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25 Commits

Author SHA1 Message Date
Dylan Thacker-Smith
f0cc366cfc Fix missing freeze for array of static environments 2020-09-30 10:26:14 -04:00
Dylan Thacker-Smith
efef03d944 Merge pull request #1294 from Shopify/changes-for-liquid-c-vm-variable
Refactor to support liquid-c VM compilation of variables
2020-09-29 21:02:26 -04:00
Dylan Thacker-Smith
33760f083a Extract rescue code from BlockBody#render_node for re-use in liquid-c 2020-09-25 11:24:39 -04:00
Dylan Thacker-Smith
013802c877 Move some unit tests without internal coupling to integration tests
since I would like to continue supporting these tests in liquid-c
in the foreseeable future.
2020-09-25 11:24:39 -04:00
Dylan Thacker-Smith
3dcad3b3cd Move test/integration/parse_tree_visitor_test.rb to test/unit
The ParseTreeVisitor exposes the liquid internals that won't be
kept compatible with liquid-c, so move it out of the integration
tests directory so that we can easily ignore it when testing liquid-c
2020-09-25 11:24:39 -04:00
Dylan Thacker-Smith
db065315ba Allow creating symbols that are garbage collected in a test 2020-09-25 11:24:39 -04:00
Dylan Thacker-Smith
a03f02789b Only use MethodLiteral in condition expressions (#1300) 2020-09-25 11:10:33 -04:00
Dylan Thacker-Smith
ca4b9b43af Port liquid-c bug compatible whitespace trimming (#1291) 2020-09-16 16:07:36 -04:00
Dylan Thacker-Smith
77084930e9 Bring back silencing of errors in blank nodes for backwards compatibility (#1292) 2020-09-15 10:35:18 -04:00
Dylan Thacker-Smith
fb77921b15 Merge pull request #1290 from Shopify/document-unknown-tag-refactor
Pass the tag markup and tokenizer to Document#unknown_tag
2020-09-11 09:34:16 -04:00
Dylan Thacker-Smith
0d02dea20b Rename Liquid::Block#unknown_tag parameters for clarity 2020-09-11 09:33:12 -04:00
Dylan Thacker-Smith
86b47ba28b Pass the tag markup and tokenizer to Document#unknown_tag
The parse_context no longer needs to be passed in because it is available
through through an attr_reader on the instance. However, the markup and
tokenizer weren't made available.  This refactor also makes the parameters
given to Document#unknown_tag consistent with Block#unknown_tag.
2020-09-11 09:33:12 -04:00
Dylan Thacker-Smith
95ff0595c6 Merge pull request #1289 from Shopify/refactor-for-c-block-body
Avoid direct coupling to BlockBody instances for liquid-c replacement
2020-09-11 09:15:58 -04:00
Dylan Thacker-Smith
bbc56f35ec Add ParseContext#new_block_body to centralize the liquid-c override point 2020-09-09 12:25:35 -04:00
Dylan Thacker-Smith
dfbbf87ba9 Use BlockBody from Document using composition rather than inheritence
This way liquid-c can more cleanly use a Liquid::C::BlockBody object
for the block body by overriding Liquid::Document#new_body.
2020-09-08 14:00:52 -04:00
Dylan Thacker-Smith
037b603603 Turn some Liquid::BlockBody methods into class methods for liquid-c
So they can be used from a Liquid::C::BlockBody
2020-09-08 14:00:48 -04:00
Dylan Thacker-Smith
bd33df09de Provide Block#new_body so that liquid-c can override it
This way liquid-c can return a body of a different class that wraps
a C implementation.
2020-09-08 13:59:48 -04:00
Dylan Thacker-Smith
6ca5b62112 Merge pull request #1285 from Shopify/fix-render-length-resource-limit
Fix render length resource limit so it doesn't multiply nested output
2020-09-08 13:57:30 -04:00
Dylan Thacker-Smith
e1a2057a1b Update assign_score during capturing
To stop long captures before they grow the heap more then they should.
2020-09-03 11:13:08 -04:00
Dylan Thacker-Smith
ae9dbe0ca7 Fix render length resource limit so it doesn't multiply nested output 2020-09-03 11:13:04 -04:00
Dylan Thacker-Smith
3b486425b0 Handle BlockBody#blank? at parse time (#1287) 2020-09-03 11:07:13 -04:00
Dylan Thacker-Smith
b08bcf00ac Push interrupts from Continue and Break tags rather than from BlockBody (#1286) 2020-09-03 06:55:24 -04:00
Dylan Thacker-Smith
0740e8b431 Remove unused quirk allowing liquid tags to close a block it is nested in (#1284) 2020-09-03 06:51:56 -04:00
Dylan Thacker-Smith
5532df880f Handle disabled tags errors like other liquid errors (#1275) 2020-08-18 11:39:54 -04:00
Dylan Thacker-Smith
2b11efc3ae Fix performance regression from introduction of Template#disable_tags (#1274) 2020-08-18 11:25:51 -04:00
40 changed files with 599 additions and 422 deletions

View File

@@ -63,6 +63,8 @@ require 'liquid/expression'
require 'liquid/context'
require 'liquid/parser_switching'
require 'liquid/tag'
require 'liquid/tag/disabler'
require 'liquid/tag/disableable'
require 'liquid/block'
require 'liquid/block_body'
require 'liquid/document'
@@ -86,4 +88,3 @@ require 'liquid/template_factory'
# Load all the tags of the standard library
#
Dir["#{__dir__}/liquid/tags/*.rb"].each { |f| require f }
Dir["#{__dir__}/liquid/registers/*.rb"].each { |f| require f }

View File

@@ -10,7 +10,7 @@ module Liquid
end
def parse(tokens)
@body = BlockBody.new
@body = new_body
while parse_body(@body, tokens)
end
end
@@ -28,7 +28,12 @@ module Liquid
@body.nodelist
end
def unknown_tag(tag, _params, _tokens)
def unknown_tag(tag_name, _markup, _tokenizer)
Block.raise_unknown_tag(tag_name, block_name, block_delimiter, parse_context)
end
# @api private
def self.raise_unknown_tag(tag, block_name, block_delimiter, parse_context)
if tag == 'else'
raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_else",
block_name: block_name)
@@ -50,8 +55,14 @@ module Liquid
@block_delimiter ||= "end#{block_name}"
end
protected
private
# @api public
def new_body
parse_context.new_block_body
end
# @api public
def parse_body(body, tokens)
if parse_context.depth >= MAX_DEPTH
raise StackLevelError, "Nesting too deep"

View File

@@ -54,28 +54,60 @@ module Liquid
end
# @api private
def self.unknown_tag_in_liquid_tag(end_tag_name, end_tag_markup)
yield end_tag_name, end_tag_markup
ensure
Usage.increment("liquid_tag_contains_outer_tag") unless $ERROR_INFO.is_a?(SyntaxError)
def self.unknown_tag_in_liquid_tag(tag, parse_context)
Block.raise_unknown_tag(tag, 'liquid', '%}', parse_context)
end
private def parse_liquid_tag(markup, parse_context, &block)
liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
parse_for_liquid_tag(liquid_tag_tokenizer, parse_context) do |end_tag_name, end_tag_markup|
next unless end_tag_name
self.class.unknown_tag_in_liquid_tag(end_tag_name, end_tag_markup, &block)
# @api private
def self.raise_missing_tag_terminator(token, parse_context)
raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
end
# @api private
def self.raise_missing_variable_terminator(token, parse_context)
raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
end
# @api private
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)
end
# @api private
def self.rescue_render_node(context, output, line_number, exc, blank_tag)
case exc
when MemoryError
raise
when UndefinedVariable, UndefinedDropMethod, UndefinedFilter
context.handle_error(exc, line_number)
else
error_message = context.handle_error(exc, line_number)
unless blank_tag # conditional for backwards compatibility
output << error_message
end
end
end
private def parse_for_document(tokenizer, parse_context, &block)
private def parse_liquid_tag(markup, parse_context)
liquid_tag_tokenizer = Tokenizer.new(markup, line_number: parse_context.line_number, for_liquid_tag: true)
parse_for_liquid_tag(liquid_tag_tokenizer, parse_context) do |end_tag_name, _end_tag_markup|
if end_tag_name
BlockBody.unknown_tag_in_liquid_tag(end_tag_name, parse_context)
end
end
end
private def parse_for_document(tokenizer, parse_context)
while (token = tokenizer.shift)
next if token.empty?
case
when token.start_with?(TAGSTART)
whitespace_handler(token, parse_context)
unless token =~ FullToken
raise_missing_tag_terminator(token, parse_context)
BlockBody.raise_missing_tag_terminator(token, parse_context)
end
tag_name = Regexp.last_match(2)
markup = Regexp.last_match(4)
@@ -87,7 +119,7 @@ module Liquid
end
if tag_name == 'liquid'
parse_liquid_tag(markup, parse_context, &block)
parse_liquid_tag(markup, parse_context)
next
end
@@ -121,7 +153,11 @@ module Liquid
if token[2] == WhitespaceControl
previous_token = @nodelist.last
if previous_token.is_a?(String)
first_byte = previous_token.getbyte(0)
previous_token.rstrip!
if previous_token.empty? && parse_context[:bug_compatible_whitespace_trimming] && first_byte
previous_token << first_byte
end
end
end
parse_context.trim_whitespace = (token[-3] == WhitespaceControl)
@@ -131,38 +167,47 @@ module Liquid
@blank
end
# Remove blank strings in the block body for a control flow tag (e.g. `if`, `for`, `case`, `unless`)
# with a blank body.
#
# For example, in a conditional assignment like the following
#
# ```
# {% if size > max_size %}
# {% assign size = max_size %}
# {% endif %}
# ```
#
# we assume the intention wasn't to output the blank spaces in the `if` tag's block body, so this method
# will remove them to reduce the render output size.
#
# Note that it is now preferred to use the `liquid` tag for this use case.
def remove_blank_strings
raise "remove_blank_strings only support being called on a blank block body" unless @blank
@nodelist.reject! { |node| node.instance_of?(String) }
end
def render(context)
render_to_output_buffer(context, +'')
end
def render_to_output_buffer(context, output)
context.resource_limits.render_score += @nodelist.length
context.resource_limits.increment_render_score(@nodelist.length)
idx = 0
while (node = @nodelist[idx])
previous_output_size = output.bytesize
case node
when String
if node.instance_of?(String)
output << node
when Variable
else
render_node(context, output, node)
when Block
render_node(context, node.blank? ? +'' : output, node)
break if context.interrupt? # might have happened in a for-block
when Continue, Break
# If we get an Interrupt that means the block must stop processing. An
# Interrupt is any command that stops block execution such as {% break %}
# or {% continue %}
context.push_interrupt(node.interrupt)
break
else # Other non-Block tags
render_node(context, output, node)
break if context.interrupt? # might have happened through an include
# or {% continue %}. These tags may also occur through Block or Include tags.
break if context.interrupt? # might have happened in a for-block
end
idx += 1
raise_if_resource_limits_reached(context, output.bytesize - previous_output_size)
context.resource_limits.increment_write_score(output)
end
output
@@ -171,29 +216,7 @@ module Liquid
private
def render_node(context, output, node)
if node.disabled?(context)
output << node.disabled_error_message
return
end
disable_tags(context, node.disabled_tags) do
node.render_to_output_buffer(context, output)
end
rescue UndefinedVariable, UndefinedDropMethod, UndefinedFilter => e
context.handle_error(e, node.line_number)
rescue ::StandardError => e
line_number = node.is_a?(String) ? nil : node.line_number
output << context.handle_error(e, line_number)
end
def disable_tags(context, tags, &block)
return yield if tags.empty?
context.registers[:disabled_tags].disable(tags, &block)
end
def raise_if_resource_limits_reached(context, length)
context.resource_limits.render_length += length
return unless context.resource_limits.reached?
raise MemoryError, "Memory limits exceeded"
BlockBody.render_node(context, output, node)
end
def create_variable(token, parse_context)
@@ -201,15 +224,17 @@ module Liquid
markup = content.first
return Variable.new(markup, parse_context)
end
raise_missing_variable_terminator(token, parse_context)
BlockBody.raise_missing_variable_terminator(token, parse_context)
end
# @deprecated Use {.raise_missing_tag_terminator} instead
def raise_missing_tag_terminator(token, parse_context)
raise SyntaxError, parse_context.locale.t("errors.syntax.tag_termination", token: token, tag_end: TagEnd.inspect)
BlockBody.raise_missing_tag_terminator(token, parse_context)
end
# @deprecated Use {.raise_missing_variable_terminator} instead
def raise_missing_variable_terminator(token, parse_context)
raise SyntaxError, parse_context.locale.t("errors.syntax.variable_termination", token: token, tag_end: VariableEnd.inspect)
BlockBody.raise_missing_variable_terminator(token, parse_context)
end
def registered_tags

View File

@@ -27,10 +27,28 @@ module Liquid
end,
}
class MethodLiteral
attr_reader :method_name, :to_s
def initialize(method_name, to_s)
@method_name = method_name
@to_s = to_s
end
end
@@method_literals = {
'blank' => MethodLiteral.new(:blank?, '').freeze,
'empty' => MethodLiteral.new(:empty?, '').freeze,
}
def self.operators
@@operators
end
def self.parse_expression(markup)
@@method_literals[markup] || Expression.parse(markup)
end
attr_reader :attachment, :child_condition
attr_accessor :left, :operator, :right
@@ -91,7 +109,7 @@ module Liquid
private
def equal_variables(left, right)
if left.is_a?(Liquid::Expression::MethodLiteral)
if left.is_a?(MethodLiteral)
if right.respond_to?(left.method_name)
return right.send(left.method_name)
else
@@ -99,7 +117,7 @@ module Liquid
end
end
if right.is_a?(Liquid::Expression::MethodLiteral)
if right.is_a?(MethodLiteral)
if left.respond_to?(right.method_name)
return left.send(right.method_name)
else

View File

@@ -18,15 +18,16 @@ module Liquid
attr_accessor :exception_renderer, :template_name, :partial, :global_filter, :strict_variables, :strict_filters
# rubocop:disable Metrics/ParameterLists
def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: {})
def self.build(environments: {}, outer_scope: {}, registers: {}, rethrow_errors: false, resource_limits: nil, static_environments: [])
new(environments, outer_scope, registers, rethrow_errors, resource_limits, static_environments)
end
def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = {})
def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil, static_environments = [])
@environments = [environments]
@environments.flatten!
@static_environments = [static_environments].flat_map(&:freeze).freeze
static_environments = [static_environments] if static_environments.is_a?(Hash)
@static_environments = static_environments.map(&:freeze).freeze
@scopes = [(outer_scope || {})]
@registers = registers
@errors = []
@@ -44,6 +45,7 @@ module Liquid
@interrupts = []
@filters = []
@global_filter = nil
@disabled_tags = {}
end
# rubocop:enable Metrics/ParameterLists
@@ -144,6 +146,7 @@ module Liquid
subcontext.strainer = nil
subcontext.errors = errors
subcontext.warnings = warnings
subcontext.disabled_tags = @disabled_tags
end
end
@@ -208,9 +211,24 @@ module Liquid
end
end
def with_disabled_tags(tag_names)
tag_names.each do |name|
@disabled_tags[name] = @disabled_tags.fetch(name, 0) + 1
end
yield
ensure
tag_names.each do |name|
@disabled_tags[name] -= 1
end
end
def tag_disabled?(tag_name)
@disabled_tags.fetch(tag_name, 0) > 0
end
protected
attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters
attr_writer :base_scope_depth, :warnings, :errors, :strainer, :filters, :disabled_tags
private

View File

@@ -1,23 +1,33 @@
# frozen_string_literal: true
module Liquid
class Document < BlockBody
class Document
def self.parse(tokens, parse_context)
doc = new
doc = new(parse_context)
doc.parse(tokens, parse_context)
doc
end
def parse(tokens, parse_context)
super do |end_tag_name, _end_tag_params|
unknown_tag(end_tag_name, parse_context) if end_tag_name
attr_reader :parse_context, :body
def initialize(parse_context)
@parse_context = parse_context
@body = new_body
end
def nodelist
@body.nodelist
end
def parse(tokenizer, parse_context)
while parse_body(tokenizer)
end
rescue SyntaxError => e
e.line_number ||= parse_context.line_number
raise
end
def unknown_tag(tag, parse_context)
def unknown_tag(tag, _markup, _tokenizer)
case tag
when 'else', 'end'
raise SyntaxError, parse_context.locale.t("errors.syntax.unexpected_outer_tag", tag: tag)
@@ -25,5 +35,30 @@ module Liquid
raise SyntaxError, parse_context.locale.t("errors.syntax.unknown_tag", tag: tag)
end
end
def render_to_output_buffer(context, output)
@body.render_to_output_buffer(context, output)
end
def render(context)
@body.render(context)
end
private
def new_body
parse_context.new_block_body
end
def parse_body(tokenizer)
@body.parse(tokenizer, parse_context) do |unknown_tag_name, unknown_tag_markup|
if unknown_tag_name
unknown_tag(unknown_tag_name, unknown_tag_markup, tokenizer)
true
else
false
end
end
end
end
end

View File

@@ -53,5 +53,6 @@ module Liquid
UndefinedDropMethod = Class.new(Error)
UndefinedFilter = Class.new(Error)
MethodOverrideError = Class.new(Error)
DisabledError = Class.new(Error)
InternalError = Class.new(Error)
end

View File

@@ -2,25 +2,12 @@
module Liquid
class Expression
class MethodLiteral
attr_reader :method_name, :to_s
def initialize(method_name, to_s)
@method_name = method_name
@to_s = to_s
end
def to_liquid
to_s
end
end
LITERALS = {
nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
'true' => true,
'false' => false,
'blank' => MethodLiteral.new(:blank?, '').freeze,
'empty' => MethodLiteral.new(:empty?, '').freeze
'blank' => '',
'empty' => ''
}.freeze
SINGLE_QUOTED_STRING = /\A'(.*)'\z/m

View File

@@ -19,6 +19,10 @@ module Liquid
@options[option_key]
end
def new_block_body
Liquid::BlockBody.new
end
def partial=(value)
@partial = value
@options = value ? partial_options : @template_options

View File

@@ -1,25 +1,21 @@
# frozen_string_literal: true
module Liquid
class BlockBody
def render_node_with_profiling(context, output, node)
module BlockBodyProfilingHook
def render_node(context, output, node)
Profiler.profile_node_render(node) do
render_node_without_profiling(context, output, node)
super
end
end
alias_method :render_node_without_profiling, :render_node
alias_method :render_node, :render_node_with_profiling
end
BlockBody.prepend(BlockBodyProfilingHook)
class Include < Tag
def render_to_output_buffer_with_profiling(context, output)
module IncludeProfilingHook
def render_to_output_buffer(context, output)
Profiler.profile_children(context.evaluate(@template_name_expr).to_s) do
render_to_output_buffer_without_profiling(context, output)
super
end
end
alias_method :render_to_output_buffer_without_profiling, :render_to_output_buffer
alias_method :render_to_output_buffer, :render_to_output_buffer_with_profiling
end
Include.prepend(IncludeProfilingHook)
end

View File

@@ -1,32 +0,0 @@
# frozen_string_literal: true
module Liquid
class DisabledTags < Register
def initialize
@disabled_tags = {}
end
def disabled?(tag)
@disabled_tags.key?(tag) && @disabled_tags[tag] > 0
end
def disable(tags)
tags.each(&method(:increment))
yield
ensure
tags.each(&method(:decrement))
end
private
def increment(tag)
@disabled_tags[tag] ||= 0
@disabled_tags[tag] += 1
end
def decrement(tag)
@disabled_tags[tag] -= 1
end
end
Template.add_register(:disabled_tags, DisabledTags.new)
end

View File

@@ -2,8 +2,8 @@
module Liquid
class ResourceLimits
attr_accessor :render_length, :render_score, :assign_score,
:render_length_limit, :render_score_limit, :assign_score_limit
attr_accessor :render_length_limit, :render_score_limit, :assign_score_limit
attr_reader :render_score, :assign_score
def initialize(limits)
@render_length_limit = limits[:render_length_limit]
@@ -12,14 +12,51 @@ module Liquid
reset
end
def increment_render_score(amount)
@render_score += amount
raise_limits_reached if @render_score_limit && @render_score > @render_score_limit
end
def increment_assign_score(amount)
@assign_score += amount
raise_limits_reached if @assign_score_limit && @assign_score > @assign_score_limit
end
# update either render_length or assign_score based on whether or not the writes are captured
def increment_write_score(output)
if (last_captured = @last_capture_length)
captured = output.bytesize
increment = captured - last_captured
@last_capture_length = captured
increment_assign_score(increment)
elsif @render_length_limit && output.bytesize > @render_length_limit
raise_limits_reached
end
end
def raise_limits_reached
@reached_limit = true
raise MemoryError, "Memory limits exceeded"
end
def reached?
(@render_length_limit && @render_length > @render_length_limit) ||
(@render_score_limit && @render_score > @render_score_limit) ||
(@assign_score_limit && @assign_score > @assign_score_limit)
@reached_limit
end
def reset
@render_length = @render_score = @assign_score = 0
@reached_limit = false
@last_capture_length = nil
@render_score = @assign_score = 0
end
def with_capture
old_capture_length = @last_capture_length
begin
@last_capture_length = 0
yield
ensure
@last_capture_length = old_capture_length
end
end
end
end

View File

@@ -13,15 +13,13 @@ module Liquid
tag
end
def disable_tags(*tags)
disabled_tags.push(*tags)
def disable_tags(*tag_names)
@disabled_tags ||= []
@disabled_tags.concat(tag_names)
prepend(Disabler)
end
private :new
def disabled_tags
@disabled_tags ||= []
end
end
def initialize(tag_name, markup, parse_context)
@@ -46,14 +44,6 @@ module Liquid
''
end
def disabled?(context)
context.registers[:disabled_tags].disabled?(tag_name)
end
def disabled_error_message
"#{tag_name} #{options[:locale].t('errors.disabled.tag')}"
end
# For backwards compatibility with custom tags. In a future release, the semantics
# of the `render_to_output_buffer` method will become the default and the `render`
# method will be removed.
@@ -65,9 +55,5 @@ module Liquid
def blank?
false
end
def disabled_tags
self.class.disabled_tags
end
end
end

View File

@@ -0,0 +1,22 @@
# frozen_string_literal: true
module Liquid
class Tag
module Disableable
def render_to_output_buffer(context, output)
if context.tag_disabled?(tag_name)
output << disabled_error(context)
return
end
super
end
def disabled_error(context)
# raise then rescue the exception so that the Context#exception_renderer can re-raise it
raise DisabledError, "#{tag_name} #{parse_context[:locale].t('errors.disabled.tag')}"
rescue DisabledError => exc
context.handle_error(exc, line_number)
end
end
end
end

View File

@@ -0,0 +1,21 @@
# frozen_string_literal: true
module Liquid
class Tag
module Disabler
module ClassMethods
attr_reader :disabled_tags
end
def self.prepended(base)
base.extend(ClassMethods)
end
def render_to_output_buffer(context, output)
context.with_disabled_tags(self.class.disabled_tags) do
super
end
end
end
end
end

View File

@@ -27,7 +27,7 @@ module Liquid
def render_to_output_buffer(context, output)
val = @from.render(context)
context.scopes.last[@to] = val
context.resource_limits.assign_score += assign_score_of(val)
context.resource_limits.increment_assign_score(assign_score_of(val))
output
end

View File

@@ -11,8 +11,11 @@ module Liquid
# {% endfor %}
#
class Break < Tag
def interrupt
BreakInterrupt.new
INTERRUPT = BreakInterrupt.new.freeze
def render_to_output_buffer(context, output)
context.push_interrupt(INTERRUPT)
output
end
end

View File

@@ -25,10 +25,10 @@ module Liquid
end
def render_to_output_buffer(context, output)
previous_output_size = output.bytesize
super
context.scopes.last[@to] = output
context.resource_limits.assign_score += (output.bytesize - previous_output_size)
context.resource_limits.with_capture do
capture_output = render(context)
context.scopes.last[@to] = capture_output
end
output
end

View File

@@ -19,8 +19,11 @@ module Liquid
end
def parse(tokens)
body = BlockBody.new
body = new_body
body = @blocks.last.attachment while parse_body(body, tokens)
if blank?
@blocks.each { |condition| condition.attachment.remove_blank_strings }
end
end
def nodelist
@@ -56,7 +59,7 @@ module Liquid
private
def record_when_condition(markup)
body = BlockBody.new
body = new_body
while markup
unless markup =~ WhenSyntax
@@ -65,7 +68,7 @@ module Liquid
markup = Regexp.last_match(2)
block = Condition.new(@left, '==', Expression.parse(Regexp.last_match(1)))
block = Condition.new(@left, '==', Condition.parse_expression(Regexp.last_match(1)))
block.attach(body)
@blocks << block
end
@@ -77,7 +80,7 @@ module Liquid
end
block = ElseCondition.new
block.attach(BlockBody.new)
block.attach(new_body)
@blocks << block
end

View File

@@ -11,8 +11,11 @@ module Liquid
# {% endfor %}
#
class Continue < Tag
def interrupt
ContinueInterrupt.new
INTERRUPT = ContinueInterrupt.new.freeze
def render_to_output_buffer(context, output)
context.push_interrupt(INTERRUPT)
output
end
end

View File

@@ -54,13 +54,18 @@ module Liquid
super
@from = @limit = nil
parse_with_selected_parser(markup)
@for_block = BlockBody.new
@for_block = new_body
@else_block = nil
end
def parse(tokens)
return unless parse_body(@for_block, tokens)
parse_body(@else_block, tokens)
if parse_body(@for_block, tokens)
parse_body(@else_block, tokens)
end
if blank?
@for_block.remove_blank_strings
@else_block&.remove_blank_strings
end
end
def nodelist
@@ -69,7 +74,7 @@ module Liquid
def unknown_tag(tag, markup, tokens)
return super unless tag == 'else'
@else_block = BlockBody.new
@else_block = new_body
end
def render_to_output_buffer(context, output)

View File

@@ -31,6 +31,9 @@ module Liquid
def parse(tokens)
while parse_body(@blocks.last.attachment, tokens)
end
if blank?
@blocks.each { |condition| condition.attachment.remove_blank_strings }
end
end
def unknown_tag(tag, markup, tokens)
@@ -61,21 +64,25 @@ module Liquid
end
@blocks.push(block)
block.attach(BlockBody.new)
block.attach(new_body)
end
def parse_expression(markup)
Condition.parse_expression(markup)
end
def lax_parse(markup)
expressions = markup.scan(ExpressionsAndOperators)
raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop =~ Syntax
condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
until expressions.empty?
operator = expressions.pop.to_s.strip
raise SyntaxError, options[:locale].t("errors.syntax.if") unless expressions.pop.to_s =~ Syntax
new_condition = Condition.new(Expression.parse(Regexp.last_match(1)), Regexp.last_match(2), Expression.parse(Regexp.last_match(3)))
new_condition = Condition.new(parse_expression(Regexp.last_match(1)), Regexp.last_match(2), parse_expression(Regexp.last_match(3)))
raise SyntaxError, options[:locale].t("errors.syntax.if") unless BOOLEAN_OPERATORS.include?(operator)
new_condition.send(operator, condition)
condition = new_condition
@@ -103,9 +110,9 @@ module Liquid
end
def parse_comparison(p)
a = Expression.parse(p.expression)
a = parse_expression(p.expression)
if (op = p.consume?(:comparison))
b = Expression.parse(p.expression)
b = parse_expression(p.expression)
Condition.new(a, op, b)
else
Condition.new(a)

View File

@@ -16,6 +16,8 @@ module Liquid
# {% include 'product' for products %}
#
class Include < Tag
prepend Tag::Disableable
SYNTAX = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?(\s+(?:as)\s+(#{VariableSegment}+))?/o
Syntax = SYNTAX

View File

@@ -80,14 +80,6 @@ module Liquid
tags[name.to_s] = klass
end
attr_accessor :registers
Template.registers = {}
private :registers=
def add_register(name, klass)
registers[name.to_sym] = klass
end
# Pass a module with filter methods which should be available
# to all liquid views. Good for registering the standard library
def register_filter(mod)
@@ -194,10 +186,6 @@ module Liquid
context.add_filters(args.pop)
end
Template.registers.each do |key, register|
context_register[key] = register unless context_register.key?(key)
end
# Retrying a render resets resource usage
context.resource_limits.reset

View File

@@ -11,4 +11,48 @@ class BlockTest < Minitest::Test
end
assert_equal(exc.message, "Liquid syntax error: 'endunless' is not a valid delimiter for if tags. use endif")
end
def test_with_custom_tag
with_custom_tag('testtag', Block) do
assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
end
end
def test_custom_block_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
klass1 = Class.new(Block) do
def render(*)
'hello'
end
end
with_custom_tag('blabla', klass1) do
template = Liquid::Template.parse("{% blabla %} bla {% endblabla %}")
assert_equal 'hello', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'hello', output
assert_equal 'hello', buf
assert_equal buf.object_id, output.object_id
end
klass2 = Class.new(klass1) do
def render(*)
'foo' + super + 'bar'
end
end
with_custom_tag('blabla', klass2) do
template = Liquid::Template.parse("{% blabla %} foo {% endblabla %}")
assert_equal 'foohellobar', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'foohellobar', output
assert_equal 'foohellobar', buf
assert_equal buf.object_id, output.object_id
end
end
end

View File

@@ -65,7 +65,7 @@ class ArrayLike
end
end
class ContextUnitTest < Minitest::Test
class ContextTest < Minitest::Test
include Liquid
def setup
@@ -492,6 +492,17 @@ class ContextUnitTest < Minitest::Test
assert_equal('static', context['unshadowed'])
end
def test_static_environments_are_frozen
context = Context.build(
static_environments: [{
'lazy' => -> { 1 }
}],
)
assert_raises(FrozenError) do
context['lazy']
end
end
def test_apply_global_filter_when_no_global_filter_exist
context = Context.new
assert_equal('hi', context.apply_global_filter('hi'))
@@ -563,6 +574,35 @@ class ContextUnitTest < Minitest::Test
assert_equal('my filter result', template.render(subcontext))
end
def test_disables_tag_specified
context = Context.new
context.with_disabled_tags(%w(foo bar)) do
assert_equal true, context.tag_disabled?("foo")
assert_equal true, context.tag_disabled?("bar")
assert_equal false, context.tag_disabled?("unknown")
end
end
def test_disables_nested_tags
context = Context.new
context.with_disabled_tags(["foo"]) do
context.with_disabled_tags(["foo"]) do
assert_equal true, context.tag_disabled?("foo")
assert_equal false, context.tag_disabled?("bar")
end
context.with_disabled_tags(["bar"]) do
assert_equal true, context.tag_disabled?("foo")
assert_equal true, context.tag_disabled?("bar")
context.with_disabled_tags(["foo"]) do
assert_equal true, context.tag_disabled?("foo")
assert_equal true, context.tag_disabled?("bar")
end
end
assert_equal true, context.tag_disabled?("foo")
assert_equal false, context.tag_disabled?("bar")
end
end
private
def assert_no_object_allocations

View File

@@ -261,4 +261,12 @@ class ErrorHandlingTest < Minitest::Test
assert_equal("Argument error:\nLiquid error (product line 1): argument error", page)
assert_equal("product", template.errors.first.template_name)
end
def test_bug_compatible_silencing_of_errors_in_blank_nodes
output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}not blank{% assign x = 3 %}{% endif %}{{ x }}").render
assert_equal("Liquid error: comparison of Integer with String failed0", output)
output = Liquid::Template.parse("{% assign x = 0 %}{% if 1 < '2' %}{% assign x = 3 %}{% endif %}{{ x }}").render
assert_equal("0", output)
end
end

View File

@@ -1,27 +0,0 @@
# frozen_string_literal: true
require 'test_helper'
class DisabledTagsTest < Minitest::Test
include Liquid
class DisableRaw < Block
disable_tags "raw"
end
class DisableRawEcho < Block
disable_tags "raw", "echo"
end
def test_disables_raw
with_custom_tag('disable', DisableRaw) do
assert_template_result 'raw usage is not allowed in this contextfoo', '{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}'
end
end
def test_disables_echo_and_raw
with_custom_tag('disable', DisableRawEcho) do
assert_template_result 'raw usage is not allowed in this contextecho usage is not allowed in this context', '{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}'
end
end
end

View File

@@ -43,15 +43,22 @@ class SecurityTest < Minitest::Test
assert_equal(expected, Template.parse(text).render!(@assigns, filters: SecurityFilter))
end
def test_does_not_add_filters_to_symbol_table
def test_does_not_permanently_add_filters_to_symbol_table
current_symbols = Symbol.all_symbols
test = %( {{ "some_string" | a_bad_filter }} )
# MRI imprecisely marks objects found on the C stack, which can result
# in uninitialized memory being marked. This can even result in the test failing
# deterministically for a given compilation of ruby. Using a separate thread will
# keep these writes of the symbol pointer on a separate stack that will be garbage
# collected after Thread#join.
Thread.new do
test = %( {{ "some_string" | a_bad_filter }} )
Template.parse(test).render!
nil
end.join
template = Template.parse(test)
assert_equal([], (Symbol.all_symbols - current_symbols))
GC.start
template.render!
assert_equal([], (Symbol.all_symbols - current_symbols))
end

View File

@@ -0,0 +1,51 @@
# frozen_string_literal: true
require 'test_helper'
class TagDisableableTest < Minitest::Test
include Liquid
class DisableRaw < Block
disable_tags "raw"
end
class DisableRawEcho < Block
disable_tags "raw", "echo"
end
class DisableableRaw < Liquid::Raw
prepend Liquid::Tag::Disableable
end
class DisableableEcho < Liquid::Echo
prepend Liquid::Tag::Disableable
end
def test_disables_raw
with_disableable_tags do
with_custom_tag('disable', DisableRaw) do
output = Template.parse('{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}').render
assert_equal('Liquid error: raw usage is not allowed in this contextfoo', output)
end
end
end
def test_disables_echo_and_raw
with_disableable_tags do
with_custom_tag('disable', DisableRawEcho) do
output = Template.parse('{% disable %}{% raw %}Foobar{% endraw %}{% echo "foo" %}{% enddisable %}').render
assert_equal('Liquid error: raw usage is not allowed in this contextLiquid error: echo usage is not allowed in this context', output)
end
end
end
private
def with_disableable_tags
with_custom_tag('raw', DisableableRaw) do
with_custom_tag('echo', DisableableEcho) do
yield
end
end
end
end

View File

@@ -0,0 +1,45 @@
# frozen_string_literal: true
require 'test_helper'
class TagTest < Minitest::Test
include Liquid
def test_custom_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
klass1 = Class.new(Tag) do
def render(*)
'hello'
end
end
with_custom_tag('blabla', klass1) do
template = Liquid::Template.parse("{% blabla %}")
assert_equal 'hello', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'hello', output
assert_equal 'hello', buf
assert_equal buf.object_id, output.object_id
end
klass2 = Class.new(klass1) do
def render(*)
'foo' + super + 'bar'
end
end
with_custom_tag('blabla', klass2) do
template = Liquid::Template.parse("{% blabla %}")
assert_equal 'foohellobar', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'foohellobar', output
assert_equal 'foohellobar', buf
assert_equal buf.object_id, output.object_id
end
end
end

View File

@@ -82,15 +82,13 @@ class LiquidTagTest < Minitest::Test
end
def test_nested_liquid_tag
assert_usage_increment("liquid_tag_contains_outer_tag", times: 0) do
assert_template_result('good', <<~LIQUID)
{%- if true %}
{%- liquid
echo "good"
%}
{%- endif -%}
LIQUID
end
assert_template_result('good', <<~LIQUID)
{%- if true %}
{%- liquid
echo "good"
%}
{%- endif -%}
LIQUID
end
def test_cannot_open_blocks_living_past_a_liquid_tag
@@ -102,14 +100,12 @@ class LiquidTagTest < Minitest::Test
LIQUID
end
def test_quirk_can_close_blocks_created_before_a_liquid_tag
assert_usage_increment("liquid_tag_contains_outer_tag") do
assert_template_result("42", <<~LIQUID)
{%- if true -%}
42
{%- liquid endif -%}
LIQUID
end
def test_cannot_close_blocks_created_before_a_liquid_tag
assert_match_syntax_error("syntax error (line 3): 'endif' is not a valid delimiter for liquid tags. use %}", <<~LIQUID)
{%- if true -%}
42
{%- liquid endif -%}
LIQUID
end
def test_liquid_tag_in_raw

View File

@@ -127,7 +127,10 @@ class RenderTagTest < Minitest::Test
'test_include' => '{% include "foo" %}'
)
assert_template_result('include usage is not allowed in this context', '{% render "test_include" %}')
exc = assert_raises(Liquid::DisabledError) do
Liquid::Template.parse('{% render "test_include" %}').render!
end
assert_equal('Liquid error: include usage is not allowed in this context', exc.message)
end
def test_includes_will_not_render_inside_nested_sibling_tags
@@ -137,7 +140,8 @@ class RenderTagTest < Minitest::Test
'test_include' => '{% include "foo" %}'
)
assert_template_result('include usage is not allowed in this contextinclude usage is not allowed in this context', '{% render "nested_render_with_sibling_include" %}')
output = Liquid::Template.parse('{% render "nested_render_with_sibling_include" %}').render
assert_equal('Liquid error: include usage is not allowed in this contextLiquid error: include usage is not allowed in this context', output)
end
def test_render_tag_with

View File

@@ -111,13 +111,12 @@ class TemplateTest < Minitest::Test
def test_resource_limits_render_length
t = Template.parse("0123456789")
t.resource_limits.render_length_limit = 5
t.resource_limits.render_length_limit = 9
assert_equal("Liquid error: Memory limits exceeded", t.render)
assert(t.resource_limits.reached?)
t.resource_limits.render_length_limit = 10
assert_equal("0123456789", t.render!)
refute_nil(t.resource_limits.render_length)
end
def test_resource_limits_render_score
@@ -176,50 +175,46 @@ class TemplateTest < Minitest::Test
end
def test_resource_limits_hash_in_template_gets_updated_even_if_no_limits_are_set
t = Template.parse("{% for a in (1..100) %} {% assign foo = 1 %} {% endfor %}")
t = Template.parse("{% for a in (1..100) %}x{% assign foo = 1 %} {% endfor %}")
t.render!
assert(t.resource_limits.assign_score > 0)
assert(t.resource_limits.render_score > 0)
assert(t.resource_limits.render_length > 0)
end
def test_render_length_persists_between_blocks
t = Template.parse("{% if true %}aaaa{% endif %}")
t.resource_limits.render_length_limit = 7
t.resource_limits.render_length_limit = 3
assert_equal("Liquid error: Memory limits exceeded", t.render)
t.resource_limits.render_length_limit = 8
t.resource_limits.render_length_limit = 4
assert_equal("aaaa", t.render)
t = Template.parse("{% if true %}aaaa{% endif %}{% if true %}bbb{% endif %}")
t.resource_limits.render_length_limit = 13
t.resource_limits.render_length_limit = 6
assert_equal("Liquid error: Memory limits exceeded", t.render)
t.resource_limits.render_length_limit = 14
t.resource_limits.render_length_limit = 7
assert_equal("aaaabbb", t.render)
t = Template.parse("{% if true %}a{% endif %}{% if true %}b{% endif %}{% if true %}a{% endif %}{% if true %}b{% endif %}{% if true %}a{% endif %}{% if true %}b{% endif %}")
t.resource_limits.render_length_limit = 5
assert_equal("Liquid error: Memory limits exceeded", t.render)
t.resource_limits.render_length_limit = 11
assert_equal("Liquid error: Memory limits exceeded", t.render)
t.resource_limits.render_length_limit = 12
t.resource_limits.render_length_limit = 6
assert_equal("ababab", t.render)
end
def test_render_length_uses_number_of_bytes_not_characters
t = Template.parse("{% if true %}すごい{% endif %}")
t.resource_limits.render_length_limit = 10
t.resource_limits.render_length_limit = 8
assert_equal("Liquid error: Memory limits exceeded", t.render)
t.resource_limits.render_length_limit = 18
t.resource_limits.render_length_limit = 9
assert_equal("すごい", t.render)
end
def test_default_resource_limits_unaffected_by_render_with_context
context = Context.new
t = Template.parse("{% for a in (1..100) %} {% assign foo = 1 %} {% endfor %}")
t = Template.parse("{% for a in (1..100) %}x{% assign foo = 1 %} {% endfor %}")
t.render!(context)
assert(context.resource_limits.assign_score > 0)
assert(context.resource_limits.render_score > 0)
assert(context.resource_limits.render_length > 0)
end
def test_can_use_drop_as_context
@@ -361,48 +356,4 @@ class TemplateTest < Minitest::Test
result = t.render('x' => 1, 'y' => 5)
assert_equal('12345', result)
end
def test_render_uses_correct_disabled_tags_instance
Liquid::Template.file_system = StubFileSystem.new(
'foo' => 'bar',
'test_include' => '{% include "foo" %}'
)
disabled_tags = DisabledTags.new
context = Context.build(registers: { disabled_tags: disabled_tags })
source = "{% render 'test_include' %}"
parse_context = Liquid::ParseContext.new(line_numbers: true, error_mode: :strict)
document = Document.parse(Liquid::Tokenizer.new(source, true), parse_context)
assert_equal("include usage is not allowed in this context", document.render(context))
end
def test_render_sets_context_static_register_when_register_key_does_exist
disabled_tags_for_test = DisabledTags.new
Template.add_register(:disabled_tags, disabled_tags_for_test)
t = Template.parse("{% if true %} Test Template {% endif %}")
context = Context.new
refute(context.registers.key?(:disabled_tags))
t.render(context)
assert(context.registers.key?(:disabled_tags))
assert_equal(disabled_tags_for_test, context.registers[:disabled_tags])
end
def test_render_does_not_override_context_static_register_when_register_key_exists
context = Context.new
context.registers[:random_register] = nil
Template.add_register(:random_register, {})
t = Template.parse("{% if true %} Test Template {% endif %}")
t.render(context)
assert_nil(context.registers[:random_register])
assert(context.registers.key?(:random_register))
end
end

View File

@@ -528,4 +528,32 @@ class TrimModeTest < Minitest::Test
END_EXPECTED
assert_template_result(expected, text)
end
def test_pre_trim_blank_preceding_text
template = Liquid::Template.parse("\n{%- raw %}{% endraw %}")
assert_equal("", template.render)
template = Liquid::Template.parse("\n{%- if true %}{% endif %}")
assert_equal("", template.render)
template = Liquid::Template.parse("{{ 'B' }} \n{%- if true %}C{% endif %}")
assert_equal("BC", template.render)
end
def test_bug_compatible_pre_trim
template = Liquid::Template.parse("\n {%- raw %}{% endraw %}", bug_compatible_whitespace_trimming: true)
assert_equal("\n", template.render)
template = Liquid::Template.parse("\n {%- if true %}{% endif %}", bug_compatible_whitespace_trimming: true)
assert_equal("\n", template.render)
template = Liquid::Template.parse("{{ 'B' }} \n{%- if true %}C{% endif %}", bug_compatible_whitespace_trimming: true)
assert_equal("B C", template.render)
template = Liquid::Template.parse("B\n {%- raw %}{% endraw %}", bug_compatible_whitespace_trimming: true)
assert_equal("B", template.render)
template = Liquid::Template.parse("B\n {%- if true %}{% endif %}", bug_compatible_whitespace_trimming: true)
assert_equal("B", template.render)
end
end # TrimModeTest

View File

@@ -98,10 +98,17 @@ module Minitest
end
def with_custom_tag(tag_name, tag_class)
Liquid::Template.register_tag(tag_name, tag_class)
yield
ensure
Liquid::Template.tags.delete(tag_name)
old_tag = Liquid::Template.tags[tag_name]
begin
Liquid::Template.register_tag(tag_name, tag_class)
yield
ensure
if old_tag
Liquid::Template.tags[tag_name] = old_tag
else
Liquid::Template.tags.delete(tag_name)
end
end
end
end
end

View File

@@ -45,53 +45,9 @@ class BlockUnitTest < Minitest::Test
assert_equal(3, template.root.nodelist.size)
end
def test_with_custom_tag
with_custom_tag('testtag', Block) do
assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
end
end
def test_custom_block_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
klass1 = Class.new(Block) do
def render(*)
'hello'
end
end
with_custom_tag('blabla', klass1) do
template = Liquid::Template.parse("{% blabla %} bla {% endblabla %}")
assert_equal 'hello', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'hello', output
assert_equal 'hello', buf
assert_equal buf.object_id, output.object_id
end
klass2 = Class.new(klass1) do
def render(*)
'foo' + super + 'bar'
end
end
with_custom_tag('blabla', klass2) do
template = Liquid::Template.parse("{% blabla %} foo {% endblabla %}")
assert_equal 'foohellobar', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'foohellobar', output
assert_equal 'foohellobar', buf
assert_equal buf.object_id, output.object_id
end
end
private
def block_types(nodelist)
nodelist.collect(&:class)
end
end # VariableTest
end

View File

@@ -1,36 +0,0 @@
# frozen_string_literal: true
require 'test_helper'
class DisabledTagsUnitTest < Minitest::Test
include Liquid
def test_disables_tag_specified
register = DisabledTags.new
register.disable(%w(foo bar)) do
assert_equal true, register.disabled?("foo")
assert_equal true, register.disabled?("bar")
assert_equal false, register.disabled?("unknown")
end
end
def test_disables_nested_tags
register = DisabledTags.new
register.disable(["foo"]) do
register.disable(["foo"]) do
assert_equal true, register.disabled?("foo")
assert_equal false, register.disabled?("bar")
end
register.disable(["bar"]) do
assert_equal true, register.disabled?("foo")
assert_equal true, register.disabled?("bar")
register.disable(["foo"]) do
assert_equal true, register.disabled?("foo")
assert_equal true, register.disabled?("bar")
end
end
assert_equal true, register.disabled?("foo")
assert_equal false, register.disabled?("bar")
end
end
end

View File

@@ -20,42 +20,4 @@ class TagUnitTest < Minitest::Test
tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
assert_equal('some_tag', tag.tag_name)
end
def test_custom_tags_have_a_default_render_to_output_buffer_method_for_backwards_compatibility
klass1 = Class.new(Tag) do
def render(*)
'hello'
end
end
with_custom_tag('blabla', klass1) do
template = Liquid::Template.parse("{% blabla %}")
assert_equal 'hello', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'hello', output
assert_equal 'hello', buf
assert_equal buf.object_id, output.object_id
end
klass2 = Class.new(klass1) do
def render(*)
'foo' + super + 'bar'
end
end
with_custom_tag('blabla', klass2) do
template = Liquid::Template.parse("{% blabla %}")
assert_equal 'foohellobar', template.render
buf = +''
output = template.render({}, output: buf)
assert_equal 'foohellobar', output
assert_equal 'foohellobar', buf
assert_equal buf.object_id, output.object_id
end
end
end