Change inheritance config from skipping to explicit inherit of sections

Author: Envek

README.md

@@ -56,15 +56,16 @@ Inheritance of page objects is supported:
 
 ```ruby
 class FancyIndexPage < IndexPage
-  section :collection, skip: true
-  section :fancy_collection
+  inherit_section :title
+  section         :fancy_collection
+  inherit_section :index_url, if: :readonly_on?
 
   def fancy_collection
     collection.map(&:fancy)
   end
 end
 
-FancyIndexPage.new(Account.find(99)).to_h
+FancyIndexPage.new(Account.find(99)).to_h # => { :title => "…", fancy_collection: […] } 
 ```
 
 ## Development

lib/tram/page.rb

@@ -20,6 +20,17 @@ def section(name, options = {})
       @__sections[n] = section
     end
 
+    def sections
+      @__sections
+    end
+
+    def inherit_section(name, option_overrides={})
+      n = name.to_sym
+      parent_section = superclass.sections[n]
+      options = Tram::Page::Section.dry_initializer.attributes(parent_section)
+      section(name, options.merge(option_overrides))
+    end
+
     def url_helper(name)
       raise "Rails url_helpers module is not defined" unless defined?(Rails)
       delegate name, to: :"Rails.application.routes.url_helpers"
@@ -30,10 +41,6 @@ def url_helper(name)
     def define_section_method(n, section)
       define_method(n) { section.value(self) }
     end
-
-    def inherited(subclass)
-      subclass.instance_variable_set(:@__sections, @__sections.dup)
-    end
   end
 
   def to_h(options = {})

lib/tram/page/section.rb

@@ -1,28 +1,36 @@
 # frozen_string_literal: true
 
 class Tram::Page::Section
-  extend Dry::Initializer
+  extend ::Dry::Initializer
 
   param  :name
-  option :value,  optional: true, as: :getter
-  option :if,     optional: true, as: :positive
-  option :unless, optional: true, as: :negative
+  option :value,  optional: true
+  option :if,     optional: true
+  option :unless, optional: true
 
   # Takes the page instance and extracts a hash for the section
   def call(page)
     show?(page) ? { name => value(page) } : {}
   end
 
   def value(page)
-    getter ? page.instance_exec(&getter) : page.public_send(name)
+    if attributes[:value]
+      page.instance_exec(&attributes[:value])
+    else
+      page.public_send(name)
+    end
   end
 
   private
 
+  def attributes
+    @attributes ||= self.class.dry_initializer.attributes(self)
+  end
+
   def show?(page)
     condition  = true
-    condition &= page.send(positive)  if positive
-    condition &= !page.send(negative) if negative
+    condition &=  page.__send__(attributes[:if])     if attributes[:if]
+    condition &= !page.__send__(attributes[:unless]) if attributes[:unless]
     condition
   end
 end

spec/support/inherited_page.rb

@@ -1,10 +1,15 @@
 # frozen_string_literal: true
 
 class InheritedPage < ExamplePage
-  section :baz, skip: true
+  inherit_section :foo
+  inherit_section :bar, if: :no_bar
   section :bam
 
   def bam
     baz.upcase
   end
+
+  def no_bar
+    !bar
+  end
 end

spec/tram/inherited_page_spec.rb

@@ -6,7 +6,7 @@
   subject { described_class.new("test") }
 
   it "returns data hash with new and without skipped fields" do
-    expect(subject.to_h).to eq(bar: "test", foo: "test", bam: "TEST")
+    expect(subject.to_h).to eq(foo: "test", bam: "TEST")
   end
 
   it "doesn't change behaviour of the parent class" do