Revert "Dump indexes in `create_table` instead of `add_index`"

This reverts commit 99801c6a7b69eb4b006a55de17ada78f3a0fa4c1.

Ultimately it doesn't matter whether `add_index` or `t.index` are used
in the schema dumper in any meaningful way. There are gems out there
which hook into the old behavior for things like indexing materialized
views. Since the reverted commit doesn't seem to add much benefit,
there's no reason for us to break these gems.

3 files changed, 16 insertions, 21 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 4ca33491aa..0832652d32 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1004,13 +1004,6 @@
 
     *Alex Coomans*
 
-*   Dump indexes in `create_table` instead of `add_index`.
-
-    If the adapter supports indexes in `create_table`, generated SQL is
-    slightly more efficient.
-
-    *Ryuta Kamizono*
-
 *   Correctly dump `:options` on `create_table` for MySQL.
 
     *Ryuta Kamizono*
diff --git a/activerecord/lib/active_record/schema_dumper.rb b/activerecord/lib/active_record/schema_dumper.rb
index 65005bd44b..f115c7542b 100644
--- a/activerecord/lib/active_record/schema_dumper.rb
+++ b/activerecord/lib/active_record/schema_dumper.rb
@@ -178,11 +178,11 @@ HEADER
             tbl.puts
           end
 
-          indexes(table, tbl)
-
           tbl.puts "  end"
           tbl.puts
 
+          indexes(table, tbl)
+
           tbl.rewind
           stream.print tbl.read
         rescue => e
@@ -198,7 +198,8 @@ HEADER
         if (indexes = @connection.indexes(table)).any?
           add_index_statements = indexes.map do |index|
             statement_parts = [
-              "t.index #{index.columns.inspect}",
+              "add_index #{remove_prefix_and_suffix(index.table).inspect}",
+              index.columns.inspect,
               "name: #{index.name.inspect}",
             ]
             statement_parts << 'unique: true' if index.unique
@@ -212,10 +213,11 @@ HEADER
             statement_parts << "using: #{index.using.inspect}" if index.using
             statement_parts << "type: #{index.type.inspect}" if index.type
 
-            "    #{statement_parts.join(', ')}"
+            "  #{statement_parts.join(', ')}"
           end
 
           stream.puts add_index_statements.sort.join("\n")
+          stream.puts
         end
       end
 
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 25f4a69ad1..8def74e75b 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -171,24 +171,24 @@ class SchemaDumperTest < ActiveRecord::TestCase
   end
 
   def test_schema_dumps_index_columns_in_right_order
-    index_definition = standard_dump.split(/\n/).grep(/t\.index.*company_index/).first.strip
+    index_definition = standard_dump.split(/\n/).grep(/add_index.*companies/).first.strip
     if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
-      assert_equal 't.index ["firm_id", "type", "rating"], name: "company_index", using: :btree', index_definition
+      assert_equal 'add_index "companies", ["firm_id", "type", "rating"], name: "company_index", using: :btree', index_definition
     else
-      assert_equal 't.index ["firm_id", "type", "rating"], name: "company_index"', index_definition
+      assert_equal 'add_index "companies", ["firm_id", "type", "rating"], name: "company_index"', index_definition
     end
   end
 
   def test_schema_dumps_partial_indices
-    index_definition = standard_dump.split(/\n/).grep(/t\.index.*company_partial_index/).first.strip
+    index_definition = standard_dump.split(/\n/).grep(/add_index.*company_partial_index/).first.strip
     if current_adapter?(:PostgreSQLAdapter)
-      assert_equal 't.index ["firm_id", "type"], name: "company_partial_index", where: "(rating > 10)", using: :btree', index_definition
+      assert_equal 'add_index "companies", ["firm_id", "type"], name: "company_partial_index", where: "(rating > 10)", using: :btree', index_definition
     elsif current_adapter?(:Mysql2Adapter)
-      assert_equal 't.index ["firm_id", "type"], name: "company_partial_index", using: :btree', index_definition
+      assert_equal 'add_index "companies", ["firm_id", "type"], name: "company_partial_index", using: :btree', index_definition
     elsif current_adapter?(:SQLite3Adapter) && ActiveRecord::Base.connection.supports_partial_index?
-      assert_equal 't.index ["firm_id", "type"], name: "company_partial_index", where: "rating > 10"', index_definition
+      assert_equal 'add_index "companies", ["firm_id", "type"], name: "company_partial_index", where: "rating > 10"', index_definition
     else
-      assert_equal 't.index ["firm_id", "type"], name: "company_partial_index"', index_definition
+      assert_equal 'add_index "companies", ["firm_id", "type"], name: "company_partial_index"', index_definition
     end
   end
 
@@ -235,8 +235,8 @@ class SchemaDumperTest < ActiveRecord::TestCase
 
     def test_schema_dumps_index_type
       output = standard_dump
-      assert_match %r{t\.index \["awesome"\], name: "index_key_tests_on_awesome", type: :fulltext}, output
-      assert_match %r{t\.index \["pizza"\], name: "index_key_tests_on_pizza", using: :btree}, output
+      assert_match %r{add_index "key_tests", \["awesome"\], name: "index_key_tests_on_awesome", type: :fulltext}, output
+      assert_match %r{add_index "key_tests", \["pizza"\], name: "index_key_tests_on_pizza", using: :btree}, output
     end
   end