From 9d9d65cd9890fa584dbcffc25a2adc8d538d6db9 Mon Sep 17 00:00:00 2001
From: nepalez <andrew.kozin@gmail.com>
Date: Mon, 15 Apr 2019 23:33:03 +0300
Subject: [PATCH] Fix validation of underscored names

---
 lib/dry/initializer/dispatchers/build_nested_type.rb | 7 ++++---
 spec/type_constraint_spec.rb                         | 4 ++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/dry/initializer/dispatchers/build_nested_type.rb b/lib/dry/initializer/dispatchers/build_nested_type.rb
index f1f6609..f05a5c7 100644
--- a/lib/dry/initializer/dispatchers/build_nested_type.rb
+++ b/lib/dry/initializer/dispatchers/build_nested_type.rb
@@ -13,7 +13,7 @@ module Dry::Initializer::Dispatchers::BuildNestedType
   # rubocop: disable Metrics/ParameterLists
   def call(parent:, source:, target:, type: nil, block: nil, **options)
     check_certainty!(source, type, block)
-    check_name!(target)
+    check_name!(target, block)
     type ||= build_nested_type(parent, target, block)
     { parent: parent, source: source, target: target, type: type, **options }
   end
@@ -22,8 +22,8 @@ def call(parent:, source:, target:, type: nil, block: nil, **options)
   private
 
   def check_certainty!(source, type, block)
-    return unless type
     return unless block
+    return unless type
 
     raise ArgumentError, <<~MESSAGE
       You should define coercer of values of argument '#{source}'
@@ -31,7 +31,8 @@ def check_certainty!(source, type, block)
     MESSAGE
   end
 
-  def check_name!(name)
+  def check_name!(name, block)
+    return unless block
     return unless name[/^_|__|_$/]
 
     raise ArgumentError, <<~MESSAGE
diff --git a/spec/type_constraint_spec.rb b/spec/type_constraint_spec.rb
index 8a0085a..86f4364 100644
--- a/spec/type_constraint_spec.rb
+++ b/spec/type_constraint_spec.rb
@@ -5,14 +5,14 @@
     before do
       class Test::Foo
         extend Dry::Initializer
-        param :foo, proc(&:to_s), optional: true
+        param :__foo__, proc(&:to_s), optional: true
       end
     end
 
     subject { Test::Foo.new :foo }
 
     it "coerces a value" do
-      expect(subject.foo).to eq "foo"
+      expect(subject.__foo__).to eq "foo"
     end
   end