skip migration check if adapter doesn't support it

2 files changed, 58 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb
index b6b02322d7..d0bc4c0af9 100644
--- a/activerecord/lib/active_record/migration.rb
+++ b/activerecord/lib/active_record/migration.rb
@@ -366,16 +366,19 @@ module ActiveRecord
     # This class is used to verify that all migrations have been run before
     # loading a web page if config.active_record.migration_error is set to :page_load
     class CheckPending
-      def initialize(app)
+      def initialize(app, connection = Base.connection)
         @app = app
+        @connection = connection
         @last_check = 0
       end
 
       def call(env)
-        mtime = ActiveRecord::Migrator.last_migration.mtime.to_i
-        if @last_check < mtime
-          ActiveRecord::Migration.check_pending!
-          @last_check = mtime
+        if @connection.supports_migrations?
+          mtime = ActiveRecord::Migrator.last_migration.mtime.to_i
+          if @last_check < mtime
+            ActiveRecord::Migration.check_pending!(@connection)
+            @last_check = mtime
+          end
         end
         @app.call(env)
       end
diff --git a/activerecord/test/cases/migration/pending_migrations_test.rb b/activerecord/test/cases/migration/pending_migrations_test.rb
new file mode 100644
index 0000000000..eff000e1a4
--- /dev/null
+++ b/activerecord/test/cases/migration/pending_migrations_test.rb
@@ -0,0 +1,50 @@
+require 'cases/helper'
+require "minitest/mock"
+
+module ActiveRecord
+  class Migration
+    class PendingMigrationsTest < ActiveRecord::TestCase
+      def setup
+        super
+        @connection = MiniTest::Mock.new
+        @app = MiniTest::Mock.new
+        @pending = CheckPending.new(@app, @connection)
+        @pending.instance_variable_set :@last_check, -1 # Force checking
+      end
+
+      def teardown
+        super
+        assert @connection.verify
+        assert @app.verify
+      end
+
+      def test_errors_if_pending
+        @connection.expect :supports_migrations?, true
+
+        ActiveRecord::Migrator.stub :needs_migration?, true do
+          assert_raise ActiveRecord::PendingMigrationError do
+            @pending.call(nil)
+          end
+        end
+      end
+
+      def test_checks_if_supported
+        @connection.expect :supports_migrations?, true
+        @app.expect :call, nil, [:foo]
+
+        ActiveRecord::Migrator.stub :needs_migration?, false do
+          @pending.call(:foo)
+        end
+      end
+
+      def test_doesnt_check_if_unsupported
+        @connection.expect :supports_migrations?, false
+        @app.expect :call, nil, [:foo]
+
+        ActiveRecord::Migrator.stub :needs_migration?, true do
+          @pending.call(:foo)
+        end
+      end
+    end
+  end
+end