From 2190b4437fbfbed0a52de96340c20f38507a7dac Mon Sep 17 00:00:00 2001
From: Miguel <miguel.torres@hey.com>
Date: Mon, 1 Sep 2025 13:55:52 +0200
Subject: [PATCH 1/3] Update Sorbet and start fixing sorbet errors

---
 lib/herb/position.rb | 7 +++++--
 lib/herb/range.rb    | 7 +++++--
 sorbet/config        | 5 +----
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/lib/herb/position.rb b/lib/herb/position.rb
index f7131d151..1213b0355 100644
--- a/lib/herb/position.rb
+++ b/lib/herb/position.rb
@@ -2,9 +2,12 @@
 # typed: true
 
 module Herb
+  #: type serialized_position = { line: Integer, column: Integer }
   class Position
-    attr_reader :line #: Integer
-    attr_reader :column #: Integer
+    #: Integer
+    attr_reader :line
+    #: Integer
+    attr_reader :column
 
     #: (Integer, Integer) -> void
     def initialize(line, column)
diff --git a/lib/herb/range.rb b/lib/herb/range.rb
index 7adb16c10..edd15a8e9 100644
--- a/lib/herb/range.rb
+++ b/lib/herb/range.rb
@@ -2,9 +2,12 @@
 # typed: true
 
 module Herb
+  #: type serialized_range = [Integer, Integer]
   class Range
-    attr_reader :from #: Integer
-    attr_reader :to #: Integer
+    #: Integer
+    attr_reader :from
+    #: Integer
+    attr_reader :to
 
     #: (Integer, Integer) -> void
     def initialize(from, to)
diff --git a/sorbet/config b/sorbet/config
index e76047cc3..a215ea13d 100644
--- a/sorbet/config
+++ b/sorbet/config
@@ -1,6 +1,3 @@
---dir
-lib/
 --ignore=/tmp/
 --ignore=/vendor/bundle
---enable-experimental-rbs-signatures
---enable-experimental-rbs-assertions
+--enable-experimental-rbs-comments

From ca0eb72e66443c775ab30f403c71e5db0cf0fe0a Mon Sep 17 00:00:00 2001
From: Miguel <miguel.torres@hey.com>
Date: Mon, 22 Sep 2025 15:57:31 +0200
Subject: [PATCH 2/3] Update dynamic values

---
 .github/workflows/build.yml         |  4 ++--
 lib/herb/ast/helpers.rb             |  6 +++---
 lib/herb/ast/node.rb                | 20 ++++++++++++++------
 lib/herb/engine.rb                  |  1 +
 lib/herb/engine/debug_visitor.rb    |  4 ++--
 lib/herb/lex_result.rb              |  4 +++-
 lib/herb/location.rb                | 16 +++++++++++-----
 lib/herb/parse_result.rb            |  1 +
 lib/herb/result.rb                  |  9 ++++++---
 lib/herb/token.rb                   |  8 +++++++-
 lib/herb/warnings.rb                | 14 +++++++++++---
 sig/herb/ast/helpers.rbs            |  2 +-
 sig/herb/token.rbs                  |  4 ++--
 sorbet/config                       |  2 ++
 templates/lib/herb/ast/nodes.rb.erb | 12 ++++++++++--
 templates/lib/herb/errors.rb.erb    | 18 +++++++++++++++---
 templates/lib/herb/visitor.rb.erb   |  4 ++--
 17 files changed, 93 insertions(+), 36 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 307ffd462..2ededbbef 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -59,8 +59,8 @@ jobs:
       - name: RBS Inline
         run: bundle exec rake rbs_inline
 
-      # - name: Sorbet
-      #   run: bundle exec srb tc
+      - name: Sorbet
+        run: bundle exec srb tc
 
       - name: clang-tidy version
         run: clang-tidy-21 --version
diff --git a/lib/herb/ast/helpers.rb b/lib/herb/ast/helpers.rb
index dcd282e83..874cae3b5 100644
--- a/lib/herb/ast/helpers.rb
+++ b/lib/herb/ast/helpers.rb
@@ -4,12 +4,12 @@
 module Herb
   module AST
     module Helpers
-      #: (Herb::AST::Node) -> bool
+      #: (Herb::AST::Node?) -> bool
       def erb_outputs?(node)
         return false unless node.is_a?(Herb::AST::ERBContentNode)
 
-        opening = node.tag_opening&.value
-        opening&.include?("=") && !opening&.start_with?("<%#")
+        opening = node.tag_opening&.value || ""
+        opening.include?("=") && !opening.start_with?("<%#")
       end
 
       #: (String) -> bool
diff --git a/lib/herb/ast/node.rb b/lib/herb/ast/node.rb
index e1b5768c6..c39f625d4 100644
--- a/lib/herb/ast/node.rb
+++ b/lib/herb/ast/node.rb
@@ -2,13 +2,21 @@
 # typed: true
 
 module Herb
+  #: type serialized_node = {
+  #|  type: String,
+  #|  location: serialized_location?,
+  #|  errors: Array[serialized_error]
+  #| }
   module AST
     class Node
-      attr_reader :type #: String
-      attr_reader :location #: Location
-      attr_reader :errors #: Array[Herb::Errors::Error]
-
-      #: (String, Location, Array[Herb::Errors::Error]) -> void
+      #: String
+      attr_reader :type
+      #: Location
+      attr_reader :location
+      #: Array[Herb::Errors::Error]
+      attr_reader :errors
+
+      #: (String, Location, ?Array[Herb::Errors::Error]) -> void
       def initialize(type, location, errors = [])
         @type = type
         @location = location
@@ -19,7 +27,7 @@ def initialize(type, location, errors = [])
       def to_hash
         {
           type: type,
-          location: location&.to_hash,
+          location: location.to_hash,
           errors: errors.map(&:to_hash),
         }
       end
diff --git a/lib/herb/engine.rb b/lib/herb/engine.rb
index 92b7fdcce..c619bae0a 100644
--- a/lib/herb/engine.rb
+++ b/lib/herb/engine.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+# typed: false
 
 require "json"
 require "time"
diff --git a/lib/herb/engine/debug_visitor.rb b/lib/herb/engine/debug_visitor.rb
index 87515e728..81334079f 100644
--- a/lib/herb/engine/debug_visitor.rb
+++ b/lib/herb/engine/debug_visitor.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+# typed: false
 
 module Herb
   class Engine
@@ -31,6 +32,7 @@ def initialize(file_path: nil, project_path: nil)
         @in_html_comment = false
         @in_html_doctype = false
         @erb_nodes_to_wrap = [] #: Array[Herb::AST::ERBContentNode]
+        @top_level_elements = [] #: Array[Herb::AST::HTMLElementNode]
       end
 
       def visit_document_node(node)
@@ -149,8 +151,6 @@ def replace_erb_nodes_recursive(node)
       end
 
       def find_top_level_elements(document_node)
-        @top_level_elements = [] #: Array[Herb::AST::HTMLElementNode]
-
         document_node.children.each do |child|
           @top_level_elements << child if child.is_a?(Herb::AST::HTMLElementNode)
         end
diff --git a/lib/herb/lex_result.rb b/lib/herb/lex_result.rb
index 5c32a76d1..e7b0d15cc 100644
--- a/lib/herb/lex_result.rb
+++ b/lib/herb/lex_result.rb
@@ -1,8 +1,10 @@
 # frozen_string_literal: true
+# typed: true
 
 module Herb
   class LexResult < Result
-    attr_reader :value #: TokenList
+    #: TokenList
+    attr_reader :value
 
     #: (Array[Herb::Token], String, Array[Herb::Warnings::Warning], Array[Herb::Errors::Error]) -> void
     def initialize(value, source, warnings, errors)
diff --git a/lib/herb/location.rb b/lib/herb/location.rb
index 276ce61aa..1474adf57 100644
--- a/lib/herb/location.rb
+++ b/lib/herb/location.rb
@@ -2,9 +2,15 @@
 # typed: true
 
 module Herb
+  #: type serialized_location = {
+  #| start: serialized_position,
+  #| end: serialized_position
+  #| }
   class Location
-    attr_reader :start #: Position
-    attr_reader :end #: Position
+    #: Position
+    attr_reader :start
+    #: Position
+    attr_reader :end
 
     #: (Position, Position) -> void
     def initialize(start_position, end_position)
@@ -28,9 +34,9 @@ def self.[](start_line, start_column, end_line, end_column)
     #: () -> serialized_location
     def to_hash
       {
-        start: start,
-        end: self.end,
-      } #: Herb::serialized_location
+        start: start.to_hash,
+        end: self.end.to_hash,
+      }
     end
 
     #: (?untyped) -> String
diff --git a/lib/herb/parse_result.rb b/lib/herb/parse_result.rb
index d86df34f7..d5679064f 100644
--- a/lib/herb/parse_result.rb
+++ b/lib/herb/parse_result.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+# typed: true
 
 require "json"
 
diff --git a/lib/herb/result.rb b/lib/herb/result.rb
index 9067e2843..1b0356b44 100644
--- a/lib/herb/result.rb
+++ b/lib/herb/result.rb
@@ -3,9 +3,12 @@
 
 module Herb
   class Result
-    attr_reader :source #: String
-    attr_reader :warnings #: Array[Herb::Warnings::Warning]
-    attr_reader :errors #: Array[Herb::Errors::Error]
+    #: String
+    attr_reader :source
+    #: Array[Herb::Warnings::Warning]
+    attr_reader :warnings
+    #: Array[Herb::Errors::Error]
+    attr_reader :errors
 
     #: (String, Array[Herb::Warnings::Warning], Array[Herb::Errors::Error]) -> void
     def initialize(source, warnings, errors)
diff --git a/lib/herb/token.rb b/lib/herb/token.rb
index 33742fe5a..16b6282f1 100644
--- a/lib/herb/token.rb
+++ b/lib/herb/token.rb
@@ -2,6 +2,12 @@
 # typed: true
 
 module Herb
+  #: type serialized_token = {
+  #|  value: String,
+  #|  range: serialized_range?,
+  #|  location: serialized_location?,
+  #|  type: String
+  #| }
   class Token
     include Colors
 
@@ -25,7 +31,7 @@ def to_hash
         range: range&.to_a,
         location: location&.to_hash,
         type: type,
-      } #: Herb::serialized_token
+      }
     end
 
     #: (?untyped) -> String
diff --git a/lib/herb/warnings.rb b/lib/herb/warnings.rb
index 9020a3d7d..950effd54 100644
--- a/lib/herb/warnings.rb
+++ b/lib/herb/warnings.rb
@@ -3,10 +3,18 @@
 
 module Herb
   module Warnings
+    #: type serialized_warning = {
+    #|  type: String,
+    #|  location: serialized_location?,
+    #|  message: String
+    #| }
     class Warning
-      attr_reader :type #: String
-      attr_reader :location #: Location
-      attr_reader :message #: String
+      #: String
+      attr_reader :type
+      #: Location?
+      attr_reader :location
+      #: String
+      attr_reader :message
 
       #: (String, Location, String) -> void
       def initialize(type, location, message)
diff --git a/sig/herb/ast/helpers.rbs b/sig/herb/ast/helpers.rbs
index 0db42b8b6..03efb9642 100644
--- a/sig/herb/ast/helpers.rbs
+++ b/sig/herb/ast/helpers.rbs
@@ -3,7 +3,7 @@
 module Herb
   module AST
     module Helpers
-      # : (Herb::AST::Node) -> bool
+      # : (Herb::AST::Node?) -> bool
       def erb_outputs?: (Herb::AST::Node) -> bool
 
       # : (String) -> bool
diff --git a/sig/herb/token.rbs b/sig/herb/token.rbs
index ea8d71937..59f580545 100644
--- a/sig/herb/token.rbs
+++ b/sig/herb/token.rbs
@@ -6,9 +6,9 @@ module Herb
 
     attr_reader value: String
 
-    attr_reader range: Range
+    attr_reader range: Range?
 
-    attr_reader location: Location
+    attr_reader location: Location?
 
     attr_reader type: String
 
diff --git a/sorbet/config b/sorbet/config
index a215ea13d..af3793756 100644
--- a/sorbet/config
+++ b/sorbet/config
@@ -1,3 +1,5 @@
+--dir
+lib/
 --ignore=/tmp/
 --ignore=/vendor/bundle
 --enable-experimental-rbs-comments
diff --git a/templates/lib/herb/ast/nodes.rb.erb b/templates/lib/herb/ast/nodes.rb.erb
index 719cbb1c2..262ccd100 100644
--- a/templates/lib/herb/ast/nodes.rb.erb
+++ b/templates/lib/herb/ast/nodes.rb.erb
@@ -1,11 +1,19 @@
 module Herb
   module AST
     <%- nodes.each do |node| -%>
+    #: type serialized_<%= node.human %> = {
+      <%- node.fields.each do |field| -%>
+      <%- is_nilable = !%w[Array[Herb::AST::Node] Array[Herb::AST::ERBWhenNode] Array[Herb::AST::ERBInNode] bool nil].include?(field.ruby_type) -%>
+    #|  <%= field.name %>: <%= field.ruby_type %><%= if is_nilable then "?" end %>,
+      <%- end -%>
+    #| }
     class <%= node.name -%> < Node
       include Colors
 
       <%- node.fields.each do |field| -%>
-      attr_reader :<%= field.name %> #: <%= field.ruby_type %>
+      <%- is_nilable = !%w[Array[Herb::AST::Node] Array[Herb::AST::ERBWhenNode] Array[Herb::AST::ERBInNode] bool nil].include?(field.ruby_type) -%>
+      #: <%= field.ruby_type %><%= if is_nilable then "?" end %>
+      attr_reader :<%= field.name %>
       <%- end -%>
 
       #: (<%= ["String", "Location", "Array[Herb::Errors::Error]", *node.fields.map(&:ruby_type)].join(", ") %>) -> void
@@ -26,7 +34,7 @@ module Herb
           <%- node.fields.each do |field| -%>
           <%= field.name %>: <%= field.name %>,
           <%- end -%>
-        }) #: Herb::serialized_<%= node.human %>
+        })
       end
 
       #: (Visitor) -> void
diff --git a/templates/lib/herb/errors.rb.erb b/templates/lib/herb/errors.rb.erb
index c8bac9b78..bdf227e18 100644
--- a/templates/lib/herb/errors.rb.erb
+++ b/templates/lib/herb/errors.rb.erb
@@ -1,9 +1,15 @@
-<%- base_arguments = [["type", "String"], ["location", "Location"], ["message", "String"]] -%>
+<%- base_arguments = [["type", "String"], ["location", "Location?"], ["message", "String"]] -%>
 module Herb
+  #: type serialized_error = {
+  #|  type: String,
+  #|  location: serialized_location?,
+  #|  message: String
+  #| }
   module Errors
     class Error
       <%- base_arguments.each do |argument, type| -%>
-      attr_reader :<%= argument %> #: <%= type %>
+      #: <%= type %>
+      attr_reader :<%= argument %>
       <%- end -%>
 
       #: (<%= base_arguments.map { |_argument, type| type }.join(", ") %>) -> void
@@ -49,7 +55,13 @@ module Herb
       <%- if error.fields.any? -%>
 
       <%- error.fields.each do |field| -%>
-      attr_reader :<%= field.name %> #: <%= field.ruby_type %>
+      #|  <%= "#{field.name}: #{field.ruby_type}?," %>
+      <%- end -%>
+      #| }
+
+      <%- error.fields.each do |field| -%>
+      #: <%= field.ruby_type %>?
+      attr_reader :<%= field.name %>
       <%- end -%>
 
       #: (<%= [*base_arguments.map(&:last), *error.fields.map(&:ruby_type)].join(", ") %>) -> void
diff --git a/templates/lib/herb/visitor.rb.erb b/templates/lib/herb/visitor.rb.erb
index 06bbe335a..e9e5d9ed5 100644
--- a/templates/lib/herb/visitor.rb.erb
+++ b/templates/lib/herb/visitor.rb.erb
@@ -2,12 +2,12 @@ module Herb
   class Visitor
     include AST::Helpers
 
-    #: (Herb::AST::Node) -> void
+    #: (Herb::AST::Node?) -> void
     def visit(node)
       node&.accept(self)
     end
 
-    #: (Array[Herb::AST::Node]) -> void
+    #: (Array[Herb::AST::Node?]) -> void
     def visit_all(nodes)
       nodes.each { |node| node&.accept(self) }
     end

From 105b4824fa920e08024db4106669d8861066537a Mon Sep 17 00:00:00 2001
From: Marco Roth <marco.roth@intergga.ch>
Date: Sat, 28 Feb 2026 17:04:11 +0100
Subject: [PATCH 3/3] Drop `--enable-experimental-rbs-comments` and let sorbet
 rely on `.rbs` files

---
 .github/workflows/build.yml         |   6 +-
 lib/herb/ast/node.rb                |   9 +-
 lib/herb/lex_result.rb              |   3 +-
 lib/herb/location.rb                |   6 +-
 lib/herb/position.rb                |   6 +-
 lib/herb/range.rb                   |   6 +-
 lib/herb/result.rb                  |   9 +-
 lib/herb/warnings.rb                |   9 +-
 sig/herb/ast/helpers.rbs            |   2 +-
 sig/herb/ast/node.rbs               |   9 +-
 sig/herb/ast/nodes.rbs              | 430 +++++++++++++++++++++-------
 sig/herb/errors.rbs                 | 167 +++++------
 sig/herb/location.rbs               |   4 +
 sig/herb/position.rbs               |   1 +
 sig/herb/range.rbs                  |   1 +
 sig/herb/token.rbs                  |  10 +-
 sig/herb/visitor.rbs                |   8 +-
 sig/herb/warnings.rbs               |   7 +-
 sorbet/config                       |   5 +-
 sorbet/rbi/prism.rbi                |   9 +
 templates/lib/herb/ast/nodes.rb.erb |   7 +-
 templates/lib/herb/errors.rb.erb    |   8 +-
 22 files changed, 474 insertions(+), 248 deletions(-)
 create mode 100644 sorbet/rbi/prism.rbi

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2ededbbef..c3f8170e7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -56,12 +56,12 @@ jobs:
       - name: Steep
         run: bundle exec steep check
 
-      - name: RBS Inline
-        run: bundle exec rake rbs_inline
-
       - name: Sorbet
         run: bundle exec srb tc
 
+      - name: RBS Inline
+        run: bundle exec rake rbs_inline
+
       - name: clang-tidy version
         run: clang-tidy-21 --version
 
diff --git a/lib/herb/ast/node.rb b/lib/herb/ast/node.rb
index c39f625d4..78aa4b99b 100644
--- a/lib/herb/ast/node.rb
+++ b/lib/herb/ast/node.rb
@@ -9,12 +9,9 @@ module Herb
   #| }
   module AST
     class Node
-      #: String
-      attr_reader :type
-      #: Location
-      attr_reader :location
-      #: Array[Herb::Errors::Error]
-      attr_reader :errors
+      attr_reader :type #: String
+      attr_reader :location #: Location
+      attr_reader :errors #: Array[Herb::Errors::Error]
 
       #: (String, Location, ?Array[Herb::Errors::Error]) -> void
       def initialize(type, location, errors = [])
diff --git a/lib/herb/lex_result.rb b/lib/herb/lex_result.rb
index e7b0d15cc..58a691900 100644
--- a/lib/herb/lex_result.rb
+++ b/lib/herb/lex_result.rb
@@ -3,8 +3,7 @@
 
 module Herb
   class LexResult < Result
-    #: TokenList
-    attr_reader :value
+    attr_reader :value #: TokenList
 
     #: (Array[Herb::Token], String, Array[Herb::Warnings::Warning], Array[Herb::Errors::Error]) -> void
     def initialize(value, source, warnings, errors)
diff --git a/lib/herb/location.rb b/lib/herb/location.rb
index 1474adf57..f74688a31 100644
--- a/lib/herb/location.rb
+++ b/lib/herb/location.rb
@@ -7,10 +7,8 @@ module Herb
   #| end: serialized_position
   #| }
   class Location
-    #: Position
-    attr_reader :start
-    #: Position
-    attr_reader :end
+    attr_reader :start #: Position
+    attr_reader :end #: Position
 
     #: (Position, Position) -> void
     def initialize(start_position, end_position)
diff --git a/lib/herb/position.rb b/lib/herb/position.rb
index 1213b0355..a6d7404b3 100644
--- a/lib/herb/position.rb
+++ b/lib/herb/position.rb
@@ -4,10 +4,8 @@
 module Herb
   #: type serialized_position = { line: Integer, column: Integer }
   class Position
-    #: Integer
-    attr_reader :line
-    #: Integer
-    attr_reader :column
+    attr_reader :line #: Integer
+    attr_reader :column #: Integer
 
     #: (Integer, Integer) -> void
     def initialize(line, column)
diff --git a/lib/herb/range.rb b/lib/herb/range.rb
index edd15a8e9..749d36a89 100644
--- a/lib/herb/range.rb
+++ b/lib/herb/range.rb
@@ -4,10 +4,8 @@
 module Herb
   #: type serialized_range = [Integer, Integer]
   class Range
-    #: Integer
-    attr_reader :from
-    #: Integer
-    attr_reader :to
+    attr_reader :from #: Integer
+    attr_reader :to #: Integer
 
     #: (Integer, Integer) -> void
     def initialize(from, to)
diff --git a/lib/herb/result.rb b/lib/herb/result.rb
index 1b0356b44..9067e2843 100644
--- a/lib/herb/result.rb
+++ b/lib/herb/result.rb
@@ -3,12 +3,9 @@
 
 module Herb
   class Result
-    #: String
-    attr_reader :source
-    #: Array[Herb::Warnings::Warning]
-    attr_reader :warnings
-    #: Array[Herb::Errors::Error]
-    attr_reader :errors
+    attr_reader :source #: String
+    attr_reader :warnings #: Array[Herb::Warnings::Warning]
+    attr_reader :errors #: Array[Herb::Errors::Error]
 
     #: (String, Array[Herb::Warnings::Warning], Array[Herb::Errors::Error]) -> void
     def initialize(source, warnings, errors)
diff --git a/lib/herb/warnings.rb b/lib/herb/warnings.rb
index 950effd54..565f4848e 100644
--- a/lib/herb/warnings.rb
+++ b/lib/herb/warnings.rb
@@ -9,12 +9,9 @@ module Warnings
     #|  message: String
     #| }
     class Warning
-      #: String
-      attr_reader :type
-      #: Location?
-      attr_reader :location
-      #: String
-      attr_reader :message
+      attr_reader :type #: String
+      attr_reader :location #: Location?
+      attr_reader :message #: String
 
       #: (String, Location, String) -> void
       def initialize(type, location, message)
diff --git a/sig/herb/ast/helpers.rbs b/sig/herb/ast/helpers.rbs
index 03efb9642..a5ba41e11 100644
--- a/sig/herb/ast/helpers.rbs
+++ b/sig/herb/ast/helpers.rbs
@@ -4,7 +4,7 @@ module Herb
   module AST
     module Helpers
       # : (Herb::AST::Node?) -> bool
-      def erb_outputs?: (Herb::AST::Node) -> bool
+      def erb_outputs?: (Herb::AST::Node?) -> bool
 
       # : (String) -> bool
       def erb_comment?: (String) -> bool
diff --git a/sig/herb/ast/node.rbs b/sig/herb/ast/node.rbs
index 7d52e7498..c505f4885 100644
--- a/sig/herb/ast/node.rbs
+++ b/sig/herb/ast/node.rbs
@@ -1,6 +1,11 @@
 # Generated from lib/herb/ast/node.rb with RBS::Inline
 
 module Herb
+  # : type serialized_node = {
+  # |  type: String,
+  # |  location: serialized_location?,
+  # |  errors: Array[serialized_error]
+  # | }
   module AST
     class Node
       attr_reader type: String
@@ -9,8 +14,8 @@ module Herb
 
       attr_reader errors: Array[Herb::Errors::Error]
 
-      # : (String, Location, Array[Herb::Errors::Error]) -> void
-      def initialize: (String, Location, Array[Herb::Errors::Error]) -> void
+      # : (String, Location, ?Array[Herb::Errors::Error]) -> void
+      def initialize: (String, Location, ?Array[Herb::Errors::Error]) -> void
 
       # : () -> serialized_node
       def to_hash: () -> serialized_node
diff --git a/sig/herb/ast/nodes.rbs b/sig/herb/ast/nodes.rbs
index 1b09fe1fd..df666d09c 100644
--- a/sig/herb/ast/nodes.rbs
+++ b/sig/herb/ast/nodes.rbs
@@ -2,6 +2,9 @@
 
 module Herb
   module AST
+    # : type serialized_document_node = {
+    # |  children: Array[Herb::AST::Node],
+    # | }
     class DocumentNode < Node
       include Colors
 
@@ -29,10 +32,13 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_literal_node = {
+    # |  content: String?,
+    # | }
     class LiteralNode < Node
       include Colors
 
-      attr_reader content: String
+      attr_reader content: String?
 
       # : (String, Location, Array[Herb::Errors::Error], String) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], String) -> void
@@ -56,14 +62,21 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_open_tag_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  tag_name: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  is_void: bool,
+    # | }
     class HTMLOpenTagNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
@@ -91,12 +104,17 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_conditional_open_tag_node = {
+    # |  conditional: (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode)?,
+    # |  tag_name: Herb::Token?,
+    # |  is_void: bool,
+    # | }
     class HTMLConditionalOpenTagNode < Node
       include Colors
 
-      attr_reader conditional: Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode
+      attr_reader conditional: (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode)?
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
       attr_reader is_void: bool
 
@@ -122,16 +140,22 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_close_tag_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  tag_name: Herb::Token?,
+    # |  children: Array[Herb::AST::WhitespaceNode]?,
+    # |  tag_closing: Herb::Token?,
+    # | }
     class HTMLCloseTagNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
-      attr_reader children: Array[Herb::AST::WhitespaceNode]
+      attr_reader children: Array[Herb::AST::WhitespaceNode]?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Array[Herb::AST::WhitespaceNode], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Array[Herb::AST::WhitespaceNode], Herb::Token) -> void
@@ -155,10 +179,13 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_omitted_close_tag_node = {
+    # |  tag_name: Herb::Token?,
+    # | }
     class HTMLOmittedCloseTagNode < Node
       include Colors
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token) -> void
@@ -182,20 +209,28 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_element_node = {
+    # |  open_tag: (Herb::AST::HTMLOpenTagNode | Herb::AST::HTMLConditionalOpenTagNode)?,
+    # |  tag_name: Herb::Token?,
+    # |  body: Array[Herb::AST::Node],
+    # |  close_tag: (Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode)?,
+    # |  is_void: bool,
+    # |  source: String?,
+    # | }
     class HTMLElementNode < Node
       include Colors
 
-      attr_reader open_tag: Herb::AST::HTMLOpenTagNode | Herb::AST::HTMLConditionalOpenTagNode
+      attr_reader open_tag: (Herb::AST::HTMLOpenTagNode | Herb::AST::HTMLConditionalOpenTagNode)?
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
       attr_reader body: Array[Herb::AST::Node]
 
-      attr_reader close_tag: Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode
+      attr_reader close_tag: (Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode)?
 
       attr_reader is_void: bool
 
-      attr_reader source: String
+      attr_reader source: String?
 
       # : (String, Location, Array[Herb::Errors::Error], (Herb::AST::HTMLOpenTagNode | Herb::AST::HTMLConditionalOpenTagNode), Herb::Token, Array[Herb::AST::Node], (Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode), bool, String) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::AST::HTMLOpenTagNode | Herb::AST::HTMLConditionalOpenTagNode, Herb::Token, Array[Herb::AST::Node], Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode, bool, String) -> void
@@ -219,24 +254,34 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_conditional_element_node = {
+    # |  condition: String?,
+    # |  open_conditional: (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode)?,
+    # |  open_tag: Herb::AST::HTMLOpenTagNode?,
+    # |  body: Array[Herb::AST::Node],
+    # |  close_tag: (Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode)?,
+    # |  close_conditional: (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode)?,
+    # |  tag_name: Herb::Token?,
+    # |  source: String?,
+    # | }
     class HTMLConditionalElementNode < Node
       include Colors
 
-      attr_reader condition: String
+      attr_reader condition: String?
 
-      attr_reader open_conditional: Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode
+      attr_reader open_conditional: (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode)?
 
-      attr_reader open_tag: Herb::AST::HTMLOpenTagNode
+      attr_reader open_tag: Herb::AST::HTMLOpenTagNode?
 
       attr_reader body: Array[Herb::AST::Node]
 
-      attr_reader close_tag: Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode
+      attr_reader close_tag: (Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode)?
 
-      attr_reader close_conditional: Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode
+      attr_reader close_conditional: (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode)?
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
-      attr_reader source: String
+      attr_reader source: String?
 
       # : (String, Location, Array[Herb::Errors::Error], String, (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode), Herb::AST::HTMLOpenTagNode, Array[Herb::AST::Node], (Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode), (Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode), Herb::Token, String) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], String, Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode, Herb::AST::HTMLOpenTagNode, Array[Herb::AST::Node], Herb::AST::HTMLCloseTagNode | Herb::AST::HTMLOmittedCloseTagNode, Herb::AST::ERBIfNode | Herb::AST::ERBUnlessNode, Herb::Token, String) -> void
@@ -260,14 +305,20 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_attribute_value_node = {
+    # |  open_quote: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  close_quote: Herb::Token?,
+    # |  quoted: bool,
+    # | }
     class HTMLAttributeValueNode < Node
       include Colors
 
-      attr_reader open_quote: Herb::Token
+      attr_reader open_quote: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
-      attr_reader close_quote: Herb::Token
+      attr_reader close_quote: Herb::Token?
 
       attr_reader quoted: bool
 
@@ -293,10 +344,13 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_attribute_name_node = {
+    # |  children: Array[(Herb::AST::LiteralNode | Herb::AST::ERBContentNode)]?,
+    # | }
     class HTMLAttributeNameNode < Node
       include Colors
 
-      attr_reader children: Array[Herb::AST::LiteralNode | Herb::AST::ERBContentNode]
+      attr_reader children: Array[Herb::AST::LiteralNode | Herb::AST::ERBContentNode]?
 
       # : (String, Location, Array[Herb::Errors::Error], Array[(Herb::AST::LiteralNode | Herb::AST::ERBContentNode)]) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Array[Herb::AST::LiteralNode | Herb::AST::ERBContentNode]) -> void
@@ -320,14 +374,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_attribute_node = {
+    # |  name: Herb::AST::HTMLAttributeNameNode?,
+    # |  equals: Herb::Token?,
+    # |  value: Herb::AST::HTMLAttributeValueNode?,
+    # | }
     class HTMLAttributeNode < Node
       include Colors
 
-      attr_reader name: Herb::AST::HTMLAttributeNameNode
+      attr_reader name: Herb::AST::HTMLAttributeNameNode?
 
-      attr_reader equals: Herb::Token
+      attr_reader equals: Herb::Token?
 
-      attr_reader value: Herb::AST::HTMLAttributeValueNode
+      attr_reader value: Herb::AST::HTMLAttributeValueNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::AST::HTMLAttributeNameNode, Herb::Token, Herb::AST::HTMLAttributeValueNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::AST::HTMLAttributeNameNode, Herb::Token, Herb::AST::HTMLAttributeValueNode) -> void
@@ -351,10 +410,13 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_text_node = {
+    # |  content: String?,
+    # | }
     class HTMLTextNode < Node
       include Colors
 
-      attr_reader content: String
+      attr_reader content: String?
 
       # : (String, Location, Array[Herb::Errors::Error], String) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], String) -> void
@@ -378,14 +440,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_comment_node = {
+    # |  comment_start: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  comment_end: Herb::Token?,
+    # | }
     class HTMLCommentNode < Node
       include Colors
 
-      attr_reader comment_start: Herb::Token
+      attr_reader comment_start: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
-      attr_reader comment_end: Herb::Token
+      attr_reader comment_end: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
@@ -409,14 +476,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_html_doctype_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  tag_closing: Herb::Token?,
+    # | }
     class HTMLDoctypeNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
@@ -440,14 +512,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_xml_declaration_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  tag_closing: Herb::Token?,
+    # | }
     class XMLDeclarationNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
@@ -471,14 +548,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_cdata_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  tag_closing: Herb::Token?,
+    # | }
     class CDATANode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Array[Herb::AST::Node], Herb::Token) -> void
@@ -502,10 +584,13 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_whitespace_node = {
+    # |  value: Herb::Token?,
+    # | }
     class WhitespaceNode < Node
       include Colors
 
-      attr_reader value: Herb::Token
+      attr_reader value: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token) -> void
@@ -529,14 +614,22 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_content_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  analyzed_ruby: nil,
+    # |  parsed: bool,
+    # |  valid: bool,
+    # | }
     class ERBContentNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader analyzed_ruby: nil
 
@@ -566,14 +659,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_end_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # | }
     class ERBEndNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token) -> void
@@ -597,14 +695,20 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_else_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # | }
     class ERBElseNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
@@ -630,22 +734,31 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_if_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  then_keyword: Herb::Location?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  subsequent: (Herb::AST::ERBIfNode | Herb::AST::ERBElseNode)?,
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBIfNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
-      attr_reader then_keyword: Herb::Location
+      attr_reader then_keyword: Herb::Location?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader subsequent: Herb::AST::ERBIfNode | Herb::AST::ERBElseNode
+      attr_reader subsequent: (Herb::AST::ERBIfNode | Herb::AST::ERBElseNode)?
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Herb::Location, Array[Herb::AST::Node], (Herb::AST::ERBIfNode | Herb::AST::ERBElseNode), Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Herb::Location, Array[Herb::AST::Node], Herb::AST::ERBIfNode | Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
@@ -669,18 +782,25 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_block_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  body: Array[Herb::AST::Node],
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBBlockNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader body: Array[Herb::AST::Node]
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
@@ -704,16 +824,23 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_when_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  then_keyword: Herb::Location?,
+    # |  statements: Array[Herb::AST::Node],
+    # | }
     class ERBWhenNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
-      attr_reader then_keyword: Herb::Location
+      attr_reader then_keyword: Herb::Location?
 
       attr_reader statements: Array[Herb::AST::Node]
 
@@ -739,22 +866,31 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_case_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  conditions: Array[Herb::AST::ERBWhenNode],
+    # |  else_clause: Herb::AST::ERBElseNode?,
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBCaseNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
       attr_reader conditions: Array[Herb::AST::ERBWhenNode]
 
-      attr_reader else_clause: Herb::AST::ERBElseNode
+      attr_reader else_clause: Herb::AST::ERBElseNode?
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Array[Herb::AST::ERBWhenNode], Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Array[Herb::AST::ERBWhenNode], Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
@@ -778,22 +914,31 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_case_match_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  children: Array[Herb::AST::Node],
+    # |  conditions: Array[Herb::AST::ERBInNode],
+    # |  else_clause: Herb::AST::ERBElseNode?,
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBCaseMatchNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader children: Array[Herb::AST::Node]
 
       attr_reader conditions: Array[Herb::AST::ERBInNode]
 
-      attr_reader else_clause: Herb::AST::ERBElseNode
+      attr_reader else_clause: Herb::AST::ERBElseNode?
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Array[Herb::AST::ERBInNode], Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Array[Herb::AST::ERBInNode], Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
@@ -817,18 +962,25 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_while_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBWhileNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
@@ -852,18 +1004,25 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_until_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBUntilNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
@@ -887,18 +1046,25 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_for_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBForNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBEndNode) -> void
@@ -922,18 +1088,25 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_rescue_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  subsequent: Herb::AST::ERBRescueNode?,
+    # | }
     class ERBRescueNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader subsequent: Herb::AST::ERBRescueNode
+      attr_reader subsequent: Herb::AST::ERBRescueNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBRescueNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBRescueNode) -> void
@@ -957,14 +1130,20 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_ensure_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # | }
     class ERBEnsureNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
@@ -990,24 +1169,34 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_begin_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  rescue_clause: Herb::AST::ERBRescueNode?,
+    # |  else_clause: Herb::AST::ERBElseNode?,
+    # |  ensure_clause: Herb::AST::ERBEnsureNode?,
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBBeginNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader rescue_clause: Herb::AST::ERBRescueNode
+      attr_reader rescue_clause: Herb::AST::ERBRescueNode?
 
-      attr_reader else_clause: Herb::AST::ERBElseNode
+      attr_reader else_clause: Herb::AST::ERBElseNode?
 
-      attr_reader ensure_clause: Herb::AST::ERBEnsureNode
+      attr_reader ensure_clause: Herb::AST::ERBEnsureNode?
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBRescueNode, Herb::AST::ERBElseNode, Herb::AST::ERBEnsureNode, Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Array[Herb::AST::Node], Herb::AST::ERBRescueNode, Herb::AST::ERBElseNode, Herb::AST::ERBEnsureNode, Herb::AST::ERBEndNode) -> void
@@ -1031,22 +1220,31 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_unless_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  then_keyword: Herb::Location?,
+    # |  statements: Array[Herb::AST::Node],
+    # |  else_clause: Herb::AST::ERBElseNode?,
+    # |  end_node: Herb::AST::ERBEndNode?,
+    # | }
     class ERBUnlessNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
-      attr_reader then_keyword: Herb::Location
+      attr_reader then_keyword: Herb::Location?
 
       attr_reader statements: Array[Herb::AST::Node]
 
-      attr_reader else_clause: Herb::AST::ERBElseNode
+      attr_reader else_clause: Herb::AST::ERBElseNode?
 
-      attr_reader end_node: Herb::AST::ERBEndNode
+      attr_reader end_node: Herb::AST::ERBEndNode?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Herb::Location, Array[Herb::AST::Node], Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token, Herb::Location, Array[Herb::AST::Node], Herb::AST::ERBElseNode, Herb::AST::ERBEndNode) -> void
@@ -1070,14 +1268,19 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_yield_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # | }
     class ERBYieldNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
       # : (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token) -> void
       def initialize: (String, Location, Array[Herb::Errors::Error], Herb::Token, Herb::Token, Herb::Token) -> void
@@ -1101,16 +1304,23 @@ module Herb
       def tree_inspect: (?indent: Integer, ?depth: Integer, ?depth_limit: Integer) -> String
     end
 
+    # : type serialized_erb_in_node = {
+    # |  tag_opening: Herb::Token?,
+    # |  content: Herb::Token?,
+    # |  tag_closing: Herb::Token?,
+    # |  then_keyword: Herb::Location?,
+    # |  statements: Array[Herb::AST::Node],
+    # | }
     class ERBInNode < Node
       include Colors
 
-      attr_reader tag_opening: Herb::Token
+      attr_reader tag_opening: Herb::Token?
 
-      attr_reader content: Herb::Token
+      attr_reader content: Herb::Token?
 
-      attr_reader tag_closing: Herb::Token
+      attr_reader tag_closing: Herb::Token?
 
-      attr_reader then_keyword: Herb::Location
+      attr_reader then_keyword: Herb::Location?
 
       attr_reader statements: Array[Herb::AST::Node]
 
diff --git a/sig/herb/errors.rbs b/sig/herb/errors.rbs
index d10cae911..abb892758 100644
--- a/sig/herb/errors.rbs
+++ b/sig/herb/errors.rbs
@@ -1,16 +1,21 @@
 # Generated from lib/herb/errors.rb with RBS::Inline
 
 module Herb
+  # : type serialized_error = {
+  # |  type: String,
+  # |  location: serialized_location?,
+  # |  message: String
+  # | }
   module Errors
     class Error
       attr_reader type: String
 
-      attr_reader location: Location
+      attr_reader location: Location?
 
       attr_reader message: String
 
-      # : (String, Location, String) -> void
-      def initialize: (String, Location, String) -> void
+      # : (String, Location?, String) -> void
+      def initialize: (String, Location?, String) -> void
 
       # : () -> serialized_error
       def to_hash: () -> serialized_error
@@ -31,14 +36,14 @@ module Herb
     class UnexpectedError < Error
       include Colors
 
-      attr_reader description: String
+      attr_reader description: String?
 
-      attr_reader expected: String
+      attr_reader expected: String?
 
-      attr_reader found: String
+      attr_reader found: String?
 
-      # : (String, Location, String, String, String, String) -> void
-      def initialize: (String, Location, String, String, String, String) -> void
+      # : (String, Location?, String, String, String, String) -> void
+      def initialize: (String, Location?, String, String, String, String) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -53,12 +58,12 @@ module Herb
     class UnexpectedTokenError < Error
       include Colors
 
-      attr_reader expected_type: String
+      attr_reader expected_type: String?
 
-      attr_reader found: Herb::Token
+      attr_reader found: Herb::Token?
 
-      # : (String, Location, String, String, Herb::Token) -> void
-      def initialize: (String, Location, String, String, Herb::Token) -> void
+      # : (String, Location?, String, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -73,10 +78,10 @@ module Herb
     class MissingOpeningTagError < Error
       include Colors
 
-      attr_reader closing_tag: Herb::Token
+      attr_reader closing_tag: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -91,10 +96,10 @@ module Herb
     class MissingClosingTagError < Error
       include Colors
 
-      attr_reader opening_tag: Herb::Token
+      attr_reader opening_tag: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -109,12 +114,12 @@ module Herb
     class TagNamesMismatchError < Error
       include Colors
 
-      attr_reader opening_tag: Herb::Token
+      attr_reader opening_tag: Herb::Token?
 
-      attr_reader closing_tag: Herb::Token
+      attr_reader closing_tag: Herb::Token?
 
-      # : (String, Location, String, Herb::Token, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -129,14 +134,14 @@ module Herb
     class VoidElementClosingTagError < Error
       include Colors
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
-      attr_reader expected: String
+      attr_reader expected: String?
 
-      attr_reader found: String
+      attr_reader found: String?
 
-      # : (String, Location, String, Herb::Token, String, String) -> void
-      def initialize: (String, Location, String, Herb::Token, String, String) -> void
+      # : (String, Location?, String, Herb::Token, String, String) -> void
+      def initialize: (String, Location?, String, Herb::Token, String, String) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -151,10 +156,10 @@ module Herb
     class UnclosedElementError < Error
       include Colors
 
-      attr_reader opening_tag: Herb::Token
+      attr_reader opening_tag: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -169,14 +174,14 @@ module Herb
     class RubyParseError < Error
       include Colors
 
-      attr_reader error_message: String
+      attr_reader error_message: String?
 
-      attr_reader diagnostic_id: String
+      attr_reader diagnostic_id: String?
 
-      attr_reader level: String
+      attr_reader level: String?
 
-      # : (String, Location, String, String, String, String) -> void
-      def initialize: (String, Location, String, String, String, String) -> void
+      # : (String, Location?, String, String, String, String) -> void
+      def initialize: (String, Location?, String, String, String, String) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -191,10 +196,10 @@ module Herb
     class ERBControlFlowScopeError < Error
       include Colors
 
-      attr_reader keyword: String
+      attr_reader keyword: String?
 
-      # : (String, Location, String, String) -> void
-      def initialize: (String, Location, String, String) -> void
+      # : (String, Location?, String, String) -> void
+      def initialize: (String, Location?, String, String) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -209,10 +214,10 @@ module Herb
     class MissingERBEndTagError < Error
       include Colors
 
-      attr_reader keyword: String
+      attr_reader keyword: String?
 
-      # : (String, Location, String, String) -> void
-      def initialize: (String, Location, String, String) -> void
+      # : (String, Location?, String, String) -> void
+      def initialize: (String, Location?, String, String) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -247,12 +252,12 @@ module Herb
     class ConditionalElementMultipleTagsError < Error
       include Colors
 
-      attr_reader line: Integer
+      attr_reader line: Integer?
 
-      attr_reader column: Integer
+      attr_reader column: Integer?
 
-      # : (String, Location, String, Integer, Integer) -> void
-      def initialize: (String, Location, String, Integer, Integer) -> void
+      # : (String, Location?, String, Integer, Integer) -> void
+      def initialize: (String, Location?, String, Integer, Integer) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -267,22 +272,22 @@ module Herb
     class ConditionalElementConditionMismatchError < Error
       include Colors
 
-      attr_reader tag_name: String
+      attr_reader tag_name: String?
 
-      attr_reader open_condition: String
+      attr_reader open_condition: String?
 
-      attr_reader open_line: Integer
+      attr_reader open_line: Integer?
 
-      attr_reader open_column: Integer
+      attr_reader open_column: Integer?
 
-      attr_reader close_condition: String
+      attr_reader close_condition: String?
 
-      attr_reader close_line: Integer
+      attr_reader close_line: Integer?
 
-      attr_reader close_column: Integer
+      attr_reader close_column: Integer?
 
-      # : (String, Location, String, String, String, Integer, Integer, String, Integer, Integer) -> void
-      def initialize: (String, Location, String, String, String, Integer, Integer, String, Integer, Integer) -> void
+      # : (String, Location?, String, String, String, Integer, Integer, String, Integer, Integer) -> void
+      def initialize: (String, Location?, String, String, String, Integer, Integer, String, Integer, Integer) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -297,10 +302,10 @@ module Herb
     class InvalidCommentClosingTagError < Error
       include Colors
 
-      attr_reader closing_tag: Herb::Token
+      attr_reader closing_tag: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -315,12 +320,12 @@ module Herb
     class OmittedClosingTagError < Error
       include Colors
 
-      attr_reader opening_tag: Herb::Token
+      attr_reader opening_tag: Herb::Token?
 
-      attr_reader insertion_point: Herb::Position
+      attr_reader insertion_point: Herb::Position?
 
-      # : (String, Location, String, Herb::Token, Herb::Position) -> void
-      def initialize: (String, Location, String, Herb::Token, Herb::Position) -> void
+      # : (String, Location?, String, Herb::Token, Herb::Position) -> void
+      def initialize: (String, Location?, String, Herb::Token, Herb::Position) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -335,10 +340,10 @@ module Herb
     class UnclosedOpenTagError < Error
       include Colors
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -353,10 +358,10 @@ module Herb
     class UnclosedCloseTagError < Error
       include Colors
 
-      attr_reader tag_name: Herb::Token
+      attr_reader tag_name: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -371,10 +376,10 @@ module Herb
     class UnclosedQuoteError < Error
       include Colors
 
-      attr_reader opening_quote: Herb::Token
+      attr_reader opening_quote: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -389,10 +394,10 @@ module Herb
     class MissingAttributeValueError < Error
       include Colors
 
-      attr_reader attribute_name: String
+      attr_reader attribute_name: String?
 
-      # : (String, Location, String, String) -> void
-      def initialize: (String, Location, String, String) -> void
+      # : (String, Location?, String, String) -> void
+      def initialize: (String, Location?, String, String) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -407,10 +412,10 @@ module Herb
     class UnclosedERBTagError < Error
       include Colors
 
-      attr_reader opening_tag: Herb::Token
+      attr_reader opening_tag: Herb::Token?
 
-      # : (String, Location, String, Herb::Token) -> void
-      def initialize: (String, Location, String, Herb::Token) -> void
+      # : (String, Location?, String, Herb::Token) -> void
+      def initialize: (String, Location?, String, Herb::Token) -> void
 
       # : () -> String
       def inspect: () -> String
@@ -435,14 +440,14 @@ module Herb
     class NestedERBTagError < Error
       include Colors
 
-      attr_reader opening_tag: Herb::Token
+      attr_reader opening_tag: Herb::Token?
 
-      attr_reader nested_tag_line: Integer
+      attr_reader nested_tag_line: Integer?
 
-      attr_reader nested_tag_column: Integer
+      attr_reader nested_tag_column: Integer?
 
-      # : (String, Location, String, Herb::Token, Integer, Integer) -> void
-      def initialize: (String, Location, String, Herb::Token, Integer, Integer) -> void
+      # : (String, Location?, String, Herb::Token, Integer, Integer) -> void
+      def initialize: (String, Location?, String, Herb::Token, Integer, Integer) -> void
 
       # : () -> String
       def inspect: () -> String
diff --git a/sig/herb/location.rbs b/sig/herb/location.rbs
index b10799f1d..71c2e3daa 100644
--- a/sig/herb/location.rbs
+++ b/sig/herb/location.rbs
@@ -1,6 +1,10 @@
 # Generated from lib/herb/location.rb with RBS::Inline
 
 module Herb
+  # : type serialized_location = {
+  # | start: serialized_position,
+  # | end: serialized_position
+  # | }
   class Location
     attr_reader start: Position
 
diff --git a/sig/herb/position.rbs b/sig/herb/position.rbs
index cb0c33ee4..eeed348bb 100644
--- a/sig/herb/position.rbs
+++ b/sig/herb/position.rbs
@@ -1,6 +1,7 @@
 # Generated from lib/herb/position.rb with RBS::Inline
 
 module Herb
+  # : type serialized_position = { line: Integer, column: Integer }
   class Position
     attr_reader line: Integer
 
diff --git a/sig/herb/range.rbs b/sig/herb/range.rbs
index 9b6d02947..76a251338 100644
--- a/sig/herb/range.rbs
+++ b/sig/herb/range.rbs
@@ -1,6 +1,7 @@
 # Generated from lib/herb/range.rb with RBS::Inline
 
 module Herb
+  # : type serialized_range = [Integer, Integer]
   class Range
     attr_reader from: Integer
 
diff --git a/sig/herb/token.rbs b/sig/herb/token.rbs
index 59f580545..26d57e4c9 100644
--- a/sig/herb/token.rbs
+++ b/sig/herb/token.rbs
@@ -1,14 +1,20 @@
 # Generated from lib/herb/token.rb with RBS::Inline
 
 module Herb
+  # : type serialized_token = {
+  # |  value: String,
+  # |  range: serialized_range?,
+  # |  location: serialized_location?,
+  # |  type: String
+  # | }
   class Token
     include Colors
 
     attr_reader value: String
 
-    attr_reader range: Range?
+    attr_reader range: Range
 
-    attr_reader location: Location?
+    attr_reader location: Location
 
     attr_reader type: String
 
diff --git a/sig/herb/visitor.rbs b/sig/herb/visitor.rbs
index f3b50f371..6636bad70 100644
--- a/sig/herb/visitor.rbs
+++ b/sig/herb/visitor.rbs
@@ -4,11 +4,11 @@ module Herb
   class Visitor
     include AST::Helpers
 
-    # : (Herb::AST::Node) -> void
-    def visit: (Herb::AST::Node) -> void
+    # : (Herb::AST::Node?) -> void
+    def visit: (Herb::AST::Node?) -> void
 
-    # : (Array[Herb::AST::Node]) -> void
-    def visit_all: (Array[Herb::AST::Node]) -> void
+    # : (Array[Herb::AST::Node?]) -> void
+    def visit_all: (Array[Herb::AST::Node?]) -> void
 
     # : (Herb::AST::Node) -> void
     def visit_child_nodes: (Herb::AST::Node) -> void
diff --git a/sig/herb/warnings.rbs b/sig/herb/warnings.rbs
index 4da04d0eb..0c85d3f76 100644
--- a/sig/herb/warnings.rbs
+++ b/sig/herb/warnings.rbs
@@ -2,10 +2,15 @@
 
 module Herb
   module Warnings
+    # : type serialized_warning = {
+    # |  type: String,
+    # |  location: serialized_location?,
+    # |  message: String
+    # | }
     class Warning
       attr_reader type: String
 
-      attr_reader location: Location
+      attr_reader location: Location?
 
       attr_reader message: String
 
diff --git a/sorbet/config b/sorbet/config
index af3793756..a9538c8a0 100644
--- a/sorbet/config
+++ b/sorbet/config
@@ -1,5 +1,4 @@
---dir
-lib/
+--dir=lib/
+--dir=sorbet/rbi
 --ignore=/tmp/
 --ignore=/vendor/bundle
---enable-experimental-rbs-comments
diff --git a/sorbet/rbi/prism.rbi b/sorbet/rbi/prism.rbi
new file mode 100644
index 000000000..10eaa3aca
--- /dev/null
+++ b/sorbet/rbi/prism.rbi
@@ -0,0 +1,9 @@
+# typed: true
+
+# Shim for Prism::LexCompat which was removed in newer versions
+# but is still referenced in the vendored prism RBI files.
+module Prism
+  module LexCompat
+    Result = Prism::LexResult
+  end
+end
diff --git a/templates/lib/herb/ast/nodes.rb.erb b/templates/lib/herb/ast/nodes.rb.erb
index 262ccd100..d5a9e6d72 100644
--- a/templates/lib/herb/ast/nodes.rb.erb
+++ b/templates/lib/herb/ast/nodes.rb.erb
@@ -12,8 +12,7 @@ module Herb
 
       <%- node.fields.each do |field| -%>
       <%- is_nilable = !%w[Array[Herb::AST::Node] Array[Herb::AST::ERBWhenNode] Array[Herb::AST::ERBInNode] bool nil].include?(field.ruby_type) -%>
-      #: <%= field.ruby_type %><%= if is_nilable then "?" end %>
-      attr_reader :<%= field.name %>
+      attr_reader :<%= field.name %> #: <%= field.ruby_type %><%= if is_nilable then "?" end %>
       <%- end -%>
 
       #: (<%= ["String", "Location", "Array[Herb::Errors::Error]", *node.fields.map(&:ruby_type)].join(", ") %>) -> void
@@ -34,7 +33,7 @@ module Herb
           <%- node.fields.each do |field| -%>
           <%= field.name %>: <%= field.name %>,
           <%- end -%>
-        })
+        }) #: Herb::serialized_<%= node.human %>
       end
 
       #: (Visitor) -> void
@@ -48,7 +47,7 @@ module Herb
           if field.is_a?(Herb::Template::NodeField) || field.is_a?(Herb::Template::BorrowedNodeField)
             field.name
           elsif field.is_a?(Herb::Template::ArrayField) && (field.specific_kind&.end_with?("Node") || field.union_kind&.all? { |k| k.end_with?("Node") })
-            "*#{field.name}"
+            "*(#{field.name} || [])"
           else
             nil
           end
diff --git a/templates/lib/herb/errors.rb.erb b/templates/lib/herb/errors.rb.erb
index bdf227e18..0b42122f7 100644
--- a/templates/lib/herb/errors.rb.erb
+++ b/templates/lib/herb/errors.rb.erb
@@ -8,8 +8,7 @@ module Herb
   module Errors
     class Error
       <%- base_arguments.each do |argument, type| -%>
-      #: <%= type %>
-      attr_reader :<%= argument %>
+      attr_reader :<%= argument %> #: <%= type %>
       <%- end -%>
 
       #: (<%= base_arguments.map { |_argument, type| type }.join(", ") %>) -> void
@@ -60,8 +59,7 @@ module Herb
       #| }
 
       <%- error.fields.each do |field| -%>
-      #: <%= field.ruby_type %>?
-      attr_reader :<%= field.name %>
+      attr_reader :<%= field.name %> #: <%= field.ruby_type %>?
       <%- end -%>
 
       #: (<%= [*base_arguments.map(&:last), *error.fields.map(&:ruby_type)].join(", ") %>) -> void
@@ -93,7 +91,7 @@ module Herb
       def tree_inspect(indent: 0, depth: 0, depth_limit: 25)
         output = +""
 
-        output += white("@ #{bold(red(error_name))} #{dimmed("(location: #{location.tree_inspect})\n")}")
+        output += white("@ #{bold(red(error_name))} #{dimmed("(location: #{location&.tree_inspect})\n")}")
         <%- symbol = error.fields.none? ? "└──" : "├──" -%>
         output += white("<%= symbol %> message: #{green(message.inspect)}\n")
         <%- error.fields.each do |field| -%>