Merge branch 'master' into sort-numeric

test/integration/assign_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class AssignTest < Minitest::Test

test/integration/blank_test.rb

@@ -1,11 +1,12 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class FoobarTag < Liquid::Tag
-  def render(*args)
-    " "
+  def render_to_output_buffer(_context, output)
+    output << ' '
+    output
   end
-
-  Liquid::Template.register_tag('foobar', FoobarTag)
 end
 
 class BlankTestFileSystem
@@ -31,7 +32,9 @@ class BlankTest < Minitest::Test
   end
 
   def test_new_tags_are_not_blank_by_default
-    assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
+    with_custom_tag('foobar', FoobarTag) do
+      assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
+    end
   end
 
   def test_loops_are_blank

test/integration/block_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class BlockTest < Minitest::Test

test/integration/capture_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class CaptureTest < Minitest::Test

test/integration/context_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContextTest < Minitest::Test

test/integration/document_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class DocumentTest < Minitest::Test

test/integration/drop_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContextDrop < Liquid::Drop
@@ -31,7 +33,7 @@ class ProductDrop < Liquid::Drop
 
   class CatchallDrop < Liquid::Drop
     def liquid_method_missing(method)
-      'catchall_method: ' << method.to_s
+      "catchall_method: #{method}"
     end
   end
 
@@ -48,7 +50,7 @@ class ProductDrop < Liquid::Drop
   end
 
   def user_input
-    "foo".taint
+    (+"foo").taint
   end
 
   protected
@@ -201,9 +203,9 @@ class DropsTest < Minitest::Test
   end
 
   def test_scope_though_proc
-    assert_equal '1', Liquid::Template.parse('{{ s }}').render!('context' => ContextDrop.new, 's' => proc{ |c| c['context.scopes'] })
-    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ s }}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc{ |c| c['context.scopes'] }, 'dummy' => [1])
-    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ s }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc{ |c| c['context.scopes'] }, 'dummy' => [1])
+    assert_equal '1', Liquid::Template.parse('{{ s }}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] })
+    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ s }}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1])
+    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ s }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc { |c| c['context.scopes'] }, 'dummy' => [1])
   end
 
   def test_scope_with_assigns
@@ -241,7 +243,7 @@ class DropsTest < Minitest::Test
   end
 
   def test_some_enumerable_methods_still_get_invoked
-    [ :count, :max ].each do |method|
+    [:count, :max].each do |method|
       assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
@@ -250,7 +252,7 @@ class DropsTest < Minitest::Test
 
     assert_equal "yes", Liquid::Template.parse("{% if collection contains 3 %}yes{% endif %}").render!('collection' => RealEnumerableDrop.new)
 
-    [ :min, :first ].each do |method|
+    [:min, :first].each do |method|
       assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
       assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
@@ -270,4 +272,11 @@ class DropsTest < Minitest::Test
     assert_equal 'ProductDrop', Liquid::Template.parse("{{ product }}").render!('product' => ProductDrop.new)
     assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render!('collection' => EnumerableDrop.new)
   end
+
+  def test_invokable_methods
+    assert_equal %w(to_liquid catchall user_input context texts).to_set, ProductDrop.invokable_methods
+    assert_equal %w(to_liquid scopes_as_array loop_pos scopes).to_set, ContextDrop.invokable_methods
+    assert_equal %w(to_liquid size max min first count).to_set, EnumerableDrop.invokable_methods
+    assert_equal %w(to_liquid max min sort count first).to_set, RealEnumerableDrop.invokable_methods
+  end
 end # DropsTest

test/integration/error_handling_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ErrorHandlingTest < Minitest::Test
@@ -83,15 +85,14 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_with_line_numbers_adds_numbers_to_parser_errors
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse(%q(
+      Liquid::Template.parse('
           foobar
 
           {% "cat" | foobar %}
 
           bla
-        ),
-        line_numbers: true
-      )
+        ',
+        line_numbers: true)
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -99,15 +100,14 @@ class ErrorHandlingTest < Minitest::Test
 
   def test_with_line_numbers_adds_numbers_to_parser_errors_with_whitespace_trim
     err = assert_raises(SyntaxError) do
-      Liquid::Template.parse(%q(
+      Liquid::Template.parse('
           foobar
 
           {%- "cat" | foobar -%}
 
           bla
-        ),
-        line_numbers: true
-      )
+        ',
+        line_numbers: true)
     end
 
     assert_match(/Liquid syntax error \(line 4\)/, err.message)
@@ -122,8 +122,7 @@ class ErrorHandlingTest < Minitest::Test
         bla
             ',
       error_mode: :warn,
-      line_numbers: true
-                                     )
+      line_numbers: true)
 
     assert_equal ['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
       template.warnings.map(&:message)
@@ -139,8 +138,7 @@ class ErrorHandlingTest < Minitest::Test
           bla
                 ',
         error_mode: :strict,
-        line_numbers: true
-                            )
+        line_numbers: true)
     end
 
     assert_equal 'Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message
@@ -157,8 +155,7 @@ class ErrorHandlingTest < Minitest::Test
 
           bla
                 ',
-        line_numbers: true
-                            )
+        line_numbers: true)
     end
 
     assert_equal "Liquid syntax error (line 5): Unknown tag 'foo'", err.message
@@ -205,7 +202,7 @@ class ErrorHandlingTest < Minitest::Test
   def test_default_exception_renderer_with_internal_error
     template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
 
-    output = template.render({ 'errors' => ErrorDrop.new })
+    output = template.render('errors' => ErrorDrop.new)
 
     assert_equal 'This is a runtime error: Liquid error (line 1): internal', output
     assert_equal [Liquid::InternalError], template.errors.map(&:class)
@@ -214,10 +211,13 @@ class ErrorHandlingTest < Minitest::Test
   def test_setting_default_exception_renderer
     old_exception_renderer = Liquid::Template.default_exception_renderer
     exceptions = []
-    Liquid::Template.default_exception_renderer = ->(e) { exceptions << e; '' }
+    Liquid::Template.default_exception_renderer = ->(e) {
+      exceptions << e
+      ''
+    }
     template = Liquid::Template.parse('This is a runtime error: {{ errors.argument_error }}')
 
-    output = template.render({ 'errors' => ErrorDrop.new })
+    output = template.render('errors' => ErrorDrop.new)
 
     assert_equal 'This is a runtime error: ', output
     assert_equal [Liquid::ArgumentError], template.errors.map(&:class)
@@ -228,7 +228,10 @@ class ErrorHandlingTest < Minitest::Test
   def test_exception_renderer_exposing_non_liquid_error
     template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
     exceptions = []
-    handler = ->(e) { exceptions << e; e.cause }
+    handler = ->(e) {
+      exceptions << e
+      e.cause
+    }
 
     output = template.render({ 'errors' => ErrorDrop.new }, exception_renderer: handler)
 
@@ -239,7 +242,7 @@ class ErrorHandlingTest < Minitest::Test
   end
 
   class TestFileSystem
-    def read_template_file(template_path)
+    def read_template_file(_template_path)
       "{{ errors.argument_error }}"
     end
   end

test/integration/filter_test.rb

@@ -1,24 +1,26 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module MoneyFilter
   def money(input)
-    sprintf(' %d$ ', input)
+    format(' %d$ ', input)
   end
 
   def money_with_underscore(input)
-    sprintf(' %d$ ', input)
+    format(' %d$ ', input)
   end
 end
 
 module CanadianMoneyFilter
   def money(input)
-    sprintf(' %d$ CAD ', input)
+    format(' %d$ CAD ', input)
   end
 end
 
 module SubstituteFilter
   def substitute(input, params = {})
-    input.gsub(/%\{(\w+)\}/) { |match| params[$1] }
+    input.gsub(/%\{(\w+)\}/) { |_match| params[Regexp.last_match(1)] }
   end
 end
 
@@ -26,7 +28,7 @@ class FiltersTest < Minitest::Test
   include Liquid
 
   module OverrideObjectMethodFilter
-    def tap(input)
+    def tap(_input)
       "tap overridden"
     end
   end
@@ -149,7 +151,7 @@ class FiltersTest < Minitest::Test
     assert_equal "tap overridden", Template.parse("{{var | tap}}").render!({ 'var' => 1000 }, filters: [OverrideObjectMethodFilter])
 
     # tap still treated as a non-existent filter
-    assert_equal "1000", Template.parse("{{var | tap}}").render!({ 'var' => 1000 })
+    assert_equal "1000", Template.parse("{{var | tap}}").render!('var' => 1000)
   end
 end
 

test/integration/hash_ordering_test.rb

@@ -1,15 +1,17 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class HashOrderingTest < Minitest::Test
   module MoneyFilter
     def money(input)
-      sprintf(' %d$ ', input)
+      format(' %d$ ', input)
     end
   end
 
   module CanadianMoneyFilter
     def money(input)
-      sprintf(' %d$ CAD ', input)
+      format(' %d$ CAD ', input)
     end
   end
 

test/integration/output_test.rb

@@ -1,7 +1,9 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module FunnyFilter
-  def make_funny(input)
+  def make_funny(_input)
     'LOL'
   end
 
@@ -32,7 +34,7 @@ class OutputTest < Minitest::Test
   def setup
     @assigns = {
       'best_cars' => 'bmw',
-      'car' => { 'bmw' => 'good', 'gm' => 'bad' }
+      'car' => { 'bmw' => 'good', 'gm' => 'bad' },
     }
   end
 

test/integration/parse_tree_visitor_test.rb

@@ -0,0 +1,247 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class ParseTreeVisitorTest < Minitest::Test
+  include Liquid
+
+  def test_variable
+    assert_equal(
+      ["test"],
+      visit(%({{ test }}))
+    )
+  end
+
+  def test_varible_with_filter
+    assert_equal(
+      ["test", "infilter"],
+      visit(%({{ test | split: infilter }}))
+    )
+  end
+
+  def test_dynamic_variable
+    assert_equal(
+      ["test", "inlookup"],
+      visit(%({{ test[inlookup] }}))
+    )
+  end
+
+  def test_if_condition
+    assert_equal(
+      ["test"],
+      visit(%({% if test %}{% endif %}))
+    )
+  end
+
+  def test_complex_if_condition
+    assert_equal(
+      ["test"],
+      visit(%({% if 1 == 1 and 2 == test %}{% endif %}))
+    )
+  end
+
+  def test_if_body
+    assert_equal(
+      ["test"],
+      visit(%({% if 1 == 1 %}{{ test }}{% endif %}))
+    )
+  end
+
+  def test_unless_condition
+    assert_equal(
+      ["test"],
+      visit(%({% unless test %}{% endunless %}))
+    )
+  end
+
+  def test_complex_unless_condition
+    assert_equal(
+      ["test"],
+      visit(%({% unless 1 == 1 and 2 == test %}{% endunless %}))
+    )
+  end
+
+  def test_unless_body
+    assert_equal(
+      ["test"],
+      visit(%({% unless 1 == 1 %}{{ test }}{% endunless %}))
+    )
+  end
+
+  def test_elsif_condition
+    assert_equal(
+      ["test"],
+      visit(%({% if 1 == 1 %}{% elsif test %}{% endif %}))
+    )
+  end
+
+  def test_complex_elsif_condition
+    assert_equal(
+      ["test"],
+      visit(%({% if 1 == 1 %}{% elsif 1 == 1 and 2 == test %}{% endif %}))
+    )
+  end
+
+  def test_elsif_body
+    assert_equal(
+      ["test"],
+      visit(%({% if 1 == 1 %}{% elsif 2 == 2 %}{{ test }}{% endif %}))
+    )
+  end
+
+  def test_else_body
+    assert_equal(
+      ["test"],
+      visit(%({% if 1 == 1 %}{% else %}{{ test }}{% endif %}))
+    )
+  end
+
+  def test_case_left
+    assert_equal(
+      ["test"],
+      visit(%({% case test %}{% endcase %}))
+    )
+  end
+
+  def test_case_condition
+    assert_equal(
+      ["test"],
+      visit(%({% case 1 %}{% when test %}{% endcase %}))
+    )
+  end
+
+  def test_case_when_body
+    assert_equal(
+      ["test"],
+      visit(%({% case 1 %}{% when 2 %}{{ test }}{% endcase %}))
+    )
+  end
+
+  def test_case_else_body
+    assert_equal(
+      ["test"],
+      visit(%({% case 1 %}{% else %}{{ test }}{% endcase %}))
+    )
+  end
+
+  def test_for_in
+    assert_equal(
+      ["test"],
+      visit(%({% for x in test %}{% endfor %}))
+    )
+  end
+
+  def test_for_limit
+    assert_equal(
+      ["test"],
+      visit(%({% for x in (1..5) limit: test %}{% endfor %}))
+    )
+  end
+
+  def test_for_offset
+    assert_equal(
+      ["test"],
+      visit(%({% for x in (1..5) offset: test %}{% endfor %}))
+    )
+  end
+
+  def test_for_body
+    assert_equal(
+      ["test"],
+      visit(%({% for x in (1..5) %}{{ test }}{% endfor %}))
+    )
+  end
+
+  def test_tablerow_in
+    assert_equal(
+      ["test"],
+      visit(%({% tablerow x in test %}{% endtablerow %}))
+    )
+  end
+
+  def test_tablerow_limit
+    assert_equal(
+      ["test"],
+      visit(%({% tablerow x in (1..5) limit: test %}{% endtablerow %}))
+    )
+  end
+
+  def test_tablerow_offset
+    assert_equal(
+      ["test"],
+      visit(%({% tablerow x in (1..5) offset: test %}{% endtablerow %}))
+    )
+  end
+
+  def test_tablerow_body
+    assert_equal(
+      ["test"],
+      visit(%({% tablerow x in (1..5) %}{{ test }}{% endtablerow %}))
+    )
+  end
+
+  def test_cycle
+    assert_equal(
+      ["test"],
+      visit(%({% cycle test %}))
+    )
+  end
+
+  def test_assign
+    assert_equal(
+      ["test"],
+      visit(%({% assign x = test %}))
+    )
+  end
+
+  def test_capture
+    assert_equal(
+      ["test"],
+      visit(%({% capture x %}{{ test }}{% endcapture %}))
+    )
+  end
+
+  def test_include
+    assert_equal(
+      ["test"],
+      visit(%({% include test %}))
+    )
+  end
+
+  def test_include_with
+    assert_equal(
+      ["test"],
+      visit(%({% include "hai" with test %}))
+    )
+  end
+
+  def test_include_for
+    assert_equal(
+      ["test"],
+      visit(%({% include "hai" for test %}))
+    )
+  end
+
+  def test_preserve_tree_structure
+    assert_equal(
+      [[nil, [
+        [nil, [[nil, [["other", []]]]]],
+        ["test", []],
+        ["xs", []],
+      ]]],
+      traversal(%({% for x in xs offset: test %}{{ other }}{% endfor %})).visit
+    )
+  end
+
+  private
+
+  def traversal(template)
+    ParseTreeVisitor
+      .for(Template.parse(template).root)
+      .add_callback_for(VariableLookup, &:name)
+  end
+
+  def visit(template)
+    traversal(template).visit.flatten.compact
+  end
+end

test/integration/parsing_quirks_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ParsingQuirksTest < Minitest::Test
@@ -99,7 +101,7 @@ class ParsingQuirksTest < Minitest::Test
       # After the messed up quotes a filter without parameters (reverse) should work
       # but one with parameters (remove) shouldn't be detected.
       assert_template_result('here',  "{{ 'hi there' | split:\"t\"\" | reverse | first}}")
-      assert_template_result('hi ',  "{{ 'hi there' | split:\"t\"\" | remove:\"i\" | first}}")
+      assert_template_result('hi ', "{{ 'hi there' | split:\"t\"\" | remove:\"i\" | first}}")
     end
   end
 

test/integration/registers/disabled_tags_test.rb

@@ -0,0 +1,27 @@
+# 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

test/integration/render_profiling_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RenderProfilingTest < Minitest::Test
@@ -128,7 +130,7 @@ class RenderProfilingTest < Minitest::Test
     t.render!
 
     timing_count = 0
-    t.profiler.each do |timing|
+    t.profiler.each do |_timing|
       timing_count += 1
     end
 
@@ -145,7 +147,7 @@ class RenderProfilingTest < Minitest::Test
 
   def test_profiling_marks_children_of_for_blocks
     t = Template.parse("{% for item in collection %} {{ item }} {% endfor %}", profile: true)
-    t.render!({ "collection" => ["one", "two"] })
+    t.render!("collection" => ["one", "two"])
 
     assert_equal 1, t.profiler.length
     # Will profile each invocation of the for block

test/integration/security_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 module SecurityFilter

test/integration/standard_filter_test.rb

@@ -1,4 +1,5 @@
 # encoding: utf-8
+# frozen_string_literal: true
 
 require 'test_helper'
 
@@ -17,7 +18,7 @@ class TestThing
     "woot: #{@foo}"
   end
 
-  def [](whatever)
+  def [](_whatever)
     to_s
   end
 
@@ -37,7 +38,7 @@ class TestEnumerable < Liquid::Drop
   include Enumerable
 
   def each(&block)
-    [ { "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 } ].each(&block)
+    [{ "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 }].each(&block)
   end
 end
 
@@ -158,6 +159,10 @@ class StandardFiltersTest < Minitest::Test
     assert_equal '1', @filters.url_decode(1)
     assert_equal '2001-02-03', @filters.url_decode(Date.new(2001, 2, 3))
     assert_nil @filters.url_decode(nil)
+    exception = assert_raises Liquid::ArgumentError do
+      @filters.url_decode('%ff')
+    end
+    assert_equal 'Liquid error: invalid byte sequence in UTF-8', exception.message
   end
 
   def test_truncatewords
@@ -177,6 +182,9 @@ class StandardFiltersTest < Minitest::Test
     assert_equal 'test', @filters.strip_html("<div\nclass='multiline'>test</div>")
     assert_equal 'test', @filters.strip_html("<!-- foo bar \n test -->test")
     assert_equal '', @filters.strip_html(nil)
+
+    # Quirk of the existing implementation
+    assert_equal 'foo;', @filters.strip_html("<<<script </script>script>foo;</script>")
   end
 
   def test_join
@@ -192,9 +200,13 @@ class StandardFiltersTest < Minitest::Test
 
   def test_sort_numeric
     assert_equal ['1', '2', '3', '10'], @filters.sort_numeric(['10', '3', '2', '1'])
-
     assert_equal [{ "a" => '1' }, { "a" => '2' }, { "a" => '3' }, { "a" => '10' }],
       @filters.sort_numeric([{ "a" => '10' }, { "a" => '3' }, { "a" => '1' }, { "a" => '2' }], "a")
+  end  
+    
+  def test_sort_with_nils
+    assert_equal [1, 2, 3, 4, nil], @filters.sort([nil, 4, 3, 2, 1])
+    assert_equal [{ "a" => 1 }, { "a" => 2 }, { "a" => 3 }, { "a" => 4 }, {}], @filters.sort([{ "a" => 4 }, { "a" => 3 }, {}, { "a" => 1 }, { "a" => 2 }], "a")
   end
 
   def test_sort_when_property_is_sometimes_missing_puts_nils_last
@@ -203,22 +215,85 @@ class StandardFiltersTest < Minitest::Test
       { "handle" => "beta" },
       { "price" => 1, "handle" => "gamma" },
       { "handle" => "delta" },
-      { "price" => 2, "handle" => "epsilon" }
+      { "price" => 2, "handle" => "epsilon" },
     ]
     expectation = [
       { "price" => 1, "handle" => "gamma" },
       { "price" => 2, "handle" => "epsilon" },
       { "price" => 4, "handle" => "alpha" },
       { "handle" => "delta" },
-      { "handle" => "beta" }
+      { "handle" => "beta" },
     ]
     assert_equal expectation, @filters.sort(input, "price")
   end
 
+  def test_sort_natural
+    assert_equal ["a", "B", "c", "D"], @filters.sort_natural(["c", "D", "a", "B"])
+    assert_equal [{ "a" => "a" }, { "a" => "B" }, { "a" => "c" }, { "a" => "D" }], @filters.sort_natural([{ "a" => "D" }, { "a" => "c" }, { "a" => "a" }, { "a" => "B" }], "a")
+  end
+
+  def test_sort_natural_with_nils
+    assert_equal ["a", "B", "c", "D", nil], @filters.sort_natural([nil, "c", "D", "a", "B"])
+    assert_equal [{ "a" => "a" }, { "a" => "B" }, { "a" => "c" }, { "a" => "D" }, {}], @filters.sort_natural([{ "a" => "D" }, { "a" => "c" }, {}, { "a" => "a" }, { "a" => "B" }], "a")
+  end
+
+  def test_sort_natural_when_property_is_sometimes_missing_puts_nils_last
+    input = [
+      { "price" => "4", "handle" => "alpha" },
+      { "handle" => "beta" },
+      { "price" => "1", "handle" => "gamma" },
+      { "handle" => "delta" },
+      { "price" => 2, "handle" => "epsilon" },
+    ]
+    expectation = [
+      { "price" => "1", "handle" => "gamma" },
+      { "price" => 2, "handle" => "epsilon" },
+      { "price" => "4", "handle" => "alpha" },
+      { "handle" => "delta" },
+      { "handle" => "beta" },
+    ]
+    assert_equal expectation, @filters.sort_natural(input, "price")
+  end
+
+  def test_sort_natural_case_check
+    input = [
+      { "key" => "X" },
+      { "key" => "Y" },
+      { "key" => "Z" },
+      { "fake" => "t" },
+      { "key" => "a" },
+      { "key" => "b" },
+      { "key" => "c" },
+    ]
+    expectation = [
+      { "key" => "a" },
+      { "key" => "b" },
+      { "key" => "c" },
+      { "key" => "X" },
+      { "key" => "Y" },
+      { "key" => "Z" },
+      { "fake" => "t" },
+    ]
+    assert_equal expectation, @filters.sort_natural(input, "key")
+    assert_equal ["a", "b", "c", "X", "Y", "Z"], @filters.sort_natural(["X", "Y", "Z", "a", "b", "c"])
+  end
+
   def test_sort_empty_array
     assert_equal [], @filters.sort([], "a")
   end
 
+  def test_sort_invalid_property
+    foo = [
+      [1],
+      [2],
+      [3],
+    ]
+
+    assert_raises Liquid::ArgumentError do
+      @filters.sort(foo, "bar")
+    end
+  end
+
   def test_sort_natural_empty_array
     assert_equal [], @filters.sort_natural([], "a")
   end
@@ -226,9 +301,21 @@ class StandardFiltersTest < Minitest::Test
   def test_sort_numeric_empty_array
     assert_equal [], @filters.sort_numeric([], "a")
   end
+  
+  def test_sort_natural_invalid_property
+    foo = [
+      [1],
+      [2],
+      [3],
+    ]
+
+    assert_raises Liquid::ArgumentError do
+      @filters.sort_natural(foo, "bar")
+    end
+  end
 
   def test_legacy_sort_hash
-    assert_equal [{ a: 1, b: 2 }], @filters.sort({ a: 1, b: 2 })
+    assert_equal [{ a: 1, b: 2 }], @filters.sort(a: 1, b: 2)
   end
 
   def test_numerical_vs_lexicographical_sort
@@ -250,10 +337,34 @@ class StandardFiltersTest < Minitest::Test
     assert_equal [], @filters.uniq([], "a")
   end
 
+  def test_uniq_invalid_property
+    foo = [
+      [1],
+      [2],
+      [3],
+    ]
+
+    assert_raises Liquid::ArgumentError do
+      @filters.uniq(foo, "bar")
+    end
+  end
+
   def test_compact_empty_array
     assert_equal [], @filters.compact([], "a")
   end
 
+  def test_compact_invalid_property
+    foo = [
+      [1],
+      [2],
+      [3],
+    ]
+
+    assert_raises Liquid::ArgumentError do
+      @filters.compact(foo, "bar")
+    end
+  end
+
   def test_reverse
     assert_equal [4, 3, 2, 1], @filters.reverse([1, 2, 3, 4])
   end
@@ -280,7 +391,7 @@ class StandardFiltersTest < Minitest::Test
 
   def test_map_on_hashes
     assert_template_result "4217", '{{ thing | map: "foo" | map: "bar" }}',
-      "thing" => { "foo" => [ { "bar" => 42 }, { "bar" => 17 } ] }
+      "thing" => { "foo" => [{ "bar" => 42 }, { "bar" => 17 }] }
   end
 
   def test_legacy_map_on_hashes_with_dynamic_key
@@ -297,7 +408,7 @@ class StandardFiltersTest < Minitest::Test
 
   def test_map_over_proc
     drop = TestDrop.new
-    p = proc{ drop }
+    p = proc { drop }
     templ = '{{ procs | map: "test" }}'
     assert_template_result "testfoo", templ, "procs" => [p]
   end
@@ -305,10 +416,10 @@ class StandardFiltersTest < Minitest::Test
   def test_map_over_drops_returning_procs
     drops = [
       {
-        "proc" => ->{ "foo" },
+        "proc" => -> { "foo" },
       },
       {
-        "proc" => ->{ "bar" },
+        "proc" => -> { "bar" },
       },
     ]
     templ = '{{ drops | map: "proc" }}'
@@ -319,6 +430,29 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result "123", '{{ foo | map: "foo" }}', "foo" => TestEnumerable.new
   end
 
+  def test_map_returns_empty_on_2d_input_array
+    foo = [
+      [1],
+      [2],
+      [3],
+    ]
+
+    assert_raises Liquid::ArgumentError do
+      @filters.map(foo, "bar")
+    end
+  end
+
+  def test_map_returns_empty_with_no_property
+    foo = [
+      [1],
+      [2],
+      [3],
+    ]
+    assert_raises Liquid::ArgumentError do
+      @filters.map(foo, nil)
+    end
+  end
+
   def test_sort_works_on_enumerables
     assert_template_result "213", '{{ foo | sort: "bar" | map: "foo" }}', "foo" => TestEnumerable.new
   end
@@ -349,9 +483,9 @@ class StandardFiltersTest < Minitest::Test
     assert_equal '07/05/2006', @filters.date("2006-07-05 10:00:00", "%m/%d/%Y")
 
     assert_equal "07/16/2004", @filters.date("Fri Jul 16 01:00:00 2004", "%m/%d/%Y")
-    assert_equal "#{Date.today.year}", @filters.date('now', '%Y')
-    assert_equal "#{Date.today.year}", @filters.date('today', '%Y')
-    assert_equal "#{Date.today.year}", @filters.date('Today', '%Y')
+    assert_equal Date.today.year.to_s, @filters.date('now', '%Y')
+    assert_equal Date.today.year.to_s, @filters.date('today', '%Y')
+    assert_equal Date.today.year.to_s, @filters.date('Today', '%Y')
 
     assert_nil @filters.date(nil, "%B")
 
@@ -569,6 +703,78 @@ class StandardFiltersTest < Minitest::Test
     assert_template_result('abc', "{{ 'abc' | date: '%D' }}")
   end
 
+  def test_where
+    input = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta", "ok" => false },
+      { "handle" => "gamma", "ok" => false },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    expectation = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    assert_equal expectation, @filters.where(input, "ok", true)
+    assert_equal expectation, @filters.where(input, "ok")
+  end
+
+  def test_where_no_key_set
+    input = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "beta" },
+      { "handle" => "gamma" },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    expectation = [
+      { "handle" => "alpha", "ok" => true },
+      { "handle" => "delta", "ok" => true },
+    ]
+
+    assert_equal expectation, @filters.where(input, "ok", true)
+    assert_equal expectation, @filters.where(input, "ok")
+  end
+
+  def test_where_non_array_map_input
+    assert_equal [{ "a" => "ok" }], @filters.where({ "a" => "ok" }, "a", "ok")
+    assert_equal [], @filters.where({ "a" => "not ok" }, "a", "ok")
+  end
+
+  def test_where_indexable_but_non_map_value
+    assert_raises(Liquid::ArgumentError) { @filters.where(1, "ok", true) }
+    assert_raises(Liquid::ArgumentError) { @filters.where(1, "ok") }
+  end
+
+  def test_where_non_boolean_value
+    input = [
+      { "message" => "Bonjour!", "language" => "French" },
+      { "message" => "Hello!", "language" => "English" },
+      { "message" => "Hallo!", "language" => "German" },
+    ]
+
+    assert_equal [{ "message" => "Bonjour!", "language" => "French" }], @filters.where(input, "language", "French")
+    assert_equal [{ "message" => "Hallo!", "language" => "German" }], @filters.where(input, "language", "German")
+    assert_equal [{ "message" => "Hello!", "language" => "English" }], @filters.where(input, "language", "English")
+  end
+
+  def test_where_array_of_only_unindexable_values
+    assert_nil @filters.where([nil], "ok", true)
+    assert_nil @filters.where([nil], "ok")
+  end
+
+  def test_where_no_target_value
+    input = [
+      { "foo" => false },
+      { "foo" => true },
+      { "foo" => "for sure" },
+      { "bar" => true },
+    ]
+
+    assert_equal [{ "foo" => true }, { "foo" => "for sure" }], @filters.where(input, "foo")
+  end
+
   private
 
   def with_timezone(tz)

test/integration/tags/break_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class BreakTagTest < Minitest::Test

test/integration/tags/continue_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ContinueTagTest < Minitest::Test

test/integration/tags/echo_test.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class EchoTest < Minitest::Test
+  include Liquid
+
+  def test_echo_outputs_its_input
+    assert_template_result('BAR', <<~LIQUID, 'variable-name' => 'bar')
+      {%- echo variable-name | upcase -%}
+    LIQUID
+  end
+end

test/integration/tags/for_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ThingWithValue < Liquid::Drop
@@ -23,16 +25,16 @@ class ForTagTest < Minitest::Test
   yo
 
 HERE
-    template = <<HERE
-{%for item in array%}
-  yo
-{%endfor%}
-HERE
+    template = <<~HERE
+      {%for item in array%}
+        yo
+      {%endfor%}
+    HERE
     assert_template_result(expected, template, 'array' => [1, 2, 3])
   end
 
   def test_for_reversed
-    assigns = { 'array' => [ 1, 2, 3] }
+    assigns = { 'array' => [1, 2, 3] }
     assert_template_result('321', '{%for item in array reversed %}{{item}}{%endfor%}', assigns)
   end
 
@@ -103,6 +105,34 @@ HERE
     assert_template_result('3456', '{%for i in array limit: 4 offset: 2 %}{{ i }}{%endfor%}', assigns)
   end
 
+  def test_limiting_with_invalid_limit
+    assigns = { 'array' => [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] }
+    template = <<-MKUP
+      {% for i in array limit: true offset: 1 %}
+        {{ i }}
+      {% endfor %}
+    MKUP
+
+    exception = assert_raises(Liquid::ArgumentError) do
+      Template.parse(template).render!(assigns)
+    end
+    assert_equal("Liquid error: invalid integer", exception.message)
+  end
+
+  def test_limiting_with_invalid_offset
+    assigns = { 'array' => [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] }
+    template = <<-MKUP
+      {% for i in array limit: 1 offset: true %}
+        {{ i }}
+      {% endfor %}
+    MKUP
+
+    exception = assert_raises(Liquid::ArgumentError) do
+      Template.parse(template).render!(assigns)
+    end
+    assert_equal("Liquid error: invalid integer", exception.message)
+  end
+
   def test_dynamic_variable_limiting
     assigns = { 'array' => [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] }
     assigns['limit'] = 2

test/integration/tags/if_else_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IfElseTagTest < Minitest::Test
@@ -132,7 +134,7 @@ class IfElseTagTest < Minitest::Test
   end
 
   def test_syntax_error_no_variable
-    assert_raises(SyntaxError){ assert_template_result('', '{% if jerry == 1 %}') }
+    assert_raises(SyntaxError) { assert_template_result('', '{% if jerry == 1 %}') }
   end
 
   def test_syntax_error_no_expression

test/integration/tags/include_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TestFileSystem
@@ -30,6 +32,9 @@ class TestFileSystem
     when 'assignments'
       "{% assign foo = 'bar' %}"
 
+    when 'break'
+      "{% break %}"
+
     else
       template_path
     end
@@ -37,14 +42,14 @@ class TestFileSystem
 end
 
 class OtherFileSystem
-  def read_template_file(template_path)
+  def read_template_file(_template_path)
     'from OtherFileSystem'
   end
 end
 
 class CountingFileSystem
   attr_reader :count
-  def read_template_file(template_path)
+  def read_template_file(_template_path)
     @count ||= 0
     @count += 1
     'from CountingFileSystem'
@@ -56,15 +61,16 @@ class CustomInclude < Liquid::Tag
 
   def initialize(tag_name, markup, tokens)
     markup =~ Syntax
-    @template_name = $1
+    @template_name = Regexp.last_match(1)
     super
   end
 
   def parse(tokens)
   end
 
-  def render(context)
-    @template_name[1..-2]
+  def render_to_output_buffer(_context, output)
+    output << @template_name[1..-2]
+    output
   end
 end
 
@@ -82,7 +88,7 @@ class IncludeTagTest < Minitest::Test
 
   def test_include_tag_with
     assert_template_result "Product: Draft 151cm ",
-      "{% include 'product' with products[0] %}", "products" => [ { 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' } ]
+      "{% include 'product' with products[0] %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }]
   end
 
   def test_include_tag_with_default_name
@@ -92,7 +98,7 @@ class IncludeTagTest < Minitest::Test
 
   def test_include_tag_for
     assert_template_result "Product: Draft 151cm Product: Element 155cm ",
-      "{% include 'product' for products %}", "products" => [ { 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' } ]
+      "{% include 'product' for products %}", "products" => [{ 'title' => 'Draft 151cm' }, { 'title' => 'Element 155cm' }]
   end
 
   def test_include_tag_with_local_variables
@@ -130,7 +136,7 @@ class IncludeTagTest < Minitest::Test
 
   def test_recursively_included_template_does_not_produce_endless_loop
     infinite_file_system = Class.new do
-      def read_template_file(template_path)
+      def read_template_file(_template_path)
         "-{% include 'loop' %}"
       end
     end
@@ -242,4 +248,9 @@ class IncludeTagTest < Minitest::Test
 
     assert_equal [], template.errors
   end
+
+  def test_break_through_include
+    assert_template_result "1", "{% for i in (1..3) %}{{ i }}{% break %}{{ i }}{% endfor %}"
+    assert_template_result "1", "{% for i in (1..3) %}{{ i }}{% include 'break' %}{{ i }}{% endfor %}"
+  end
 end # IncludeTagTest

test/integration/tags/increment_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IncrementTagTest < Minitest::Test
@@ -13,11 +15,11 @@ class IncrementTagTest < Minitest::Test
   end
 
   def test_dec
-    assert_template_result('9', '{%decrement port %}', { 'port' => 10 })
+    assert_template_result('9', '{%decrement port %}', 'port' => 10)
     assert_template_result('-1 -2', '{%decrement port %} {%decrement port%}', {})
     assert_template_result('1 5 2 2 5',
       '{%increment port %} {%increment starboard%} ' \
       '{%increment port %} {%decrement port%} ' \
-      '{%decrement starboard %}', { 'port' => 1, 'starboard' => 5 })
+      '{%decrement starboard %}', 'port' => 1, 'starboard' => 5)
   end
 end

test/integration/tags/liquid_tag_test.rb

@@ -0,0 +1,106 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class LiquidTagTest < Minitest::Test
+  include Liquid
+
+  def test_liquid_tag
+    assert_template_result('1 2 3', <<~LIQUID, 'array' => [1, 2, 3])
+      {%- liquid
+        echo array | join: " "
+      -%}
+    LIQUID
+
+    assert_template_result('1 2 3', <<~LIQUID, 'array' => [1, 2, 3])
+      {%- liquid
+        for value in array
+          echo value
+          unless forloop.last
+            echo " "
+          endunless
+        endfor
+      -%}
+    LIQUID
+
+    assert_template_result('4 8 12 6', <<~LIQUID, 'array' => [1, 2, 3])
+      {%- liquid
+        for value in array
+          assign double_value = value | times: 2
+          echo double_value | times: 2
+          unless forloop.last
+            echo " "
+          endunless
+        endfor
+
+        echo " "
+        echo double_value
+      -%}
+    LIQUID
+
+    assert_template_result('abc', <<~LIQUID)
+      {%- liquid echo "a" -%}
+      b
+      {%- liquid echo "c" -%}
+    LIQUID
+  end
+
+  def test_liquid_tag_errors
+    assert_match_syntax_error("syntax error (line 1): Unknown tag 'error'", <<~LIQUID)
+      {%- liquid error no such tag -%}
+    LIQUID
+
+    assert_match_syntax_error("syntax error (line 7): Unknown tag 'error'", <<~LIQUID)
+      {{ test }}
+
+      {%-
+      liquid
+        for value in array
+
+          error no such tag
+        endfor
+      -%}
+    LIQUID
+
+    assert_match_syntax_error("syntax error (line 2): Unknown tag '!!! the guards are vigilant'", <<~LIQUID)
+      {%- liquid
+        !!! the guards are vigilant
+      -%}
+    LIQUID
+
+    assert_match_syntax_error("syntax error (line 4): 'for' tag was never closed", <<~LIQUID)
+      {%- liquid
+        for value in array
+          echo 'forgot to close the for tag'
+      -%}
+    LIQUID
+  end
+
+  def test_line_number_is_correct_after_a_blank_token
+    assert_match_syntax_error("syntax error (line 3): Unknown tag 'error'", "{% liquid echo ''\n\n error %}")
+    assert_match_syntax_error("syntax error (line 3): Unknown tag 'error'", "{% liquid echo ''\n  \n error %}")
+  end
+
+  def test_cannot_open_blocks_living_past_a_liquid_tag
+    assert_match_syntax_error("syntax error (line 3): 'if' tag was never closed", <<~LIQUID)
+      {%- liquid
+        if true
+      -%}
+      {%- endif -%}
+    LIQUID
+  end
+
+  def test_quirk_can_close_blocks_created_before_a_liquid_tag
+    assert_template_result("42", <<~LIQUID)
+      {%- if true -%}
+      42
+      {%- liquid endif -%}
+    LIQUID
+  end
+
+  def test_liquid_tag_in_raw
+    assert_template_result("{% liquid echo 'test' %}\n", <<~LIQUID)
+      {% raw %}{% liquid echo 'test' %}{% endraw %}
+    LIQUID
+  end
+end

test/integration/tags/raw_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RawTagTest < Minitest::Test

test/integration/tags/render_tag_test.rb

@@ -0,0 +1,168 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class RenderTagTest < Minitest::Test
+  include Liquid
+
+  def test_render_with_no_arguments
+    Liquid::Template.file_system = StubFileSystem.new('source' => 'rendered content')
+    assert_template_result 'rendered content', '{% render "source" %}'
+  end
+
+  def test_render_tag_looks_for_file_system_in_registers_first
+    file_system = StubFileSystem.new('pick_a_source' => 'from register file system')
+    assert_equal 'from register file system',
+      Template.parse('{% render "pick_a_source" %}').render!({}, registers: { file_system: file_system })
+  end
+
+  def test_render_passes_named_arguments_into_inner_scope
+    Liquid::Template.file_system = StubFileSystem.new('product' => '{{ inner_product.title }}')
+    assert_template_result 'My Product', '{% render "product", inner_product: outer_product %}',
+      'outer_product' => { 'title' => 'My Product' }
+  end
+
+  def test_render_accepts_literals_as_arguments
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ price }}')
+    assert_template_result '123', '{% render "snippet", price: 123 %}'
+  end
+
+  def test_render_accepts_multiple_named_arguments
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ one }} {{ two }}')
+    assert_template_result '1 2', '{% render "snippet", one: 1, two: 2 %}'
+  end
+
+  def test_render_does_not_inherit_parent_scope_variables
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ outer_variable }}')
+    assert_template_result '', '{% assign outer_variable = "should not be visible" %}{% render "snippet" %}'
+  end
+
+  def test_render_does_not_inherit_variable_with_same_name_as_snippet
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ snippet }}')
+    assert_template_result '', "{% assign snippet = 'should not be visible' %}{% render 'snippet' %}"
+  end
+
+  def test_render_sets_the_correct_template_name_for_errors
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ unsafe }}')
+
+    with_taint_mode :error do
+      template = Liquid::Template.parse('{% render "snippet", unsafe: unsafe %}')
+      context = Context.new('unsafe' => (+'unsafe').tap(&:taint))
+      template.render(context)
+
+      assert_equal [Liquid::TaintedError], template.errors.map(&:class)
+      assert_equal 'snippet', template.errors.first.template_name
+    end
+  end
+
+  def test_render_sets_the_correct_template_name_for_warnings
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{{ unsafe }}')
+
+    with_taint_mode :warn do
+      template = Liquid::Template.parse('{% render "snippet", unsafe: unsafe %}')
+      context = Context.new('unsafe' => (+'unsafe').tap(&:taint))
+      template.render(context)
+
+      assert_equal [Liquid::TaintedError], context.warnings.map(&:class)
+      assert_equal 'snippet', context.warnings.first.template_name
+    end
+  end
+
+  def test_render_does_not_mutate_parent_scope
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => '{% assign inner = 1 %}')
+    assert_template_result '', "{% render 'snippet' %}{{ inner }}"
+  end
+
+  def test_nested_render_tag
+    Liquid::Template.file_system = StubFileSystem.new(
+      'one' => "one {% render 'two' %}",
+      'two' => 'two'
+    )
+    assert_template_result 'one two', "{% render 'one' %}"
+  end
+
+  def test_recursively_rendered_template_does_not_produce_endless_loop
+    Liquid::Template.file_system = StubFileSystem.new('loop' => '{% render "loop" %}')
+
+    assert_raises Liquid::StackLevelError do
+      Template.parse('{% render "loop" %}').render!
+    end
+  end
+
+  def test_sub_contexts_count_towards_the_same_recursion_limit
+    Liquid::Template.file_system = StubFileSystem.new(
+      'loop_render' => '{% render "loop_render" %}',
+    )
+    assert_raises Liquid::StackLevelError do
+      Template.parse('{% render "loop_render" %}').render!
+    end
+  end
+
+  def test_dynamically_choosen_templates_are_not_allowed
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => 'should not be rendered')
+
+    assert_raises Liquid::SyntaxError do
+      Liquid::Template.parse("{% assign name = 'snippet' %}{% render name %}")
+    end
+  end
+
+  def test_include_tag_caches_second_read_of_same_partial
+    file_system = StubFileSystem.new('snippet' => 'echo')
+    assert_equal 'echoecho',
+      Template.parse('{% render "snippet" %}{% render "snippet" %}')
+      .render!({}, registers: { file_system: file_system })
+    assert_equal 1, file_system.file_read_count
+  end
+
+  def test_render_tag_doesnt_cache_partials_across_renders
+    file_system = StubFileSystem.new('snippet' => 'my message')
+
+    assert_equal 'my message',
+      Template.parse('{% include "snippet" %}').render!({}, registers: { file_system: file_system })
+    assert_equal 1, file_system.file_read_count
+
+    assert_equal 'my message',
+      Template.parse('{% include "snippet" %}').render!({}, registers: { file_system: file_system })
+    assert_equal 2, file_system.file_read_count
+  end
+
+  def test_render_tag_within_if_statement
+    Liquid::Template.file_system = StubFileSystem.new('snippet' => 'my message')
+    assert_template_result 'my message', '{% if true %}{% render "snippet" %}{% endif %}'
+  end
+
+  def test_break_through_render
+    Liquid::Template.file_system = StubFileSystem.new('break' => '{% break %}')
+    assert_template_result '1', '{% for i in (1..3) %}{{ i }}{% break %}{{ i }}{% endfor %}'
+    assert_template_result '112233', '{% for i in (1..3) %}{{ i }}{% render "break" %}{{ i }}{% endfor %}'
+  end
+
+  def test_increment_is_isolated_between_renders
+    Liquid::Template.file_system = StubFileSystem.new('incr' => '{% increment %}')
+    assert_template_result '010', '{% increment %}{% increment %}{% render "incr" %}'
+  end
+
+  def test_decrement_is_isolated_between_renders
+    Liquid::Template.file_system = StubFileSystem.new('decr' => '{% decrement %}')
+    assert_template_result '-1-2-1', '{% decrement %}{% decrement %}{% render "decr" %}'
+  end
+
+  def test_includes_will_not_render_inside_render_tag
+    Liquid::Template.file_system = StubFileSystem.new(
+      'foo' => 'bar',
+      'test_include' => '{% include "foo" %}'
+    )
+
+    assert_template_result 'include usage is not allowed in this context', '{% render "test_include" %}'
+  end
+
+  def test_includes_will_not_render_inside_nested_sibling_tags
+    Liquid::Template.file_system = StubFileSystem.new(
+      'foo' => 'bar',
+      'nested_render_with_sibling_include' => '{% render "test_include" %}{% include "foo" %}',
+      '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" %}'
+  end
+end

test/integration/tags/standard_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class StandardTagTest < Minitest::Test
@@ -69,7 +71,7 @@ class StandardTagTest < Minitest::Test
     assert_raises(SyntaxError) do
       assert_template_result('content foo content foo ',
         '{{ var2 }}{% capture %}{{ var }} foo {% endcapture %}{{ var2 }}{{ var2 }}',
-        { 'var' => 'content' })
+        'var' => 'content')
     end
   end
 
@@ -183,32 +185,32 @@ class StandardTagTest < Minitest::Test
 
   def test_case_when_or
     code = '{% case condition %}{% when 1 or 2 or 3 %} its 1 or 2 or 3 {% when 4 %} its 4 {% endcase %}'
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 1 })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 2 })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 3 })
-    assert_template_result(' its 4 ', code, { 'condition' => 4 })
-    assert_template_result('', code, { 'condition' => 5 })
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 1)
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 2)
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 3)
+    assert_template_result(' its 4 ', code, 'condition' => 4)
+    assert_template_result('', code, 'condition' => 5)
 
     code = '{% case condition %}{% when 1 or "string" or null %} its 1 or 2 or 3 {% when 4 %} its 4 {% endcase %}'
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 1 })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 'string' })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => nil })
-    assert_template_result('', code, { 'condition' => 'something else' })
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 1)
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 'string')
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => nil)
+    assert_template_result('', code, 'condition' => 'something else')
   end
 
   def test_case_when_comma
     code = '{% case condition %}{% when 1, 2, 3 %} its 1 or 2 or 3 {% when 4 %} its 4 {% endcase %}'
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 1 })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 2 })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 3 })
-    assert_template_result(' its 4 ', code, { 'condition' => 4 })
-    assert_template_result('', code, { 'condition' => 5 })
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 1)
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 2)
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 3)
+    assert_template_result(' its 4 ', code, 'condition' => 4)
+    assert_template_result('', code, 'condition' => 5)
 
     code = '{% case condition %}{% when 1, "string", null %} its 1 or 2 or 3 {% when 4 %} its 4 {% endcase %}'
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 1 })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => 'string' })
-    assert_template_result(' its 1 or 2 or 3 ', code, { 'condition' => nil })
-    assert_template_result('', code, { 'condition' => 'something else' })
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 1)
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => 'string')
+    assert_template_result(' its 1 or 2 or 3 ', code, 'condition' => nil)
+    assert_template_result('', code, 'condition' => 'something else')
   end
 
   def test_assign
@@ -283,10 +285,10 @@ class StandardTagTest < Minitest::Test
   end
 
   def test_ifchanged
-    assigns = { 'array' => [ 1, 1, 2, 2, 3, 3] }
+    assigns = { 'array' => [1, 1, 2, 2, 3, 3] }
     assert_template_result('123', '{%for item in array%}{%ifchanged%}{{item}}{% endifchanged %}{%endfor%}', assigns)
 
-    assigns = { 'array' => [ 1, 1, 1, 1] }
+    assigns = { 'array' => [1, 1, 1, 1] }
     assert_template_result('1', '{%for item in array%}{%ifchanged%}{{item}}{% endifchanged %}{%endfor%}', assigns)
   end
 

test/integration/tags/statements_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class StatementsTest < Minitest::Test

test/integration/tags/table_row_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TableRowTest < Minitest::Test

test/integration/tags/unless_else_tag_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class UnlessElseTagTest < Minitest::Test

test/integration/template_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 require 'timeout'
 
@@ -79,7 +81,10 @@ class TemplateTest < Minitest::Test
 
   def test_lambda_is_called_once_from_persistent_assigns_over_multiple_parses_and_renders
     t = Template.new
-    t.assigns['number'] = -> { @global ||= 0; @global += 1 }
+    t.assigns['number'] = -> {
+      @global ||= 0
+      @global += 1
+    }
     assert_equal '1', t.parse("{{number}}").render!
     assert_equal '1', t.parse("{{number}}").render!
     assert_equal '1', t.render!
@@ -88,7 +93,10 @@ class TemplateTest < Minitest::Test
 
   def test_lambda_is_called_once_from_custom_assigns_over_multiple_parses_and_renders
     t = Template.new
-    assigns = { 'number' => -> { @global ||= 0; @global += 1 } }
+    assigns = { 'number' => -> {
+                              @global ||= 0
+                              @global += 1
+                            } }
     assert_equal '1', t.parse("{{number}}").render!(assigns)
     assert_equal '1', t.parse("{{number}}").render!(assigns)
     assert_equal '1', t.render!(assigns)
@@ -139,6 +147,16 @@ class TemplateTest < Minitest::Test
     refute_nil t.resource_limits.assign_score
   end
 
+  def test_resource_limits_assign_score_counts_bytes_not_characters
+    t = Template.parse("{% assign foo = 'すごい' %}")
+    t.render
+    assert_equal 9, t.resource_limits.assign_score
+
+    t = Template.parse("{% capture foo %}すごい{% endcapture %}")
+    t.render
+    assert_equal 9, t.resource_limits.assign_score
+  end
+
   def test_resource_limits_assign_score_nested
     t = Template.parse("{% assign foo = 'aaaa' | reverse %}")
 
@@ -187,6 +205,14 @@ class TemplateTest < Minitest::Test
     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
+    assert_equal "Liquid error: Memory limits exceeded", t.render
+    t.resource_limits.render_length_limit = 18
+    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 %}")
@@ -206,7 +232,7 @@ class TemplateTest < Minitest::Test
   end
 
   def test_render_bang_force_rethrow_errors_on_passed_context
-    context = Context.new({ 'drop' => ErroneousDrop.new })
+    context = Context.new('drop' => ErroneousDrop.new)
     t = Template.new.parse('{{ drop.bad_method }}')
 
     e = assert_raises RuntimeError do
@@ -217,7 +243,10 @@ class TemplateTest < Minitest::Test
 
   def test_exception_renderer_that_returns_string
     exception = nil
-    handler = ->(e) { exception = e; '<!-- error -->' }
+    handler = ->(e) {
+      exception = e
+      '<!-- error -->'
+    }
 
     output = Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: handler)
 
@@ -228,7 +257,10 @@ class TemplateTest < Minitest::Test
   def test_exception_renderer_that_raises
     exception = nil
     assert_raises(Liquid::ZeroDivisionError) do
-      Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: ->(e) { exception = e; raise })
+      Template.parse("{{ 1 | divided_by: 0 }}").render({}, exception_renderer: ->(e) {
+                                                                                 exception = e
+                                                                                 raise
+                                                                               })
     end
     assert exception.is_a?(Liquid::ZeroDivisionError)
   end
@@ -249,7 +281,7 @@ class TemplateTest < Minitest::Test
 
   def test_undefined_variables
     t = Template.parse("{{x}} {{y}} {{z.a}} {{z.b}} {{z.c.d}}")
-    result = t.render({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, { strict_variables: true })
+    result = t.render({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, strict_variables: true)
 
     assert_equal '33  32  ', result
     assert_equal 3, t.errors.count
@@ -274,14 +306,14 @@ class TemplateTest < Minitest::Test
     t = Template.parse("{{x}} {{y}} {{z.a}} {{z.b}} {{z.c.d}}")
 
     assert_raises UndefinedVariable do
-      t.render!({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, { strict_variables: true })
+      t.render!({ 'x' => 33, 'z' => { 'a' => 32, 'c' => { 'e' => 31 } } }, strict_variables: true)
     end
   end
 
   def test_undefined_drop_methods
     d = DropWithUndefinedMethod.new
     t = Template.new.parse('{{ foo }} {{ woot }}')
-    result = t.render(d, { strict_variables: true })
+    result = t.render(d, strict_variables: true)
 
     assert_equal 'foo ', result
     assert_equal 1, t.errors.count
@@ -293,7 +325,7 @@ class TemplateTest < Minitest::Test
     t = Template.new.parse('{{ foo }} {{ woot }}')
 
     assert_raises UndefinedDropMethod do
-      t.render!(d, { strict_variables: true })
+      t.render!(d, strict_variables: true)
     end
   end
 
@@ -304,7 +336,7 @@ class TemplateTest < Minitest::Test
         "-#{v}-"
       end
     end
-    result = t.render({ 'a' => 123, 'x' => 'foo' }, { filters: [filters], strict_filters: true })
+    result = t.render({ 'a' => 123, 'x' => 'foo' }, filters: [filters], strict_filters: true)
 
     assert_equal '123 ', result
     assert_equal 1, t.errors.count
@@ -316,17 +348,17 @@ class TemplateTest < Minitest::Test
     t = Template.parse("{{x | somefilter1 | upcase | somefilter2}}")
 
     assert_raises UndefinedFilter do
-      t.render!({ 'x' => 'foo' }, { strict_filters: true })
+      t.render!({ 'x' => 'foo' }, strict_filters: true)
     end
   end
 
   def test_using_range_literal_works_as_expected
     t = Template.parse("{% assign foo = (x..y) %}{{ foo }}")
-    result = t.render({ 'x' => 1, 'y' => 5 })
+    result = t.render('x' => 1, 'y' => 5)
     assert_equal '1..5', result
 
     t = Template.parse("{% assign nums = (x..y) %}{% for num in nums %}{{ num }}{% endfor %}")
-    result = t.render({ 'x' => 1, 'y' => 5 })
+    result = t.render('x' => 1, 'y' => 5)
     assert_equal '12345', result
   end
 end

test/integration/trim_mode_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TrimModeTest < Minitest::Test
@@ -76,14 +78,14 @@ class TrimModeTest < Minitest::Test
         </p>
       </div>
     END_TEMPLATE
-    expected = <<-END_EXPECTED
-      <div>
-        <p>
-#{whitespace}
-          yes
-#{whitespace}
-        </p>
-      </div>
+    expected = <<~END_EXPECTED
+            <div>
+              <p>
+      #{whitespace}
+                yes
+      #{whitespace}
+              </p>
+            </div>
     END_EXPECTED
     assert_template_result(expected, text)
 
@@ -96,12 +98,12 @@ class TrimModeTest < Minitest::Test
         </p>
       </div>
     END_TEMPLATE
-    expected = <<-END_EXPECTED
-      <div>
-        <p>
-#{whitespace}
-        </p>
-      </div>
+    expected = <<~END_EXPECTED
+            <div>
+              <p>
+      #{whitespace}
+              </p>
+            </div>
     END_EXPECTED
     assert_template_result(expected, text)
   end
@@ -337,12 +339,12 @@ class TrimModeTest < Minitest::Test
         </p>
       </div>
     END_TEMPLATE
-    expected = <<-END_EXPECTED
-      <div>
-        <p>
-#{whitespace}
-        </p>
-      </div>
+    expected = <<~END_EXPECTED
+            <div>
+              <p>
+      #{whitespace}
+              </p>
+            </div>
     END_EXPECTED
     assert_template_result(expected, text)
   end
@@ -513,16 +515,16 @@ class TrimModeTest < Minitest::Test
         {% endraw %}
       </div>
     END_TEMPLATE
-    expected = <<-END_EXPECTED
-      <div>
-#{whitespace}
-          {%- if true -%}
-            <p>
-              {{- 'John' -}}
-            </p>
-          {%- endif -%}
-#{whitespace}
-      </div>
+    expected = <<~END_EXPECTED
+            <div>
+      #{whitespace}
+                {%- if true -%}
+                  <p>
+                    {{- 'John' -}}
+                  </p>
+                {%- endif -%}
+      #{whitespace}
+            </div>
     END_EXPECTED
     assert_template_result(expected, text)
   end

test/integration/variable_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class VariableTest < Minitest::Test
@@ -76,7 +78,7 @@ class VariableTest < Minitest::Test
 
   def test_hash_with_default_proc
     template = Template.parse(%(Hello {{ test }}))
-    assigns = Hash.new { |h, k| raise "Unknown variable '#{k}'" }
+    assigns = Hash.new { |_h, k| raise "Unknown variable '#{k}'" }
     assigns['test'] = 'Tobi'
     assert_equal 'Hello Tobi', template.render!(assigns)
     assigns.delete('test')

test/test_helper.rb

@@ -1,4 +1,5 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
 
 ENV["MT_NO_EXPECTATIONS"] = "1"
 require 'minitest/autorun'
@@ -8,13 +9,13 @@ require 'liquid.rb'
 require 'liquid/profiler'
 
 mode = :strict
-if env_mode = ENV['LIQUID_PARSER_MODE']
+if (env_mode = ENV['LIQUID_PARSER_MODE'])
   puts "-- #{env_mode.upcase} ERROR MODE"
   mode = env_mode.to_sym
 end
 Liquid::Template.error_mode = mode
 
-if ENV['LIQUID-C'] == '1'
+if ENV['LIQUID_C'] == '1'
   puts "-- LIQUID C"
   require 'liquid/c'
 end
@@ -37,18 +38,18 @@ module Minitest
     include Liquid
 
     def assert_template_result(expected, template, assigns = {}, message = nil)
-      assert_equal expected, Template.parse(template).render!(assigns), message
+      assert_equal expected, Template.parse(template, line_numbers: true).render!(assigns), message
     end
 
     def assert_template_result_matches(expected, template, assigns = {}, message = nil)
-      return assert_template_result(expected, template, assigns, message) unless expected.is_a? Regexp
+      return assert_template_result(expected, template, assigns, message) unless expected.is_a?(Regexp)
 
-      assert_match expected, Template.parse(template).render!(assigns), message
+      assert_match expected, Template.parse(template, line_numbers: true).render!(assigns), message
     end
 
     def assert_match_syntax_error(match, template, assigns = {})
       exception = assert_raises(Liquid::SyntaxError) do
-        Template.parse(template).render(assigns)
+        Template.parse(template, line_numbers: true).render(assigns)
       end
       assert_match match, exception.message
     end
@@ -84,6 +85,13 @@ module Minitest
     ensure
       Liquid::Template.error_mode = old_mode
     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)
+    end
   end
 end
 
@@ -114,3 +122,17 @@ class ErrorDrop < Liquid::Drop
     raise Exception, 'exception'
   end
 end
+
+class StubFileSystem
+  attr_reader :file_read_count
+
+  def initialize(values)
+    @file_read_count = 0
+    @values = values
+  end
+
+  def read_template_file(template_path)
+    @file_read_count += 1
+    @values.fetch(template_path)
+  end
+end

test/unit/block_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class BlockUnitTest < Minitest::Test
@@ -44,10 +46,47 @@ class BlockUnitTest < Minitest::Test
   end
 
   def test_with_custom_tag
-    Liquid::Template.register_tag("testtag", Block)
-    assert Liquid::Template.parse("{% testtag %} {% endtesttag %}")
-  ensure
-    Liquid::Template.tags.delete('testtag')
+    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

test/unit/condition_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ConditionUnitTest < Minitest::Test
@@ -24,9 +26,9 @@ class ConditionUnitTest < Minitest::Test
     assert_evaluates_true 1, '<=', 1
     # negative numbers
     assert_evaluates_true 1, '>', -1
-    assert_evaluates_true (-1), '<', 1
+    assert_evaluates_true(-1, '<', 1)
     assert_evaluates_true 1.0, '>', -1.0
-    assert_evaluates_true (-1.0), '<', 1.0
+    assert_evaluates_true(-1.0, '<', 1.0)
   end
 
   def test_default_operators_evalute_false
@@ -68,7 +70,7 @@ class ConditionUnitTest < Minitest::Test
     assert_nil Condition.new({}, '>', 2).evaluate
     assert_nil Condition.new(2, '>', {}).evaluate
     assert_equal false, Condition.new({}, '==', 2).evaluate
-    assert_equal true, Condition.new({ 'a' => 1 }, '==', { 'a' => 1 }).evaluate
+    assert_equal true, Condition.new({ 'a' => 1 }, '==', 'a' => 1).evaluate
     assert_equal true, Condition.new({ 'a' => 2 }, 'contains', 'a').evaluate
   end
 
@@ -107,11 +109,11 @@ class ConditionUnitTest < Minitest::Test
 
     assert_equal false, condition.evaluate
 
-    condition.or Condition.new(2, '==', 1)
+    condition.or(Condition.new(2, '==', 1))
 
     assert_equal false, condition.evaluate
 
-    condition.or Condition.new(1, '==', 1)
+    condition.or(Condition.new(1, '==', 1))
 
     assert_equal true, condition.evaluate
   end
@@ -121,22 +123,22 @@ class ConditionUnitTest < Minitest::Test
 
     assert_equal true, condition.evaluate
 
-    condition.and Condition.new(2, '==', 2)
+    condition.and(Condition.new(2, '==', 2))
 
     assert_equal true, condition.evaluate
 
-    condition.and Condition.new(2, '==', 1)
+    condition.and(Condition.new(2, '==', 1))
 
     assert_equal false, condition.evaluate
   end
 
   def test_should_allow_custom_proc_operator
-    Condition.operators['starts_with'] = proc { |cond, left, right| left =~ %r{^#{right}} }
+    Condition.operators['starts_with'] = proc { |_cond, left, right| left =~ /^#{right}/ }
 
     assert_evaluates_true 'bob', 'starts_with', 'b'
     assert_evaluates_false 'bob', 'starts_with', 'o'
   ensure
-    Condition.operators.delete 'starts_with'
+    Condition.operators.delete('starts_with')
   end
 
   def test_left_or_right_may_contain_operators

test/unit/context_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class HundredCentes
@@ -83,7 +85,7 @@ class ContextUnitTest < Minitest::Test
     @context['date'] = Date.today
     assert_equal Date.today, @context['date']
 
-    now = DateTime.now
+    now = Time.now
     @context['datetime'] = now
     assert_equal now, @context['datetime']
 
@@ -206,9 +208,9 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_merge
-    @context.merge({ "test" => "test" })
+    @context.merge("test" => "test")
     assert_equal 'test', @context['test']
-    @context.merge({ "test" => "newvalue", "foo" => "bar" })
+    @context.merge("test" => "newvalue", "foo" => "bar")
     assert_equal 'newvalue', @context['test']
     assert_equal 'bar', @context['foo']
   end
@@ -235,10 +237,10 @@ class ContextUnitTest < Minitest::Test
 
   def test_hash_to_array_transition
     @context['colors'] = {
-      'Blue'    => ['003366', '336699', '6699CC', '99CCFF'],
-      'Green'   => ['003300', '336633', '669966', '99CC99'],
-      'Yellow'  => ['CC9900', 'FFCC00', 'FFFF99', 'FFFFCC'],
-      'Red'     => ['660000', '993333', 'CC6666', 'FF9999']
+      'Blue' => ['003366', '336699', '6699CC', '99CCFF'],
+      'Green' => ['003300', '336633', '669966', '99CC99'],
+      'Yellow' => ['CC9900', 'FFCC00', 'FFFF99', 'FFFFCC'],
+      'Red' => ['660000', '993333', 'CC6666', 'FF9999'],
     }
 
     assert_equal '003366', @context['colors.Blue[0]']
@@ -263,7 +265,7 @@ class ContextUnitTest < Minitest::Test
 
   def test_access_hashes_with_hash_notation
     @context['products'] = { 'count' => 5, 'tags' => ['deepsnow', 'freestyle'] }
-    @context['product'] = { 'variants' => [ { 'title' => 'draft151cm' }, { 'title' => 'element151cm' } ] }
+    @context['product'] = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
 
     assert_equal 5, @context['products["count"]']
     assert_equal 'deepsnow', @context['products["tags"][0]']
@@ -301,7 +303,7 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_first_can_appear_in_middle_of_callchain
-    @context['product'] = { 'variants' => [ { 'title' => 'draft151cm' }, { 'title' => 'element151cm' } ] }
+    @context['product'] = { 'variants' => [{ 'title' => 'draft151cm' }, { 'title' => 'element151cm' }] }
 
     assert_equal 'draft151cm', @context['product.variants[0].title']
     assert_equal 'element151cm', @context['product.variants[1].title']
@@ -403,7 +405,11 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_lambda_is_called_once
-    @context['callcount'] = proc { @global ||= 0; @global += 1; @global.to_s }
+    @context['callcount'] = proc {
+      @global ||= 0
+      @global += 1
+      @global.to_s
+    }
 
     assert_equal '1', @context['callcount']
     assert_equal '1', @context['callcount']
@@ -413,7 +419,11 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_nested_lambda_is_called_once
-    @context['callcount'] = { "lambda" => proc { @global ||= 0; @global += 1; @global.to_s } }
+    @context['callcount'] = { "lambda" => proc {
+                                            @global ||= 0
+                                            @global += 1
+                                            @global.to_s
+                                          } }
 
     assert_equal '1', @context['callcount.lambda']
     assert_equal '1', @context['callcount.lambda']
@@ -423,7 +433,11 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_lambda_in_array_is_called_once
-    @context['callcount'] = [1, 2, proc { @global ||= 0; @global += 1; @global.to_s }, 4, 5]
+    @context['callcount'] = [1, 2, proc {
+                                     @global ||= 0
+                                     @global += 1
+                                     @global.to_s
+                                   }, 4, 5]
 
     assert_equal '1', @context['callcount[2]']
     assert_equal '1', @context['callcount[2]']
@@ -453,7 +467,7 @@ class ContextUnitTest < Minitest::Test
   end
 
   def test_context_initialization_with_a_proc_in_environment
-    contx = Context.new([test: ->(c) { c['poutine'] }], { test: :foo })
+    contx = Context.new([test: ->(c) { c['poutine'] }], test: :foo)
 
     assert contx
     assert_nil contx['poutine']
@@ -468,11 +482,87 @@ class ContextUnitTest < Minitest::Test
     assert_equal 'hi filtered', context.apply_global_filter('hi')
   end
 
+  def test_static_environments_are_read_with_lower_priority_than_environments
+    context = Context.build(
+      static_environments: { 'shadowed' => 'static', 'unshadowed' => 'static' },
+      environments: { 'shadowed' => 'dynamic' }
+    )
+
+    assert_equal 'dynamic', context['shadowed']
+    assert_equal 'static', context['unshadowed']
+  end
+
   def test_apply_global_filter_when_no_global_filter_exist
     context = Context.new
     assert_equal 'hi', context.apply_global_filter('hi')
   end
 
+  def test_new_isolated_subcontext_does_not_inherit_variables
+    super_context = Context.new
+    super_context['my_variable'] = 'some value'
+    subcontext = super_context.new_isolated_subcontext
+
+    assert_nil subcontext['my_variable']
+  end
+
+  def test_new_isolated_subcontext_inherits_static_environment
+    super_context = Context.build(static_environments: { 'my_environment_value' => 'my value' })
+    subcontext = super_context.new_isolated_subcontext
+
+    assert_equal 'my value', subcontext['my_environment_value']
+  end
+
+  def test_new_isolated_subcontext_inherits_resource_limits
+    resource_limits = ResourceLimits.new({})
+    super_context = Context.new({}, {}, {}, false, resource_limits)
+    subcontext = super_context.new_isolated_subcontext
+    assert_equal resource_limits, subcontext.resource_limits
+  end
+
+  def test_new_isolated_subcontext_inherits_exception_renderer
+    super_context = Context.new
+    super_context.exception_renderer = ->(_e) { 'my exception message' }
+    subcontext = super_context.new_isolated_subcontext
+    assert_equal 'my exception message', subcontext.handle_error(Liquid::Error.new)
+  end
+
+  def test_new_isolated_subcontext_does_not_inherit_non_static_registers
+    registers = {
+      my_register: :my_value,
+    }
+    super_context = Context.new({}, {}, StaticRegisters.new(registers))
+    super_context.registers[:my_register] = :my_alt_value
+    subcontext = super_context.new_isolated_subcontext
+    assert_equal :my_value, subcontext.registers[:my_register]
+  end
+
+  def test_new_isolated_subcontext_inherits_static_registers
+    super_context = Context.build(registers: { my_register: :my_value })
+    subcontext = super_context.new_isolated_subcontext
+    assert_equal :my_value, subcontext.registers[:my_register]
+  end
+
+  def test_new_isolated_subcontext_registers_do_not_pollute_context
+    super_context = Context.build(registers: { my_register: :my_value })
+    subcontext = super_context.new_isolated_subcontext
+    subcontext.registers[:my_register] = :my_alt_value
+    assert_equal :my_value, super_context.registers[:my_register]
+  end
+
+  def test_new_isolated_subcontext_inherits_filters
+    my_filter = Module.new do
+      def my_filter(*)
+        'my filter result'
+      end
+    end
+
+    super_context = Context.new
+    super_context.add_filters([my_filter])
+    subcontext = super_context.new_isolated_subcontext
+    template = Template.parse('{{ 123 | my_filter }}')
+    assert_equal 'my filter result', template.render(subcontext)
+  end
+
   private
 
   def assert_no_object_allocations

test/unit/file_system_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class FileSystemUnitTest < Minitest::Test

test/unit/i18n_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class I18nUnitTest < Minitest::Test

test/unit/lexer_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class LexerUnitTest < Minitest::Test

test/unit/parser_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ParserUnitTest < Minitest::Test

test/unit/partial_cache_unit_test.rb

@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class PartialCacheUnitTest < Minitest::Test
+  def test_uses_the_file_system_register_if_present
+    context = Liquid::Context.build(
+      registers: {
+        file_system: StubFileSystem.new('my_partial' => 'my partial body'),
+      }
+    )
+
+    partial = Liquid::PartialCache.load(
+      'my_partial',
+      context: context,
+      parse_context: Liquid::ParseContext.new
+    )
+
+    assert_equal 'my partial body', partial.render
+  end
+
+  def test_reads_from_the_file_system_only_once_per_file
+    file_system = StubFileSystem.new('my_partial' => 'some partial body')
+    context = Liquid::Context.build(
+      registers: { file_system: file_system }
+    )
+
+    2.times do
+      Liquid::PartialCache.load(
+        'my_partial',
+        context: context,
+        parse_context: Liquid::ParseContext.new
+      )
+    end
+
+    assert_equal 1, file_system.file_read_count
+  end
+
+  def test_cache_state_is_stored_per_context
+    parse_context = Liquid::ParseContext.new
+    shared_file_system = StubFileSystem.new(
+      'my_partial' => 'my shared value'
+    )
+    context_one = Liquid::Context.build(
+      registers: {
+        file_system: shared_file_system,
+      }
+    )
+    context_two = Liquid::Context.build(
+      registers: {
+        file_system: shared_file_system,
+      }
+    )
+
+    2.times do
+      Liquid::PartialCache.load(
+        'my_partial',
+        context: context_one,
+        parse_context: parse_context
+      )
+    end
+
+    Liquid::PartialCache.load(
+      'my_partial',
+      context: context_two,
+      parse_context: parse_context
+    )
+
+    assert_equal 2, shared_file_system.file_read_count
+  end
+
+  def test_cache_is_not_broken_when_a_different_parse_context_is_used
+    file_system = StubFileSystem.new('my_partial' => 'some partial body')
+    context = Liquid::Context.build(
+      registers: { file_system: file_system }
+    )
+
+    Liquid::PartialCache.load(
+      'my_partial',
+      context: context,
+      parse_context: Liquid::ParseContext.new(my_key: 'value one')
+    )
+    Liquid::PartialCache.load(
+      'my_partial',
+      context: context,
+      parse_context: Liquid::ParseContext.new(my_key: 'value two')
+    )
+
+    # Technically what we care about is that the file was parsed twice,
+    # but measuring file reads is an OK proxy for this.
+    assert_equal 1, file_system.file_read_count
+  end
+end

test/unit/regexp_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class RegexpUnitTest < Minitest::Test

test/unit/registers/disabled_tags_unit_test.rb

@@ -0,0 +1,36 @@
+# 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

test/unit/static_registers_unit_test.rb

@@ -0,0 +1,248 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class StaticRegistersUnitTest < Minitest::Test
+  include Liquid
+
+  def set
+    static_register = StaticRegisters.new
+    static_register[nil] = true
+    static_register[1] = :one
+    static_register[:one] = "one"
+    static_register["two"] = "three"
+    static_register["two"] = 3
+    static_register[false] = nil
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.registers)
+
+    static_register
+  end
+
+  def test_get
+    static_register = set
+
+    assert_equal true, static_register[nil]
+    assert_equal :one, static_register[1]
+    assert_equal "one", static_register[:one]
+    assert_equal 3, static_register["two"]
+    assert_nil static_register[false]
+    assert_nil static_register["unknown"]
+  end
+
+  def test_delete
+    static_register = set
+
+    assert_equal true, static_register.delete(nil)
+    assert_equal :one, static_register.delete(1)
+    assert_equal "one", static_register.delete(:one)
+    assert_equal 3, static_register.delete("two")
+    assert_nil static_register.delete(false)
+    assert_nil static_register.delete("unknown")
+
+    assert_equal({}, static_register.registers)
+  end
+
+  def test_fetch
+    static_register = set
+
+    assert_equal true, static_register.fetch(nil)
+    assert_equal :one, static_register.fetch(1)
+    assert_equal "one", static_register.fetch(:one)
+    assert_equal 3, static_register.fetch("two")
+    assert_nil static_register.fetch(false)
+    assert_nil static_register.fetch("unknown")
+  end
+
+  def test_fetch_default
+    static_register = StaticRegisters.new
+
+    assert_equal true, static_register.fetch(nil, true)
+    assert_equal :one, static_register.fetch(1, :one)
+    assert_equal "one", static_register.fetch(:one, "one")
+    assert_equal 3, static_register.fetch("two", 3)
+    assert_nil static_register.fetch(false, nil)
+  end
+
+  def test_key
+    static_register = set
+
+    assert_equal true, static_register.key?(nil)
+    assert_equal true, static_register.key?(1)
+    assert_equal true, static_register.key?(:one)
+    assert_equal true, static_register.key?("two")
+    assert_equal true, static_register.key?(false)
+    assert_equal false, static_register.key?("unknown")
+    assert_equal false, static_register.key?(true)
+  end
+
+  def set_with_static
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register[nil] = false
+    static_register["two"] = 4
+    static_register[true] = "foo"
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+    assert_equal({ nil => false, "two" => 4, true => "foo" }, static_register.registers)
+
+    static_register
+  end
+
+  def test_get_with_static
+    static_register = set_with_static
+
+    assert_equal false, static_register[nil]
+    assert_equal :one, static_register[1]
+    assert_equal "one", static_register[:one]
+    assert_equal 4, static_register["two"]
+    assert_equal "foo", static_register[true]
+    assert_nil static_register[false]
+  end
+
+  def test_delete_with_static
+    static_register = set_with_static
+
+    assert_equal false, static_register.delete(nil)
+    assert_equal 4, static_register.delete("two")
+    assert_equal "foo", static_register.delete(true)
+    assert_nil static_register.delete("unknown")
+    assert_nil static_register.delete(:one)
+
+    assert_equal({}, static_register.registers)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+  end
+
+  def test_fetch_with_static
+    static_register = set_with_static
+
+    assert_equal false, static_register.fetch(nil)
+    assert_equal :one, static_register.fetch(1)
+    assert_equal "one", static_register.fetch(:one)
+    assert_equal 4, static_register.fetch("two")
+    assert_equal "foo", static_register.fetch(true)
+    assert_nil static_register.fetch(false)
+  end
+
+  def test_key_with_static
+    static_register = set_with_static
+
+    assert_equal true, static_register.key?(nil)
+    assert_equal true, static_register.key?(1)
+    assert_equal true, static_register.key?(:one)
+    assert_equal true, static_register.key?("two")
+    assert_equal true, static_register.key?(false)
+    assert_equal false, static_register.key?("unknown")
+    assert_equal true, static_register.key?(true)
+  end
+
+  def test_static_register_can_be_frozen
+    static_register = set_with_static
+
+    static = static_register.static.freeze
+
+    assert_raises(RuntimeError) do
+      static["two"] = "foo"
+    end
+
+    assert_raises(RuntimeError) do
+      static["unknown"] = "foo"
+    end
+
+    assert_raises(RuntimeError) do
+      static.delete("two")
+    end
+  end
+
+  def test_new_static_retains_static
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register["one"] = 1
+    static_register["two"] = 2
+    static_register["three"] = 3
+
+    new_register = StaticRegisters.new(static_register)
+    assert_equal({}, new_register.registers)
+
+    new_register["one"] = 4
+    new_register["two"] = 5
+    new_register["three"] = 6
+
+    newest_register = StaticRegisters.new(new_register)
+    assert_equal({}, newest_register.registers)
+
+    newest_register["one"] = 7
+    newest_register["two"] = 8
+    newest_register["three"] = 9
+
+    assert_equal({ "one" => 1, "two" => 2, "three" => 3 }, static_register.registers)
+    assert_equal({ "one" => 4, "two" => 5, "three" => 6 }, new_register.registers)
+    assert_equal({ "one" => 7, "two" => 8, "three" => 9 }, newest_register.registers)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, new_register.static)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, newest_register.static)
+  end
+
+  def test_multiple_instances_are_unique
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register["one"] = 1
+    static_register["two"] = 2
+    static_register["three"] = 3
+
+    new_register = StaticRegisters.new(foo: :bar)
+    assert_equal({}, new_register.registers)
+
+    new_register["one"] = 4
+    new_register["two"] = 5
+    new_register["three"] = 6
+
+    newest_register = StaticRegisters.new(bar: :foo)
+    assert_equal({}, newest_register.registers)
+
+    newest_register["one"] = 7
+    newest_register["two"] = 8
+    newest_register["three"] = 9
+
+    assert_equal({ "one" => 1, "two" => 2, "three" => 3 }, static_register.registers)
+    assert_equal({ "one" => 4, "two" => 5, "three" => 6 }, new_register.registers)
+    assert_equal({ "one" => 7, "two" => 8, "three" => 9 }, newest_register.registers)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+    assert_equal({ foo: :bar }, new_register.static)
+    assert_equal({ bar: :foo }, newest_register.static)
+  end
+
+  def test_can_update_static_directly_and_updates_all_instances
+    static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
+    static_register["one"] = 1
+    static_register["two"] = 2
+    static_register["three"] = 3
+
+    new_register = StaticRegisters.new(static_register)
+    assert_equal({}, new_register.registers)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil }, static_register.static)
+
+    new_register["one"] = 4
+    new_register["two"] = 5
+    new_register["three"] = 6
+    new_register.static["four"] = 10
+
+    newest_register = StaticRegisters.new(new_register)
+    assert_equal({}, newest_register.registers)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 10 }, new_register.static)
+
+    newest_register["one"] = 7
+    newest_register["two"] = 8
+    newest_register["three"] = 9
+    new_register.static["four"] = 5
+    new_register.static["five"] = 15
+
+    assert_equal({ "one" => 1, "two" => 2, "three" => 3 }, static_register.registers)
+    assert_equal({ "one" => 4, "two" => 5, "three" => 6 }, new_register.registers)
+    assert_equal({ "one" => 7, "two" => 8, "three" => 9 }, newest_register.registers)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 5, "five" => 15 }, newest_register.static)
+
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 5, "five" => 15 }, static_register.static)
+    assert_equal({ nil => true, 1 => :one, :one => "one", "two" => 3, false => nil, "four" => 5, "five" => 15 }, new_register.static)
+  end
+end

test/unit/strainer_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class StrainerUnitTest < Minitest::Test
@@ -36,7 +38,8 @@ class StrainerUnitTest < Minitest::Test
     rescue Liquid::ArgumentError => e
       assert_match(
         /\ALiquid error: wrong number of arguments \((1 for 0|given 1, expected 0)\)\z/,
-        e.message)
+        e.message
+      )
       assert_equal e.backtrace[0].split(':')[0], __FILE__
     end
   end
@@ -135,7 +138,7 @@ class StrainerUnitTest < Minitest::Test
   end
 
   module LateAddedFilter
-    def late_added_filter(input)
+    def late_added_filter(_input)
       "filtered"
     end
   end
@@ -150,7 +153,7 @@ class StrainerUnitTest < Minitest::Test
     mod = Module.new do
       class << self
         attr_accessor :include_count
-        def included(mod)
+        def included(_mod)
           self.include_count += 1
         end
       end

test/unit/tag_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TagUnitTest < Minitest::Test
@@ -18,4 +20,42 @@ 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

test/unit/tags/case_tag_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class CaseTagUnitTest < Minitest::Test

test/unit/tags/for_tag_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class ForTagUnitTest < Minitest::Test

test/unit/tags/if_tag_unit_test.rb

@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class IfTagUnitTest < Minitest::Test
   def test_if_nodelist
     template = Liquid::Template.parse('{% if true %}IF{% else %}ELSE{% endif %}')
-    assert_equal ['IF', 'ELSE'], template.root.nodelist[0].nodelist.map(&:nodelist).flatten
+    assert_equal(['IF', 'ELSE'], template.root.nodelist[0].nodelist.map(&:nodelist).flatten)
   end
 end

test/unit/template_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TemplateUnitTest < Minitest::Test

test/unit/tokenizer_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class TokenizerTest < Minitest::Test
@@ -33,7 +35,7 @@ class TokenizerTest < Minitest::Test
   def tokenize(source)
     tokenizer = Liquid::Tokenizer.new(source)
     tokens = []
-    while t = tokenizer.shift
+    while (t = tokenizer.shift)
       tokens << t
     end
     tokens

test/unit/variable_unit_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'test_helper'
 
 class VariableUnitTest < Minitest::Test