implement builtin function math.pow

src/builtin/modules/math.rs

@@ -174,7 +174,52 @@ fn log(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value> {
 
 fn pow(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value> {
     args.max_args(2)?;
-    todo!()
+
+    let base = match args.get_err(0, "base")? {
+        Value::Dimension(Some(n), Unit::None, ..) => n,
+        v @ Value::Dimension(Some(..), ..) => {
+            return Err((
+                format!(
+                    "$base: Expected {} to have no units.",
+                    v.inspect(args.span())?
+                ),
+                args.span(),
+            )
+                .into())
+        }
+        Value::Dimension(None, ..) => return Ok(Value::Dimension(None, Unit::None, true)),
+        v => {
+            return Err((
+                format!("$base: {} is not a number.", v.inspect(args.span())?),
+                args.span(),
+            )
+                .into())
+        }
+    };
+
+    let exponent = match args.get_err(1, "exponent")? {
+        Value::Dimension(Some(n), Unit::None, ..) => n,
+        v @ Value::Dimension(Some(..), ..) => {
+            return Err((
+                format!(
+                    "$exponent: Expected {} to have no units.",
+                    v.inspect(args.span())?
+                ),
+                args.span(),
+            )
+                .into())
+        }
+        Value::Dimension(None, ..) => return Ok(Value::Dimension(None, Unit::None, true)),
+        v => {
+            return Err((
+                format!("$exponent: {} is not a number.", v.inspect(args.span())?),
+                args.span(),
+            )
+                .into())
+        }
+    };
+
+    Ok(Value::Dimension(base.pow(exponent), Unit::None, true))
 }
 
 fn sqrt(mut args: CallArgs, parser: &mut Parser<'_>) -> SassResult<Value> {
@@ -375,6 +420,7 @@ pub(crate) fn declare(f: &mut Module) {
     f.insert_builtin("asin", asin);
     f.insert_builtin("atan", atan);
     f.insert_builtin("log", log);
+    f.insert_builtin("pow", pow);
     #[cfg(feature = "random")]
     f.insert_builtin("random", random);
 

src/value/number/mod.rs

@@ -128,6 +128,12 @@ impl Number {
             self.as_float()?.ln(),
         )?)))
     }
+
+    pub fn pow(self, exponent: Self) -> Option<Self> {
+        Some(Number::Big(Box::new(BigRational::from_float(
+            self.as_float()?.powf(exponent.as_float()?),
+        )?)))
+    }
 }
 
 macro_rules! trig_fn(

tests/math-module.rs

@@ -390,3 +390,59 @@ test!(
     "@use 'sass:math';\na {\n  color: math.log(2, .5);\n}\n",
     "a {\n  color: -1;\n}\n"
 );
+
+test!(
+    pow_exponent_and_base_one,
+    "@use 'sass:math';\na {\n  color: math.pow(1, 1);\n}\n",
+    "a {\n  color: 1;\n}\n"
+);
+test!(
+    pow_exponent_and_base_ten,
+    "@use 'sass:math';\na {\n  color: math.pow(10, 10);\n}\n",
+    "a {\n  color: 10000000000;\n}\n"
+);
+test!(
+    pow_base_negative_exponent_positive,
+    "@use 'sass:math';\na {\n  color: math.pow(-2, 3);\n}\n",
+    "a {\n  color: -8;\n}\n"
+);
+test!(
+    pow_base_positive_exponent_negative,
+    "@use 'sass:math';\na {\n  color: math.pow(2, -3);\n}\n",
+    "a {\n  color: 0.125;\n}\n"
+);
+test!(
+    pow_base_negative_exponent_negative,
+    "@use 'sass:math';\na {\n  color: math.pow(-2, -3);\n}\n",
+    "a {\n  color: -0.125;\n}\n"
+);
+test!(
+    pow_base_decimal,
+    "@use 'sass:math';\na {\n  color: math.pow(2.4, 3);\n}\n",
+    "a {\n  color: 13.824;\n}\n"
+);
+test!(
+    pow_exponent_decimal,
+    "@use 'sass:math';\na {\n  color: math.pow(2, 3.5);\n}\n",
+    "a {\n  color: 11.313708499;\n}\n"
+);
+test!(
+    pow_base_nan,
+    "@use 'sass:math';\na {\n  color: math.pow((0 / 0), 3);\n}\n",
+    "a {\n  color: NaN;\n}\n"
+);
+test!(
+    pow_exponent_nan,
+    "@use 'sass:math';\na {\n  color: math.pow(2, (0 / 0));\n}\n",
+    "a {\n  color: NaN;\n}\n"
+);
+test!(
+    pow_base_and_exponent_nan,
+    "@use 'sass:math';\na {\n  color: math.pow((0 / 0), (0 / 0));\n}\n",
+    "a {\n  color: NaN;\n}\n"
+);
+test!(
+    pow_exponent_zero,
+    "@use 'sass:math';\na {\n  color: math.pow(2, 0);\n}\n",
+    "a {\n  color: 1;\n}\n"
+);