add global_filter

add a global filter using a proc
only add one proc and not an array
add tests to make sure the global_filter is applied after native filters

lib/liquid/context.rb

@@ -13,7 +13,7 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     attr_reader :scopes, :errors, :registers, :environments, :resource_limits
-    attr_accessor :exception_handler, :template_name, :partial
+    attr_accessor :exception_handler, :template_name, :partial, :global_filter
 
     def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil)
       @environments     = [environments].flatten
@@ -32,6 +32,7 @@ module Liquid
 
       @interrupts = []
       @filters = []
+      @global_filter = nil
     end
 
     def warnings
@@ -52,6 +53,10 @@ module Liquid
       @strainer = nil
     end
 
+    def apply_global_filter(obj)
+      global_filter.nil? ? obj : global_filter.call(obj)
+    end
+
     # are there any not handled interrupts?
     def interrupt?
       !@interrupts.empty?

lib/liquid/template.rb

@@ -179,20 +179,15 @@ module Liquid
       when Hash
         options = args.pop
 
-        if options[:registers].is_a?(Hash)
-          registers.merge!(options[:registers])
-        end
+        registers.merge!(options[:registers]) if options[:registers].is_a?(Hash)
 
-        if options[:filters]
-          context.add_filters(options[:filters])
-        end
+        context.add_filters(options[:filters]) if options[:filters]
 
-        if options[:exception_handler]
-          context.exception_handler = options[:exception_handler]
-        end
-      when Module
-        context.add_filters(args.pop)
-      when Array
+        context.global_filter = options[:global_filter] if options[:global_filter]
+
+        context.exception_handler = options[:exception_handler] if options[:exception_handler]
+
+      when Module, Array
         context.add_filters(args.pop)
       end
 

lib/liquid/variable.rb

@@ -73,10 +73,16 @@ module Liquid
     end
 
     def render(context)
-      @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
+      obj = @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
         filter_args = evaluate_filter_expressions(context, filter_args, filter_kwargs)
         context.invoke(filter_name, output, *filter_args)
-      end.tap{ |obj| taint_check(context, obj) }
+      end
+
+      obj = context.apply_global_filter(obj)
+
+      taint_check(context, obj)
+
+      obj
     end
 
     private

test/integration/template_test.rb

@@ -211,4 +211,18 @@ class TemplateTest < Minitest::Test
     end
     assert exception.is_a?(Liquid::ZeroDivisionError)
   end
+
+  def test_global_filter_option_on_render
+    global_filter_proc = ->(output) { "#{output} filtered" }
+    rendered_template = Template.parse("{{name}}").render({ "name" => "bob" }, global_filter: global_filter_proc)
+
+    assert_equal 'bob filtered', rendered_template
+  end
+
+  def test_global_filter_option_when_native_filters_exist
+    global_filter_proc = ->(output) { "#{output} filtered" }
+    rendered_template = Template.parse("{{name | upcase}}").render({ "name" => "bob" }, global_filter: global_filter_proc)
+
+    assert_equal 'BOB filtered', rendered_template
+  end
 end

test/unit/context_unit_test.rb

@@ -466,4 +466,18 @@ class ContextUnitTest < Minitest::Test
     assert contx
     assert_nil contx['poutine']
   end
+
+  def test_apply_global_filter
+    global_filter_proc = ->(output) { "#{output} filtered" }
+
+    context = Context.new
+    context.global_filter = global_filter_proc
+
+    assert_equal 'hi filtered', context.apply_global_filter('hi')
+  end
+
+  def test_apply_global_filter_when_no_global_filter_exist
+    context = Context.new
+    assert_equal 'hi', context.apply_global_filter('hi')
+  end
 end # ContextTest