Improve Haml 6 support (#2590)

Gemfile.lock

@@ -1,13 +1,13 @@
 PATH
   remote: middleman-cli
   specs:
-    middleman-cli (4.4.2)
+    middleman-cli (4.4.3)
       thor (>= 0.17.0, < 2.0)
 
 PATH
   remote: middleman-core
   specs:
-    middleman-core (4.4.2)
+    middleman-core (4.4.3)
       activesupport (>= 6.1, < 7.1)
       addressable (~> 2.4)
       backports (~> 3.6)

middleman-core/fixtures/content-for-app/source/content_for_haml.html.haml

@@ -1,4 +1,4 @@
-= content_for :from_template do
-  = "I am the yielded content haml <s>with html tags</s>"
+- content_for :from_template do
+  != "I am the yielded content haml <s>with html tags</s>"
 
 %p I am in the template

middleman-core/lib/middleman-core/renderers/haml.rb

@@ -29,12 +29,18 @@ def initialize(*args, &block)
       def prepare; end
 
       def evaluate(scope, locals, &block)
-        options = {}.merge!(@options).merge!(filename: eval_file, line: line, context: @context || scope)
+        options = {}.merge!(@options).merge!(context: @context || scope)
         if options.include?(:outvar)
           options[:buffer] = options.delete(:outvar)
           options[:save_buffer] = true
         end
-        @engine = ::Haml::Engine.new(data, options)
+        if Object.const_defined?('::Haml::Template') # haml 6+
+          @engine = ::Haml::Template.new(eval_file, line, options) { data }
+        else
+          options[:filename] = eval_file
+          options[:line] = line
+          @engine = ::Haml::Engine.new(data, options)
+        end
         output = @engine.render(scope, locals, &block)
 
         output
@@ -46,21 +52,44 @@ class Haml < ::Middleman::Extension
       def initialize(app, options={}, &block)
         super
 
-        ::Haml::Options.defaults[:context] = nil
-        ::Haml::Options.send :attr_accessor, :context
+        if Object.const_defined?('::Haml::Options') # Haml 5 and older
+          ::Haml::Options.defaults[:context] = nil
+          ::Haml::Options.send :attr_accessor, :context
+        else # Haml 6+
+          ::Haml::Engine.define_options context: nil
+        end
         if defined?(::Haml::TempleEngine)
           ::Haml::TempleEngine.define_options context: nil
         end
 
         # rubocop:disable NestedMethodDefinition
         [::Haml::Filters::Sass, ::Haml::Filters::Scss, ::Haml::Filters::Markdown].each do |f|
           f.class_exec do
-            def self.render_with_options(text, compiler_options)
-              modified_options = options.dup
-              modified_options[:context] = compiler_options[:context]
-
-              text = template_class.new(nil, 1, modified_options) { text }.render
-              super(text, compiler_options)
+            if respond_to?(:template_class) # Haml 5 and older
+              def self.render_with_options(text, compiler_options)
+                modified_options = options.dup
+                modified_options[:context] = compiler_options[:context]
+
+                text = template_class.new(nil, 1, modified_options) { text }.render
+                super(text, compiler_options)
+              end
+            else # Haml 6+
+              def initialize(options = {})
+                super
+                @context = options[:context]
+              end
+
+              def compile_with_tilt(node, name, indent_width: 0)
+                options = { context: @context }
+                source = node.value[:text]
+                result = ::Tilt["t.#{name}"].new(nil, 1, options) { source }.render
+
+                temple = [:multi, [:static, result.gsub(/^/, ' ' * indent_width)]]
+                source.lines.size.times do
+                  temple << [:newline]
+                end
+                temple
+              end
             end
           end
         end

middleman/middleman.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency('middleman-core', Middleman::VERSION)
   s.add_dependency('middleman-cli', Middleman::VERSION)
-  s.add_dependency('haml', ['>= 4.0.5', '< 6.0'])
+  s.add_dependency('haml', ['>= 4.0.5'])
   s.add_dependency('coffee-script', ['~> 2.2'])
   s.add_dependency('kramdown', ['>= 2.3.0'])
 end