

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 e0528c1df6..54c4c62636 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -773,11 +773,7 @@ module ActiveRecord
       end
 
       # Verifies the existence of an index with a given name.
-      #
-      # The default argument is returned if the underlying implementation does not define the indexes method,
-      # as there's no way to determine the correct answer in that case.
-      def index_name_exists?(table_name, index_name, default)
-        return default unless respond_to?(:indexes)
+      def index_name_exists?(table_name, index_name, default = nil)
         index_name = index_name.to_s
         indexes(table_name).detect { |i| i.name == index_name }
       end
@@ -1149,7 +1145,7 @@ module ActiveRecord
 
         validate_index_length!(table_name, index_name, options.fetch(:internal, false))
 
-        if data_source_exists?(table_name) && index_name_exists?(table_name, index_name, false)
+        if data_source_exists?(table_name) && index_name_exists?(table_name, index_name)
           raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' already exists"
         end
         index_columns = quoted_columns_for_index(column_names, options).join(", ")
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index a4b1723fc7..f9dffbe87b 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -132,7 +132,7 @@ module ActiveRecord
         end
 
         # Verifies existence of an index with a given name.
-        def index_name_exists?(table_name, index_name, default)
+        def index_name_exists?(table_name, index_name, default = nil)
           table = Utils.extract_schema_qualified_name(table_name.to_s)
           index = Utils.extract_schema_qualified_name(index_name.to_s)
 
diff --git a/activerecord/lib/active_record/migration/compatibility.rb b/activerecord/lib/active_record/migration/compatibility.rb
index ffb54f5137..85032ce470 100644
--- a/activerecord/lib/active_record/migration/compatibility.rb
+++ b/activerecord/lib/active_record/migration/compatibility.rb
@@ -145,13 +145,13 @@ module ActiveRecord
           def index_name_for_remove(table_name, options = {})
             index_name = index_name(table_name, options)
 
-            unless index_name_exists?(table_name, index_name, true)
+            unless index_name_exists?(table_name, index_name)
               if options.is_a?(Hash) && options.has_key?(:name)
                 options_without_column = options.dup
                 options_without_column.delete :column
                 index_name_without_column = index_name(table_name, options_without_column)
 
-                return index_name_without_column if index_name_exists?(table_name, index_name_without_column, false)
+                return index_name_without_column if index_name_exists?(table_name, index_name_without_column)
               end
 
               raise ArgumentError, "Index name '#{index_name}' on table '#{table_name}' does not exist"