Allow builder with argument.

Author: ioquatix

lib/async/service/environment.rb

@@ -24,7 +24,24 @@ def self.for(*facets, **values, &block)
 						end
 					end
 
-					builder.instance_exec(&block) if block_given?
+					# This allows for a convenient syntax, e.g.:
+					#
+					# 	Builder.for do
+					# 		foo 42
+					# 	end
+					#
+					# or:
+					#
+					# 	Builder.for do |builder|
+					# 		builder.foo 42
+					# 	end 
+					if block_given?
+						if block.arity == 0
+							builder.instance_exec(&block)
+						else
+							yield builder
+						end
+					end
 
 					return top
 				end

test/async/service/environment.rb

@@ -28,6 +28,14 @@ def my_method(x, y)
 		expect(environment.to_h).to have_keys(my_key: be == 'value')
 	end
 
+	it 'can use other methods' do
+		environment = subject.build do |builder|
+			builder.dir __dir__
+		end
+		
+		expect(environment.to_h).to have_keys(dir: be == __dir__)
+	end
+	
 	it 'can evaluate methods' do
 		environment = subject.build do
 			include MyEnvironment