1 files changed, 66 insertions, 0 deletions
diff --git a/railties/test/application/dbconsole_test.rb b/railties/test/application/dbconsole_test.rb
new file mode 100644
index 0000000000..7e5e9ea8aa
--- /dev/null
+++ b/railties/test/application/dbconsole_test.rb
@@ -0,0 +1,66 @@
+require "isolation/abstract_unit"
+begin
+  require "pty"
+rescue LoadError
+end
+
+module ApplicationTests
+  class DBConsoleTest < ActiveSupport::TestCase
+    include ActiveSupport::Testing::Isolation
+
+    def setup
+      build_app
+    end
+
+    def teardown
+      teardown_app
+    end
+
+    def test_use_value_defined_in_environment_file_in_database_yml
+      skip "PTY unavailable" unless available_pty?
+      Dir.chdir(app_path) do
+        app_file "config/database.yml", <<-YAML
+          development:
+             database: <%= Rails.application.config.database %>
+             adapter: sqlite3
+             pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
+             timeout: 5000
+        YAML
+
+        app_file "config/environments/development.rb", <<-RUBY
+          Rails.application.configure do
+            config.database = "db/development.sqlite3"
+          end
+        RUBY
+      end
+
+      master, slave = PTY.open
+      spawn_dbconsole(slave)
+      assert_output("sqlite>", master)
+    ensure
+      master.puts ".exit"
+    end
+
+    private
+      def spawn_dbconsole(fd)
+        Process.spawn("#{app_path}/bin/rails dbconsole", in: fd, out: fd, err: fd)
+      end
+
+      def assert_output(expected, io, timeout = 5)
+        timeout = Time.now + timeout
+
+        output = ""
+        until output.include?(expected) || Time.now > timeout
+          if IO.select([io], [], [], 0.1)
+            output << io.read(1)
+          end
+        end
+
+        assert_includes output, expected, "#{expected.inspect} expected, but got:\n\n#{output}"
+      end
+
+      def available_pty?
+        defined?(PTY) && PTY.respond_to?(:open)
+      end
+  end
+end