improve handling of $base to math.log

src/builtin/modules/math.rs

@@ -225,7 +225,7 @@ fn log(mut args: CallArgs, _: &mut Parser) -> SassResult<Value> {
             if base.is_zero() {
                 Some(Number::zero())
             } else {
-                (|| Some(number.ln()? / base.ln()?))()
+                number.log(base)
             }
         } else if number.is_negative() {
             None

src/value/number/mod.rs

@@ -29,8 +29,12 @@ impl PartialEq for Number {
     fn eq(&self, other: &Self) -> bool {
         match (self, other) {
             (Number::Small(val1), Number::Small(val2)) => val1 == val2,
-            (Number::Big(val1), val2 @ Number::Small(..)) => **val1 == val2.clone().into_big_rational(),
+            (Number::Big(val1), val2 @ Number::Small(..)) => {
-            (val1 @ Number::Small(..), Number::Big(val2)) => val1.clone().into_big_rational() == **val2,
+                **val1 == val2.clone().into_big_rational()
+            }
+            (val1 @ Number::Small(..), Number::Big(val2)) => {
+                val1.clone().into_big_rational() == **val2
+            }
             (Number::Big(val1), Number::Big(val2)) => val1 == val2,
         }
     }
@@ -135,7 +139,7 @@ impl Number {
     }
 
     #[allow(clippy::cast_precision_loss)]
-    fn as_float(self) -> Option<f64> {
+    pub fn as_float(self) -> Option<f64> {
         Some(match self {
             Number::Small(n) => ((*n.numer() as f64) / (*n.denom() as f64)),
             Number::Big(n) => ((n.numer().to_f64()?) / (n.denom().to_f64()?)),
@@ -154,6 +158,12 @@ impl Number {
         )?)))
     }
 
+    pub fn log(self, base: Number) -> Option<Self> {
+        Some(Number::Big(Box::new(BigRational::from_float(
+            self.as_float()?.log(base.as_float()?),
+        )?)))
+    }
+
     pub fn pow(self, exponent: Self) -> Option<Self> {
         Some(Number::Big(Box::new(BigRational::from_float(
             self.as_float()?.powf(exponent.as_float()?),

tests/math-module.rs

@@ -598,3 +598,12 @@ test!(
     "@use 'sass:math';\na {\n  color: math.div(\"1\",\"2\");\n}\n",
     "a {\n  color: \"1\"/\"2\";\n}\n"
 );
+test!(
+    log_returns_whole_number_for_simple_base,
+    "@use 'sass:math';
+    a {
+      color: math.log(8, 2);
+      color: math.floor(math.log(8, 2));
+    }",
+    "a {\n  color: 3;\n  color: 3;\n}\n"
+);