From 0d5e3809b146b5cf624604595f5b0ebec5dfb469 Mon Sep 17 00:00:00 2001
From: Andrey Rahmatullin <wrar@wrar.name>
Date: Tue, 25 Oct 2022 15:30:25 +0500
Subject: [PATCH] Allow empty strings in asserts (#130)

---
 cssselect/xpath.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/cssselect/xpath.py b/cssselect/xpath.py
index 2d1ce37..f51cfb4 100644
--- a/cssselect/xpath.py
+++ b/cssselect/xpath.py
@@ -673,14 +673,14 @@ def xpath_attrib_exists(self, xpath: XPathExpr, name: str, value: Optional[str])
         return xpath
 
     def xpath_attrib_equals(self, xpath: XPathExpr, name: str, value: Optional[str]) -> XPathExpr:
-        assert value
+        assert value is not None
         xpath.add_condition("%s = %s" % (name, self.xpath_literal(value)))
         return xpath
 
     def xpath_attrib_different(
         self, xpath: XPathExpr, name: str, value: Optional[str]
     ) -> XPathExpr:
-        assert value
+        assert value is not None
         # FIXME: this seems like a weird hack...
         if value:
             xpath.add_condition("not(%s) or %s != %s" % (name, name, self.xpath_literal(value)))
@@ -703,7 +703,7 @@ def xpath_attrib_includes(
     def xpath_attrib_dashmatch(
         self, xpath: XPathExpr, name: str, value: Optional[str]
     ) -> XPathExpr:
-        assert value
+        assert value is not None
         # Weird, but true...
         xpath.add_condition(
             "%s and (%s = %s or starts-with(%s, %s))"