1 files changed, 35 insertions, 0 deletions
diff --git a/activerecord/test/cases/unconnected_test.rb b/activerecord/test/cases/unconnected_test.rb
new file mode 100644
index 0000000000..f4d8be5897
--- /dev/null
+++ b/activerecord/test/cases/unconnected_test.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+
+class TestRecord < ActiveRecord::Base
+end
+
+class TestUnconnectedAdapter < ActiveRecord::TestCase
+  self.use_transactional_tests = false
+
+  def setup
+    @underlying = ActiveRecord::Base.connection
+    @specification = ActiveRecord::Base.remove_connection
+  end
+
+  teardown do
+    @underlying = nil
+    ActiveRecord::Base.establish_connection(@specification)
+    load_schema if in_memory_db?
+  end
+
+  def test_connection_no_longer_established
+    assert_raise(ActiveRecord::ConnectionNotEstablished) do
+      TestRecord.find(1)
+    end
+
+    assert_raise(ActiveRecord::ConnectionNotEstablished) do
+      TestRecord.new.save
+    end
+  end
+
+  def test_underlying_adapter_no_longer_active
+    assert !@underlying.active?, "Removed adapter should no longer be active"
+  end
+end