Engine: Add auto_close_omitted_tags option

lib/herb/cli.rb

@@ -8,7 +8,8 @@
 class Herb::CLI
   include Herb::Colors
 
-  attr_accessor :json, :silent, :no_interactive, :no_log_file, :no_timing, :local, :escape, :no_escape, :freeze, :debug, :tool, :strict
+  attr_accessor :json, :silent, :no_interactive, :no_log_file, :no_timing, :local, :escape, :no_escape, :freeze, :debug, :tool, :strict,
+                :auto_close_tags
 
   def initialize(args)
     @args = args
@@ -246,6 +247,10 @@ def option_parser
         self.strict = false
       end
 
+      parser.on("--auto-close-tags", "Auto-insert closing tags for elements with omitted closing tags (for compile/render commands)") do
+        self.auto_close_tags = true
+      end
+
       parser.on("--tool TOOL", "Show config for specific tool: linter, formatter (for config command)") do |t|
         self.tool = t.to_sym
       end
@@ -294,6 +299,7 @@ def compile_template
       options[:escape] = no_escape ? false : true
       options[:freeze] = true if freeze
       options[:strict] = strict.nil? || strict
+      options[:auto_close_omitted_tags] = auto_close_tags
 
       if debug
         options[:debug] = true
@@ -309,6 +315,7 @@ def compile_template
           filename: engine.filename,
           bufvar: engine.bufvar,
           strict: options[:strict],
+          auto_close_omitted_tags: options[:auto_close_omitted_tags],
         }
 
         puts result.to_json
@@ -362,6 +369,7 @@ def render_template
       options[:escape] = no_escape ? false : true
       options[:freeze] = true if freeze
       options[:strict] = strict.nil? || strict
+      options[:auto_close_omitted_tags] = auto_close_tags
 
       if debug
         options[:debug] = true
@@ -379,6 +387,7 @@ def render_template
           output: rendered_output,
           filename: engine.filename,
           strict: options[:strict],
+          auto_close_omitted_tags: options[:auto_close_omitted_tags],
         }
 
         puts result.to_json

lib/herb/engine.rb

@@ -17,7 +17,7 @@
 module Herb
   class Engine
     attr_reader :src, :filename, :project_path, :relative_file_path, :bufvar, :debug, :content_for_head,
-                :validation_error_template, :visitors
+                :validation_error_template, :visitors, :auto_close_omitted_tags
 
     ESCAPE_TABLE = {
       "&" => "&",
@@ -52,6 +52,7 @@ def initialize(input, properties = {})
       @validation_error_template = nil
       @validation_mode = properties.fetch(:validation_mode, :raise)
       @strict = properties.fetch(:strict, true)
+      @auto_close_omitted_tags = properties.fetch(:auto_close_omitted_tags, false)
       @visitors = properties.fetch(:visitors, default_visitors)
 
       if @debug && @visitors.empty?

lib/herb/engine/compiler.rb

@@ -13,6 +13,7 @@ def initialize(engine, options = {})
         @attrfunc = options.fetch(:attrfunc, @escape ? "__herb.attr" : "::Herb::Engine.attr")
         @jsfunc = options.fetch(:jsfunc, @escape ? "__herb.js" : "::Herb::Engine.js")
         @cssfunc = options.fetch(:cssfunc, @escape ? "__herb.css" : "::Herb::Engine.css")
+        @auto_close_omitted_tags = options.fetch(:auto_close_omitted_tags, false)
         @tokens = [] #: Array[untyped]
         @element_stack = [] #: Array[String]
         @context_stack = [:html_content]
@@ -146,7 +147,18 @@ def visit_html_close_tag_node(node)
       end
 
       def visit_html_omitted_close_tag_node(node)
-        # no-op
+        return unless @auto_close_omitted_tags
+
+        tag_name = node.tag_name&.value
+
+        if @engine.content_for_head && tag_name&.downcase == "head"
+          escaped_html = @engine.content_for_head.gsub("'", "\\\\'")
+          @tokens << [:expr, "'#{escaped_html}'.html_safe", current_context]
+        end
+
+        add_text("</")
+        add_text(tag_name)
+        add_text(">")
       end
 
       def visit_html_text_node(node)