Merge pull request #161 from emptyflask/emptyflask/nested-undefined

[changelog]

version: unreleased
fixed: "Allow nested settings to default to `Undefined` (fixes #158 via #161) (@emptyflask)"

lib/dry/configurable/dsl.rb

@@ -6,7 +6,7 @@ module Configurable
     #
     # @api private
     class DSL
-      VALID_NAME = /\A[a-z_]\w*\z/i.freeze
+      VALID_NAME = /\A[a-z_]\w*\z/i
 
       attr_reader :compiler
 
@@ -38,7 +38,7 @@ def setting(name, **options, &block) # rubocop:disable Metrics/AbcSize, Metrics/
         node = [:setting, [name.to_sym, options]]
 
         if block
-          ast << [:nested, [node, DSL.new(&block).ast]]
+          ast << [:nested, [node, DSL.new(**@options, &block).ast]]
         else
           ast << node
         end

spec/integration/dry/configurable/defaults_spec.rb

@@ -8,11 +8,15 @@
       setting :foo
       setting :bar, constructor: -> v { v.upcase }
       setting :baz, default: "baz", constructor: -> v { v.upcase }
+      setting :qux do
+        setting :quux
+      end
     end
 
     expect(klass.config.foo).to be(Dry::Configurable::Undefined)
     expect(klass.config.bar).to be(Dry::Configurable::Undefined)
     expect(klass.config.baz).to eq "BAZ"
+    expect(klass.config.qux.quux).to be(Dry::Configurable::Undefined)
 
     klass.configure do |config|
       config.foo = "foo"