From 2a8b75ba5bec1fd6210ac64c92f0a3c9bccde3a0 Mon Sep 17 00:00:00 2001
From: Michael Go <michael.go@shopify.com>
Date: Thu, 14 Nov 2024 00:59:01 -0400
Subject: [PATCH] fix quirky negative sign expression markup parsing

---
 lib/liquid.rb                       |  2 +-
 lib/liquid/expression.rb            |  3 ++-
 test/integration/expression_test.rb | 14 +++++++++++++-
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/lib/liquid.rb b/lib/liquid.rb
index 0a970005d..367fc3c43 100644
--- a/lib/liquid.rb
+++ b/lib/liquid.rb
@@ -68,7 +68,6 @@ module Liquid
 require 'liquid/errors'
 require 'liquid/interrupts'
 require 'liquid/strainer_template'
-require 'liquid/expression'
 require 'liquid/context'
 require 'liquid/tag'
 require 'liquid/block_body'
@@ -77,6 +76,7 @@ module Liquid
 require 'liquid/variable_lookup'
 require 'liquid/range_lookup'
 require 'liquid/resource_limits'
+require 'liquid/expression'
 require 'liquid/template'
 require 'liquid/condition'
 require 'liquid/utils'
diff --git a/lib/liquid/expression.rb b/lib/liquid/expression.rb
index 22cc7227e..e10f97939 100644
--- a/lib/liquid/expression.rb
+++ b/lib/liquid/expression.rb
@@ -57,7 +57,8 @@ class Expression2
       'true' => true,
       'false' => false,
       'blank' => '',
-      'empty' => ''
+      'empty' => '',
+      '-' => VariableLookup.parse("-")
     }.freeze
 
     DOT = ".".ord
diff --git a/test/integration/expression_test.rb b/test/integration/expression_test.rb
index 7f451afd1..dc57ad286 100644
--- a/test/integration/expression_test.rb
+++ b/test/integration/expression_test.rb
@@ -23,7 +23,7 @@ def test_int
   end
 
   def test_float
-    assert_template_result("-17.42", "{{ -17.42  }}")
+    assert_template_result("-17.42", "{{ -17.42 }}")
     assert_template_result("2.5", "{{ 2.5 }}")
     assert_expression_result(1.5, "1.5")
   end
@@ -42,6 +42,18 @@ def test_range
     )
   end
 
+  def test_quirky_negative_sign_expression_markup
+    result = Expression.parse("-")
+    assert(result.is_a?(VariableLookup))
+    assert_equal("-", result.name)
+
+    # for this template, the expression markup is "-"
+    assert_template_result(
+      "",
+      "{{ - 'theme.css' - }}",
+    )
+  end
+
   private
 
   def assert_expression_result(expect, markup, **assigns)