WIP - Implement indentation whitespace control

lib/liquid.rb

@@ -26,7 +26,9 @@ module Liquid
   ArgumentSeparator           = ','
   FilterArgumentSeparator     = ':'
   VariableAttributeSeparator  = '.'
-  WhitespaceControl           = '-'
+  WhitespaceControl           = '(?:[-~])'
+  WhitespaceTrim              = '-'
+  WhitespaceTrimIndent        = '~'
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
   TagName                     = /#|\w+/

lib/liquid/block_body.rb

@@ -164,6 +164,7 @@ module Liquid
             token.lstrip!
           end
           parse_context.trim_whitespace = false
+          parse_context.strip_trailing = false
           @nodelist << token
           @blank &&= token.match?(WhitespaceOrNothing)
         end
@@ -174,7 +175,8 @@ module Liquid
     end
 
     def whitespace_handler(token, parse_context)
-      if token[2] == WhitespaceControl
+      parse_context.indentation = nil
+      if token[2] == WhitespaceTrim
         previous_token = @nodelist.last
         if previous_token.is_a?(String)
           first_byte = previous_token.getbyte(0)
@@ -183,8 +185,15 @@ module Liquid
             previous_token << first_byte
           end
         end
+      elsif token[2] == WhitespaceTrimIndent
+        previous_token = @nodelist.last
+        if previous_token.is_a?(String)
+          start_of_line = previous_token.rindex("\n") || 0
+          parse_context.indentation = previous_token[start_of_line + 1..]
+        end
       end
-      parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
+      parse_context.trim_whitespace = (token[-3] == WhitespaceTrim)
+      parse_context.strip_trailing = (token[-3] == WhitespaceTrimIndent)
     end
 
     def blank?
@@ -248,7 +257,7 @@ module Liquid
     def create_variable(token, parse_context)
       if token.end_with?("}}")
         i = 2
-        i = 3 if token[i] == "-"
+        i = 3 if token[i] == "-" or token[i] == "~"
         parse_end = token.length - 3
         parse_end -= 1 if token[parse_end] == "-"
         markup_end = parse_end - i + 1

lib/liquid/parse_context.rb

@@ -2,7 +2,7 @@
 
 module Liquid
   class ParseContext
-    attr_accessor :locale, :line_number, :trim_whitespace, :depth
+    attr_accessor :locale, :line_number, :trim_whitespace, :depth, :indentation, :strip_trailing
     attr_reader :partial, :warnings, :error_mode, :environment
 
     def initialize(options = Const::EMPTY_HASH)

lib/liquid/tags/comment.rb

@@ -63,10 +63,11 @@ module Liquid
             comment_tag_depth -= 1
           end
 
-          if comment_tag_depth.zero?
-            parse_context.trim_whitespace = (token[-3] == WhitespaceControl) unless tokenizer.for_liquid_tag
-            return false
-          end
+          next unless comment_tag_depth.zero?
+
+          parse_context.trim_whitespace = (token[-3] == WhitespaceTrim) unless tokenizer.for_liquid_tag
+          parse_context.strip_trailing = (token[-3] == WhitespaceTrimIndent) unless tokenizer.for_liquid_tag
+          return false
         end
 
         raise_tag_never_closed(block_name)

lib/liquid/tags/include.rb

@@ -37,6 +37,7 @@ module Liquid
         @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
         @template_name_expr = parse_expression(template_name)
         @attributes         = {}
+        @indentation        = options.indentation
 
         markup.scan(TagAttributes) do |key, value|
           @attributes[key] = parse_expression(value)
@@ -80,15 +81,25 @@ module Liquid
             context[key] = context.evaluate(value)
           end
 
+          partial_output = +''
           if variable.is_a?(Array)
             variable.each do |var|
               context[context_variable_name] = var
-              partial.render_to_output_buffer(context, output)
+              partial.render_to_output_buffer(context, partial_output)
             end
           else
             context[context_variable_name] = variable
-            partial.render_to_output_buffer(context, output)
+            partial.render_to_output_buffer(context, partial_output)
           end
+
+          if @indentation
+            partial_output = partial_output.lines.map.with_index do |line, i|
+              next line if i == 0
+              @indentation + line
+            end.join
+          end
+
+          output << partial_output
         end
       ensure
         context.template_name = old_template_name

lib/liquid/tags/raw.rb

@@ -25,7 +25,8 @@ module Liquid
       @body = +''
       while (token = tokens.shift)
         if token =~ BlockBody::FullTokenPossiblyInvalid && block_delimiter == Regexp.last_match(2)
-          parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
+          parse_context.trim_whitespace = (token[-3] == WhitespaceTrim)
+          parse_context.strip_trailing = (token[-3] == WhitespaceTrimIndent)
           @body << Regexp.last_match(1) if Regexp.last_match(1) != ""
           return
         end

lib/liquid/tags/render.rb

@@ -46,6 +46,8 @@ module Liquid
       @variable_name_expr = variable_name ? parse_expression(variable_name) : nil
       @template_name_expr = parse_expression(template_name)
       @is_for_loop = (with_or_for == FOR)
+      @indentation = options.indentation
+      @strip_trailing = options.strip_trailing
 
       @attributes = {}
       markup.scan(TagAttributes) do |key, value|
@@ -84,7 +86,18 @@ module Liquid
           inner_context[key] = context.evaluate(value)
         end
         inner_context[context_variable_name] = var unless var.nil?
-        partial.render_to_output_buffer(inner_context, output)
+        partial_output = +''
+        partial.render_to_output_buffer(inner_context, partial_output)
+        if @indentation
+          partial_output = partial_output.lines.map.with_index do |line, i|
+            next line if i == 0
+            @indentation + line
+          end.join
+        end
+        if @strip_trailing
+          partial_output.rstrip!
+        end
+        output << partial_output
         forloop&.send(:increment!)
       }
 

lib/liquid/variable.rb

@@ -29,6 +29,8 @@ module Liquid
       @name          = nil
       @parse_context = parse_context
       @line_number   = parse_context.line_number
+      @indentation   = parse_context.indentation
+      @strip_trailing = parse_context.strip_trailing
 
       strict_parse_with_error_mode_fallback(markup)
     end
@@ -95,21 +97,29 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       obj = render(context)
-      render_obj_to_output(obj, output)
-      output
-    end
 
-    def render_obj_to_output(obj, output)
-      case obj
-      when NilClass
-        # Do nothing
-      when Array
-        obj.each do |o|
-          render_obj_to_output(o, output)
-        end
-      when
-        output << obj.to_s
+      obj_output = ''
+      if obj.is_a?(Array)
+        obj_output = obj.join
+      elsif obj.nil?
+      else
+        obj_output = obj.to_s
       end
+
+      if @indentation
+        obj_output = obj_output.lines.map.with_index do |line, i|
+          next line if i == 0
+          @indentation + line
+        end.join
+      end
+
+      if @strip_trailing
+        obj_output.rstrip!
+      end
+
+      output << obj_output
+
+      output
     end
 
     def disabled?(_context)

test/integration/trim_mode_test.rb

@@ -555,4 +555,139 @@ class TrimModeTest < Minitest::Test
   def test_trim_blank
     assert_template_result('foobar', 'foo {{-}} bar')
   end
+
+  def test_trim_indent_variable
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{~ 'Hello\nWorld' ~}}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_trim_indent_variable_trims_trailing_whitespace
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {{~ 'Hello\nWorld\n' ~}}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+
+  def test_trim_indent_tags
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%~ echo 'Hello\nWorld' ~%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text)
+  end
+
+  def test_trim_indent_include
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%~ include "snippet" ~%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text, partials: {"snippet" => "Hello\nWorld"})
+  end
+
+  def test_trim_indent_render
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%~ render "snippet" ~%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text, partials: {"snippet" => "Hello\nWorld"})
+  end
+
+  def test_trim_indent_render_trim_trailing_whitespace
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%~ render "snippet" ~%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text, partials: {"snippet" => "Hello\nWorld\n"})
+  end
+
+  def test_trim_indent_nested_render
+    text = <<-END_TEMPLATE
+      <div>
+        <p>
+          {%~ render "snippet" ~%}
+        </p>
+      </div>
+    END_TEMPLATE
+    expected = <<-END_EXPECTED
+      <div>
+        <p>
+          Hello
+              inside
+          World
+        </p>
+      </div>
+    END_EXPECTED
+    assert_template_result(expected, text, partials: {"snippet" => "Hello\n    {%~ render \"snippet2\" ~%}\nWorld", "snippet2" => "inside"})
+  end
 end # TrimModeTest

test/integration/variable_test.rb

@@ -130,10 +130,6 @@ class VariableTest < Minitest::Test
     assert_template_result('bar', '{{ foo }}', { 'foo' => :bar })
   end
 
-  def test_nested_array
-    assert_template_result('', '{{ foo }}', { 'foo' => [[nil]] })
-  end
-
   def test_dynamic_find_var
     assert_template_result('bar', '{{ [key] }}', { 'key' => 'foo', 'foo' => 'bar' })
   end