Merge pull request #35242 from eileencodes/add-setter-and-deprecation…

…-for-configurations-hashes

Add setter and deprecation for configurations hashes

activerecord/lib/active_record/database_configurations.rb

@@ -102,6 +102,7 @@ def env_with_configs(env = nil)
 
       def build_configs(configs)
         return configs.configurations if configs.is_a?(DatabaseConfigurations)
+        return configs if configs.is_a?(Array)
 
         build_db_config = configs.each_pair.flat_map do |env_name, config|
           walk_configs(env_name.to_s, "primary", config)
@@ -166,21 +167,38 @@ def build_url_config(url, configs)
       end
 
       def method_missing(method, *args, &blk)
-        if Hash.method_defined?(method)
-          ActiveSupport::Deprecation.warn \
-            "Returning a hash from ActiveRecord::Base.configurations is deprecated. Therefore calling `#{method}` on the hash is also deprecated. Please switch to using the `configs_for` method instead to collect and iterate over database configurations."
-        end
-
         case method
         when :each, :first
+          throw_getter_deprecation(method)
           configurations.send(method, *args, &blk)
         when :fetch
+          throw_getter_deprecation(method)
           configs_for(env_name: args.first)
         when :values
+          throw_getter_deprecation(method)
           configurations.map(&:config)
+        when :[]=
+          throw_setter_deprecation(method)
+
+          env_name = args[0]
+          config = args[1]
+
+          remaining_configs = configurations.reject { |db_config| db_config.env_name == env_name }
+          new_config = build_configs(env_name => config)
+          new_configs = remaining_configs + new_config
+
+          ActiveRecord::Base.configurations = new_configs
         else
-          super
+          raise NotImplementedError, "`ActiveRecord::Base.configurations` in Rails 6 now returns an object instead of a hash. The #{method} method is not supported. Please use `configs_for` or consult the documentation for supported methods."
         end
       end
+
+      def throw_setter_deprecation(method)
+        ActiveSupport::Deprecation.warn("Setting `ActiveRecord::Base.configurations` with `#{method}` is deprecated. Use `ActiveRecord::Base.configurations=` directly to set the configurations instead.")
+      end
+
+      def throw_getter_deprecation(method)
+        ActiveSupport::Deprecation.warn("`ActiveRecord::Base.configurations` no longer returns a hash. Methods that act on the hash like `#{method}` are deprecated and will be removed in Rails 6.1. Use the `configs_for` method to collect and iterate over the database configurations.")
+      end
   end
 end

activerecord/test/cases/database_configurations_test.rb

@@ -0,0 +1,117 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+
+class DatabaseConfigurationsTest < ActiveRecord::TestCase
+  unless in_memory_db?
+    def test_empty_returns_true_when_db_configs_are_empty
+      old_config = ActiveRecord::Base.configurations
+      config = {}
+
+      ActiveRecord::Base.configurations = config
+
+      assert_predicate ActiveRecord::Base.configurations, :empty?
+      assert_predicate ActiveRecord::Base.configurations, :blank?
+    ensure
+      ActiveRecord::Base.configurations = old_config
+      ActiveRecord::Base.establish_connection :arunit
+    end
+  end
+
+  def test_configs_for_getter_with_env_name
+    configs = ActiveRecord::Base.configurations.configs_for(env_name: "arunit")
+
+    assert_equal 1, configs.size
+    assert_equal ["arunit"], configs.map(&:env_name)
+  end
+
+  def test_configs_for_getter_with_env_and_spec_name
+    config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", spec_name: "primary")
+
+    assert_equal "arunit", config.env_name
+    assert_equal "primary", config.spec_name
+  end
+
+  def test_default_hash_returns_config_hash_from_default_env
+    original_rails_env = ENV["RAILS_ENV"]
+    ENV["RAILS_ENV"] = "arunit"
+
+    assert_equal ActiveRecord::Base.configurations.configs_for(env_name: "arunit", spec_name: "primary").config, ActiveRecord::Base.configurations.default_hash
+  ensure
+    ENV["RAILS_ENV"] = original_rails_env
+  end
+
+  def test_find_db_config_returns_a_db_config_object_for_the_given_env
+    config = ActiveRecord::Base.configurations.find_db_config("arunit2")
+
+    assert_equal "arunit2", config.env_name
+    assert_equal "primary", config.spec_name
+  end
+
+  def test_to_h_turns_db_config_object_back_into_a_hash
+    configs = ActiveRecord::Base.configurations
+    assert_equal "ActiveRecord::DatabaseConfigurations", configs.class.name
+    assert_equal "Hash", configs.to_h.class.name
+    assert_equal ["arunit", "arunit2", "arunit_without_prepared_statements"], ActiveRecord::Base.configurations.to_h.keys.sort
+  end
+end
+
+class LegacyDatabaseConfigurationsTest < ActiveRecord::TestCase
+  unless in_memory_db?
+    def test_setting_configurations_hash
+      old_config = ActiveRecord::Base.configurations
+      config = { "adapter" => "sqlite3" }
+
+      assert_deprecated do
+        ActiveRecord::Base.configurations["readonly"] = config
+      end
+
+      assert_equal ["arunit", "arunit2", "arunit_without_prepared_statements", "readonly"], ActiveRecord::Base.configurations.configs_for.map(&:env_name).sort
+    ensure
+      ActiveRecord::Base.configurations = old_config
+      ActiveRecord::Base.establish_connection :arunit
+    end
+  end
+
+  def test_can_turn_configurations_into_a_hash
+    assert ActiveRecord::Base.configurations.to_h.is_a?(Hash), "expected to be a hash but was not."
+    assert_equal ["arunit", "arunit2", "arunit_without_prepared_statements"].sort, ActiveRecord::Base.configurations.to_h.keys.sort
+  end
+
+  def test_each_is_deprecated
+    assert_deprecated do
+      ActiveRecord::Base.configurations.each do |db_config|
+        assert_equal "primary", db_config.spec_name
+      end
+    end
+  end
+
+  def test_first_is_deprecated
+    assert_deprecated do
+      db_config = ActiveRecord::Base.configurations.first
+      assert_equal "arunit", db_config.env_name
+      assert_equal "primary", db_config.spec_name
+    end
+  end
+
+  def test_fetch_is_deprecated
+    assert_deprecated do
+      db_config = ActiveRecord::Base.configurations.fetch("arunit").first
+      assert_equal "arunit", db_config.env_name
+      assert_equal "primary", db_config.spec_name
+    end
+  end
+
+  def test_values_are_deprecated
+    config_hashes = ActiveRecord::Base.configurations.configurations.map(&:config)
+    assert_deprecated do
+      assert_equal config_hashes, ActiveRecord::Base.configurations.values
+    end
+  end
+
+  def test_unsupported_method_raises
+    assert_raises NotImplementedError do
+      ActiveRecord::Base.configurations.select { |a| a == "foo" }
+    end
+  end
+end