plain-css invert accepts numbers of any unit

src/builtin/functions/color/hsl.rs

@@ -1,5 +1,6 @@
 use super::{Builtin, GlobalFunctionMap};
 
+use codemap::Spanned;
 use num_traits::One;
 
 use crate::{
@@ -455,14 +456,18 @@ pub(crate) fn complement(mut args: CallArgs, parser: &mut Parser<'_>) -> SassRes
 
 pub(crate) fn invert(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value> {
     args.max_args(2)?;
-    let weight = match args.default_arg(
+    let weight = match args.get(1, "weight") {
-        1,
+        Some(Err(e)) => return Err(e),
-        "weight",
+        Some(Ok(Spanned {
-        Value::Dimension(Some(Number::from(100)), Unit::Percent, true),
+            node: Value::Dimension(Some(n), u, _),
-    )? {
+            ..
-        Value::Dimension(Some(n), u, _) => bound!(args, "weight", n, u, 0, 100) / Number::from(100),
+        })) => Some(bound!(args, "weight", n, u, 0, 100) / Number::from(100)),
-        Value::Dimension(None, ..) => todo!(),
+        Some(Ok(Spanned {
-        v => {
+            node: Value::Dimension(None, ..),
+            ..
+        })) => todo!(),
+        None => None,
+        Some(Ok(v)) => {
             return Err((
                 format!(
                     "$weight: {} is not a number.",
@@ -474,16 +479,24 @@ pub(crate) fn invert(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<
         }
     };
     match args.get_err(0, "color")? {
-        Value::Color(c) => Ok(Value::Color(Box::new(c.invert(weight)))),
+        Value::Color(c) => Ok(Value::Color(Box::new(
-        Value::Dimension(Some(n), Unit::Percent, _) => {
+            c.invert(weight.unwrap_or(Number::one())),
-            Ok(Value::String(format!("invert({}%)", n), QuoteKind::None))
+        ))),
-        }
+        Value::Dimension(Some(n), u, _) => {
-        Value::Dimension(None, ..) => todo!(),
+            if weight.is_some() {
-        Value::Dimension(..) => Err((
+                Err((
                     "Only one argument may be passed to the plain-CSS invert() function.",
                     args.span(),
-        )
+                ))?;
-            .into()),
+            }
+            Ok(Value::String(
+                format!("invert({}{})", n, u),
+                QuoteKind::None,
+            ))
+        }
+        Value::Dimension(None, u, _) => {
+            Ok(Value::String(format!("invert(NaN{})", u), QuoteKind::None))
+        }
         v => Err((
             format!("$color: {} is not a color.", v.inspect(args.span())?),
             args.span(),

tests/color.rs

@@ -245,8 +245,46 @@ test!(
     "a {\n  color: invert(white);\n}\n",
     "a {\n  color: black;\n}\n"
 );
-test!(invert_number, "a {\n  color: invert(10%);\n}\n");
+test!(
-test!(invert_number_casing, "a {\n  color: iNveRt(10%);\n}\n");
+    plain_invert_no_unit,
+    "a {\n  color: invert(1);\n}\n",
+    "a {\n  color: invert(1);\n}\n"
+);
+test!(
+    plain_invert_unit_percent,
+    "a {\n  color: invert(10%);\n}\n",
+    "a {\n  color: invert(10%);\n}\n"
+);
+test!(
+    plain_invert_unit_deg,
+    "a {\n  color: invert(1deg);\n}\n",
+    "a {\n  color: invert(1deg);\n}\n"
+);
+test!(
+    plain_invert_negative,
+    "a {\n  color: invert(-1);\n}\n",
+    "a {\n  color: invert(-1);\n}\n"
+);
+test!(
+    plain_invert_float,
+    "a {\n  color: invert(1.5);\n}\n",
+    "a {\n  color: invert(1.5);\n}\n"
+);
+test!(
+    plain_invert_arithmetic,
+    "a {\n  color: invert(1 + 1);\n}\n",
+    "a {\n  color: invert(2);\n}\n"
+);
+test!(
+    plain_invert_nan,
+    "a {\n  color: invert((0 / 0));\n}\n",
+    "a {\n  color: invert(NaN);\n}\n"
+);
+error!(
+    plain_invert_two_args,
+    "a {\n  color: invert(1, 50%);\n}\n",
+    "Error: Only one argument may be passed to the plain-CSS invert() function."
+);
 test!(
     invert_weight_percent,
     "a {\n  color: invert(white, 20%);\n}\n",