keywords are case sensitive

src/parse/value/parse.rs

@@ -311,7 +311,7 @@ impl<'a> Parser<'a> {
         }
 
         // check for keywords
-        Ok(match lower.as_str() {
+        Ok(match s.as_str() {
             "true" => IntermediateValue::Value(HigherIntermediateValue::Literal(Value::True)),
             "false" => IntermediateValue::Value(HigherIntermediateValue::Literal(Value::False)),
             "null" => IntermediateValue::Value(HigherIntermediateValue::Literal(Value::Null)),

tests/and.rs

@@ -46,7 +46,6 @@ test!(
     "a {\n  color: 1-and;\n}\n"
 );
 test!(
-    #[ignore = "casing is not preserved for keyword operators"]
     part_of_binop_casing,
     "a {\n  color: 1 - AND;\n}\n",
     "a {\n  color: 1-AND;\n}\n"

tests/extend.rs

@@ -1757,7 +1757,6 @@ test!(
     "@media screen {\n  a {\n    x: y;\n  }\n\n  @page {}\n}\n"
 );
 test!(
-    #[ignore = "to investigate"]
     escaped_selector,
     "// Escapes in selectors' identifiers should be normalized before `@extend` is
     // applied.

tests/null.rs

@@ -33,3 +33,8 @@ test!(
     "a {\n  $x: null;\n  color: -$x;\n}\n",
     "a {\n  color: -;\n}\n"
 );
+test!(
+    null_is_case_sensitive,
+    "a {\n  color: NULL;\n}\n",
+    "a {\n  color: NULL;\n}\n"
+);

tests/or.rs

@@ -54,7 +54,6 @@ test!(
     "a {\n  color: 1-or;\n}\n"
 );
 test!(
-    #[ignore = "casing is not preserved for keyword operators"]
     part_of_binop_casing,
     "a {\n  color: 1 - OR;\n}\n",
     "a {\n  color: 1-OR;\n}\n"