Extend all test tasks to run against every configured test db (WIP)

bin/rails

@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
 APP_PATH = File.expand_path("../config/application", __dir__)
 require_relative "../config/boot"
+require_relative "../lib/core_ext/test_multiple_adapters.rb"
 require "rails/commands"

config/database.yml.dist

@@ -42,9 +42,24 @@ production:
 #  <<: *default
 #  database: fixinme_dev
 
-# Warning: The database defined as "test" will be erased and
-# re-generated from your development database when you run "rake".
-# Do not set this db to the same as development or production.
+# Warning: Test databases will be erased and re-generated from your development
+# database when you run "rake". Do not set these dbs to the same as development
+# or production.
+#
+# Multiple test databases can be provided. When more than one test db is
+# present, every test task (test, test:models, test:system, etc.) automatically
+# runs against all of them.
+#
+# In additional test databases only "adapter", "database", "host", "port" and
+# "socket" settings are used. All settings default to values specified in
+# "test" - which is required in all test setups.
 #test:
 #  <<: *default
 #  database: fixinme_test
+#
+#test_sqlite3:
+#  adapter: sqlite3
+#  database: db/fixinme_test.sqlite3
+#
+#test_postgresql:
+#  adapter: postgresql

lib/core_ext/test_multiple_adapters.rb

@@ -0,0 +1,42 @@
+require "byebug"
+
+module CoreExt
+  module TestMultipleAdapters
+    def perform(...)
+      #require APP_PATH
+      $LOAD_PATH << Rails::Command.root.join("test").to_s
+      require "test_helper"
+
+      Rails.application.config.database_configuration.each_pair do |name, config|
+        next unless name.start_with?('test_')
+
+        puts config['adapter']
+        ENV['DATABASE_URL'] = dbconfig_to_url(config)
+        byebug
+        super
+      end
+    end
+
+    alias_method :test, :perform
+
+    private
+
+    def dbconfig_to_url(cfg)
+      return cfg['url'] if cfg.has_key?("url")
+
+      config = cfg.transform_values { |v| URI.encode_www_form_component(v) }
+
+      username, password = config.delete('username'), config.delete('password')
+      auth = username ? "#{username}:#{password}" : ''
+      host, port = config.delete('host'), config.delete('port')
+      server = port ? "#{host}:#{port}" : host
+      url = "#{config.delete('adapter')}:"
+      url += "//#{auth}@#{server}" if auth || server
+      url += "/#{config.delete('database')}"
+      url += "?#{config.map { |k,v| "#{k}=#{v}" }.join('&')}" unless config.empty?
+    end
+  end
+end
+
+#require "rails/commands/test/test_command"
+#Rails::Command::TestCommand.prepend CoreExt::TestMultipleAdapters

test/application_system_test_case.rb

@@ -56,4 +56,8 @@ class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
     #   find('a[disabled]').click
     # end
   #end
+
+  # TODO: override #test, creating per-adapter test methods running within
+  # #with_connection?
+  # define shards for test database
 end

test/controllers/users_controller_test.rb

@@ -2,7 +2,7 @@ require "test_helper"
 
 class UsersControllerTest < ActionDispatch::IntegrationTest
   setup do
-    @user = users(:one)
+    @user = users(:admin)
   end
 
   test "should get index" do

test/system/users_test.rb

@@ -6,6 +6,7 @@ class UsersTest < ApplicationSystemTestCase
   end
 
   test 'sign in' do
+    byebug
     visit root_url
     assert find_link(href: new_user_session_path)[:disabled]