WIP

History.md

@@ -1,5 +1,38 @@
 # Liquid Change Log
 
+## 6.0.0
+
+### Architectural changes
+
+### Features
+* (TODO) Add support for boolean expressions everywhere
+  * As variable output `{{ a or b }}`
+  * As filter argument `{{ collection | where: 'prop', a or b }}`
+  * As tag argument `{% render 'snip', enabled: a or b %}`
+  * As conditional tag argument `{% if cond %}` (extending previous behaviour)
+* (TODO) Add support for subexpression prioritization and associativity
+  * In ascending order of priority:
+    * Logical: `and`, `or` (right to left)
+    * Equality: `==`, `!=`, `<>` (left to right)
+    * Comparison: `>`, `>=`, `<`, `<=`, `contains` (left to right)
+  - For example, this is now supported
+    * `{{ a > b == c < d or e == f }}` which is equivalent to
+    * `{{ ((a > b) == (c < d)) or (e == f) }}`
+- (TODO) Add support for parenthesized expressions
+  * e.g. `(a or b) and c`
+
+### Breaking changes
+* The Environment's `error_mode` option has been removed.
+  * `:warn` is no longer supported
+  * `:lax` and `lax_parse` is no longer supported
+  * `:strict` and `strict_parse` is no longer supported
+  * `strict2_parse` is renamed to `parse_markup`
+* The `warnings` system has been removed.
+
+### Migrating from `^5.11.0`
+- In custom tags that include `ParserSwitching`, rename `strict2_parse` to `parse_markup`
+- Remove code depending on `:error_mode`
+
 ## 5.14.0
 
 * Avoid materializing integer ranges in `for` and `tablerow` loops, and account for each visited range item [Ian Ker-Seymer]

README.md

@@ -93,31 +93,6 @@ LIQUID
 
 By using Environments, you ensure that custom tags and filters are only available in the contexts where they are needed, making your Liquid templates more robust and easier to manage. For smaller projects, a global environment is available via `Liquid::Environment.default`.
 
-### Error Modes
-
-Setting the error mode of Liquid lets you specify how strictly you want your templates to be interpreted.
-Normally the parser is very lax and will accept almost anything without error. Unfortunately this can make
-it very hard to debug and can lead to unexpected behaviour.
-
-Liquid also comes with different parsers that can be used when editing templates to give better error messages
-when templates are invalid. You can enable this new parser like this:
-
-```ruby
-Liquid::Environment.default.error_mode = :strict2 # Raises a SyntaxError when invalid syntax is used in all tags
-Liquid::Environment.default.error_mode = :strict  # Raises a SyntaxError when invalid syntax is used in some tags
-Liquid::Environment.default.error_mode = :warn    # Adds strict errors to template.errors but continues as normal
-Liquid::Environment.default.error_mode = :lax     # The default mode, accepts almost anything.
-```
-
-If you want to set the error mode only on specific templates you can pass `:error_mode` as an option to `parse`:
-```ruby
-Liquid::Template.parse(source, error_mode: :strict)
-```
-This is useful for doing things like enabling strict mode only in the theme editor.
-
-It is recommended that you enable `:strict` or `:warn` mode on new apps to stop invalid templates from being created.
-It is also recommended that you use it in the template editors of existing apps to give editors better error messages.
-
 ### Undefined variables and filters
 
 By default, the renderer doesn't raise or in any other way notify you if some variables or filters are missing, i.e. not passed to the `render` method.

Rakefile

@@ -33,29 +33,12 @@ task :rubocop do
   end
 end
 
-desc('runs test suite with lax, strict, and strict2 parsers')
+desc('runs test suite')
 task :test do
-  ENV['LIQUID_PARSER_MODE'] = 'lax'
-  Rake::Task['base_test'].invoke
-
-  ENV['LIQUID_PARSER_MODE'] = 'strict'
-  Rake::Task['base_test'].reenable
-  Rake::Task['base_test'].invoke
-
-  ENV['LIQUID_PARSER_MODE'] = 'strict2'
   Rake::Task['base_test'].reenable
   Rake::Task['base_test'].invoke
 
   if RUBY_ENGINE == 'ruby' || RUBY_ENGINE == 'truffleruby'
-    ENV['LIQUID_PARSER_MODE'] = 'lax'
-    Rake::Task['integration_test'].reenable
-    Rake::Task['integration_test'].invoke
-
-    ENV['LIQUID_PARSER_MODE'] = 'strict'
-    Rake::Task['integration_test'].reenable
-    Rake::Task['integration_test'].invoke
-
-    ENV['LIQUID_PARSER_MODE'] = 'strict2'
     Rake::Task['integration_test'].reenable
     Rake::Task['integration_test'].invoke
   end
@@ -78,24 +61,11 @@ task release: :build do
 end
 
 namespace :benchmark do
-  desc "Run the liquid benchmark with lax parsing"
-  task :lax do
-    ruby "./performance/benchmark.rb lax"
-  end
-
-  desc "Run the liquid benchmark with strict parsing"
-  task :strict do
-    ruby "./performance/benchmark.rb strict"
-  end
-
-  desc "Run the liquid benchmark with strict2 parsing"
-  task :strict2 do
-    ruby "./performance/benchmark.rb strict2"
+  desc "Run the liquid benchmark"
+  task :run do
+    ruby "./performance/benchmark.rb"
   end
 
-  desc "Run the liquid benchmark with lax, strict, and strict2 parsing"
-  task run: [:lax, :strict, :strict2]
-
   desc "Run unit benchmarks"
   namespace :unit do
     task :all do
@@ -126,11 +96,6 @@ namespace :profile do
   task :run do
     ruby "./performance/profile.rb"
   end
-
-  desc "Run the liquid profile/performance coverage with strict parsing"
-  task :strict do
-    ruby "./performance/profile.rb strict"
-  end
 end
 
 namespace :memory_profile do

lib/liquid/block_body.rb

@@ -86,24 +86,19 @@ def self.raise_missing_variable_terminator(token, parse_context)
     def self.render_node(context, output, node)
       node.render_to_output_buffer(context, output)
     rescue => exc
-      blank_tag = !node.instance_of?(Variable) && node.blank?
-      rescue_render_node(context, output, node.line_number, exc, blank_tag)
+      rescue_render_node(context, output, node.line_number, exc)
     end
 
     # @api private
-    def self.rescue_render_node(context, output, line_number, exc, blank_tag)
+    # The unused blank_tag argument keeps the liquid-c call signature compatible.
+    def self.rescue_render_node(context, output, line_number, exc, _blank_tag = false)
       case exc
       when MemoryError
         raise
       when UndefinedVariable, UndefinedDropMethod, UndefinedFilter
         context.handle_error(exc, line_number)
       else
-        error_message = context.handle_error(exc, line_number)
-        error_mode = context.registers.static[:template_error_mode]
-        suppress_error_text = blank_tag && error_mode != :strict2 && error_mode != :rigid
-        unless suppress_error_text # blank-tag suppression is kept for backwards compatibility outside strict2
-          output << error_message
-        end
+        output << context.handle_error(exc, line_number)
       end
     end
 

lib/liquid/context.rb

@@ -60,10 +60,6 @@ def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_erro
     end
     # rubocop:enable Metrics/ParameterLists
 
-    def warnings
-      @warnings ||= []
-    end
-
     def strainer
       @strainer ||= @environment.create_strainer(self, @filters)
     end
@@ -157,7 +153,6 @@ def new_isolated_subcontext
         subcontext.filters  = @filters
         subcontext.strainer = nil
         subcontext.errors   = errors
-        subcontext.warnings = warnings
         subcontext.disabled_tags = @disabled_tags
       end
     end
@@ -262,7 +257,7 @@ def tag_disabled?(tag_name)
 
     protected
 
-    attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters, :disabled_tags
+    attr_writer :base_scope_depth, :errors, :strainer, :filters, :disabled_tags
 
     private
 

lib/liquid/environment.rb

@@ -4,10 +4,6 @@ module Liquid
   # The Environment is the container for all configuration options of Liquid, such as
   # the registered tags, filters, and the default error mode.
   class Environment
-    # The default error mode for all templates. This can be overridden on a
-    # per-template basis.
-    attr_accessor :error_mode
-
     # The tags that are available to use in the template.
     attr_accessor :tags
 
@@ -33,17 +29,14 @@ class << self
       #  the template.
       # @param file_system The default file system that is used
       #  to load templates from.
-      # @param error_mode [Symbol] The default error mode for all templates
-      #  (either :strict2, :strict, :warn, or :lax).
       # @param exception_renderer [Proc] The exception renderer that is used to
       #   render exceptions.
       # @yieldparam environment [Environment] The environment instance that is being built.
       # @return [Environment] The new environment instance.
-      def build(tags: nil, file_system: nil, error_mode: nil, exception_renderer: nil)
+      def build(tags: nil, file_system: nil, exception_renderer: nil)
         ret = new
         ret.tags = tags if tags
         ret.file_system = file_system if file_system
-        ret.error_mode = error_mode if error_mode
         ret.exception_renderer = exception_renderer if exception_renderer
         yield ret if block_given?
         ret.freeze
@@ -75,7 +68,6 @@ def dangerously_override(environment)
     # @api private
     def initialize
       @tags = Tags::STANDARD_TAGS.dup
-      @error_mode = :lax
       @strainer_template = Class.new(StrainerTemplate).tap do |klass|
         klass.add_filter(StandardFilters)
       end

lib/liquid/expression.rb

@@ -13,9 +13,6 @@ class Expression
       'false' => false,
       'blank' => '',
       'empty' => '',
-      # in lax mode, minus sign can be a VariableLookup
-      # For simplicity and performace, we treat it like a literal
-      '-' => VariableLookup.parse("-", nil).freeze,
     }.freeze
 
     DOT = ".".ord

lib/liquid/parse_context.rb

@@ -3,14 +3,13 @@
 module Liquid
   class ParseContext
     attr_accessor :locale, :line_number, :trim_whitespace, :depth
-    attr_reader :partial, :warnings, :error_mode, :environment
+    attr_reader :partial, :environment
 
     def initialize(options = Const::EMPTY_HASH)
       @environment = options.fetch(:environment, Environment.default)
       @template_options = options ? options.dup : {}
 
-      @locale   = @template_options[:locale] ||= I18n.new
-      @warnings = []
+      @locale = @template_options[:locale] ||= I18n.new
 
       # constructing new StringScanner in Lexer, Tokenizer, etc is expensive
       # This StringScanner will be shared by all of them
@@ -38,7 +37,7 @@ def new_block_body
 
     def new_parser(input)
       @string_scanner.string = input
-      Parser.new(@string_scanner, reject_bare_brackets: @error_mode == :strict2 || @error_mode == :rigid)
+      Parser.new(@string_scanner, reject_bare_brackets: true)
     end
 
     def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
@@ -55,25 +54,19 @@ def safe_parse_expression(parser)
     end
 
     def parse_expression(markup, safe: false)
-      if !safe && @error_mode == :strict2
-        # parse_expression is a widely used API. To maintain backward
-        # compatibility while raising awareness about strict2 parser standards,
-        # the safe flag supports API users make a deliberate decision.
-        #
-        # In strict2 mode, markup MUST come from a string returned by the parser
-        # (e.g., parser.expression). We're not calling the parser here to
-        # prevent redundant parser overhead.
-        raise Liquid::InternalError, "unsafe parse_expression cannot be used in strict2 mode"
-      end
+      # markup MUST come from a string returned by the parser
+      # (e.g., parser.expression). We're not calling the parser here to
+      # prevent redundant parser overhead. The `safe` opt-in
+      # exists to ensure it is not accidentally still called with
+      # the result of a regex.
+      raise Liquid::InternalError, "unsafe parse_expression cannot be used" unless safe
 
       Expression.parse(markup, @string_scanner, @expression_cache)
     end
 
     def partial=(value)
       @partial = value
       @options = value ? partial_options : @template_options
-
-      @error_mode = @options[:error_mode] || @environment.error_mode
     end
 
     def partial_options

lib/liquid/parser_switching.rb

@@ -2,74 +2,15 @@
 
 module Liquid
   module ParserSwitching
-    # Do not use this.
-    #
-    # It's basically doing the same thing the {#parse_with_selected_parser},
-    # except this will try the strict parser regardless of the error mode,
-    # and fall back to the lax parser if the error mode is lax or warn,
-    # except when in strict2 mode where it uses the strict2 parser.
-    #
-    # @deprecated Use {#parse_with_selected_parser} instead.
-    def strict_parse_with_error_mode_fallback(markup)
-      return strict2_parse_with_error_context(markup) if strict2_mode?
-
-      strict_parse_with_error_context(markup)
-    rescue SyntaxError => e
-      case parse_context.error_mode
-      when :rigid
-        rigid_warn
-        raise
-      when :strict2
-        raise
-      when :strict
-        raise
-      when :warn
-        parse_context.warnings << e
-      end
-      lax_parse(markup)
-    end
-
     def parse_with_selected_parser(markup)
-      case parse_context.error_mode
-      when :rigid   then rigid_warn && strict2_parse_with_error_context(markup)
-      when :strict2 then strict2_parse_with_error_context(markup)
-      when :strict  then strict_parse_with_error_context(markup)
-      when :lax     then lax_parse(markup)
-      when :warn
-        begin
-          strict2_parse_with_error_context(markup)
-        rescue SyntaxError => e
-          parse_context.warnings << e
-          lax_parse(markup)
-        end
-      end
-    end
-
-    def strict2_mode?
-      parse_context.error_mode == :strict2 || parse_context.error_mode == :rigid
-    end
-
-    private
-
-    def rigid_warn
-      Deprecations.warn(':rigid', ':strict2')
-    end
-
-    def strict2_parse_with_error_context(markup)
-      strict2_parse(markup)
+      parse_markup(markup)
     rescue SyntaxError => e
       e.line_number    = line_number
       e.markup_context = markup_context(markup)
       raise e
     end
 
-    def strict_parse_with_error_context(markup)
-      strict_parse(markup)
-    rescue SyntaxError => e
-      e.line_number    = line_number
-      e.markup_context = markup_context(markup)
-      raise e
-    end
+    private
 
     def markup_context(markup)
       "in \"#{markup.strip}\""

lib/liquid/partial_cache.rb

@@ -4,7 +4,7 @@ module Liquid
   class PartialCache
     def self.load(template_name, context:, parse_context:)
       cached_partials = context.registers[:cached_partials]
-      cache_key = "#{template_name}:#{parse_context.error_mode}"
+      cache_key = template_name.to_s
       cached = cached_partials[cache_key]
       return cached if cached