1 files changed, 51 insertions, 0 deletions
diff --git a/activerecord/test/cases/migration/compatibility_test.rb b/activerecord/test/cases/migration/compatibility_test.rb
index e1311c0f21..1ae15eb439 100644
--- a/activerecord/test/cases/migration/compatibility_test.rb
+++ b/activerecord/test/cases/migration/compatibility_test.rb
@@ -199,6 +199,57 @@ class LegacyPrimaryKeyTest < ActiveRecord::TestCase
     assert_match %r{create_table "legacy_primary_keys", id: :integer, default: nil}, schema
   end
 
+  if current_adapter?(:Mysql2Adapter, :PostgreSQLAdapter)
+    def test_legacy_primary_key_in_create_table_should_be_integer
+      @migration = Class.new(ActiveRecord::Migration[5.0]) {
+        def change
+          create_table :legacy_primary_keys, id: false do |t|
+            t.primary_key :id
+          end
+        end
+      }.new
+
+      @migration.migrate(:up)
+
+      schema = dump_table_schema "legacy_primary_keys"
+      assert_match %r{create_table "legacy_primary_keys", id: :(?:integer|serial), (?!default: nil)}, schema
+    end
+
+    def test_legacy_primary_key_in_change_table_should_be_integer
+      @migration = Class.new(ActiveRecord::Migration[5.0]) {
+        def change
+          create_table :legacy_primary_keys, id: false do |t|
+            t.integer :dummy
+          end
+          change_table :legacy_primary_keys do |t|
+            t.primary_key :id
+          end
+        end
+      }.new
+
+      @migration.migrate(:up)
+
+      schema = dump_table_schema "legacy_primary_keys"
+      assert_match %r{create_table "legacy_primary_keys", id: :(?:integer|serial), (?!default: nil)}, schema
+    end
+
+    def test_add_column_with_legacy_primary_key_should_be_integer
+      @migration = Class.new(ActiveRecord::Migration[5.0]) {
+        def change
+          create_table :legacy_primary_keys, id: false do |t|
+            t.integer :dummy
+          end
+          add_column :legacy_primary_keys, :id, :primary_key
+        end
+      }.new
+
+      @migration.migrate(:up)
+
+      schema = dump_table_schema "legacy_primary_keys"
+      assert_match %r{create_table "legacy_primary_keys", id: :(?:integer|serial), (?!default: nil)}, schema
+    end
+  end
+
   def test_legacy_join_table_foreign_keys_should_be_integer
     @migration = Class.new(ActiveRecord::Migration[5.0]) {
       def change