From 116bb43bd549fd553fa9009f0a014159a1da055d Mon Sep 17 00:00:00 2001
From: ConnorSkees <39542938+ConnorSkees@users.noreply.github.com>
Date: Sun, 9 Feb 2020 16:10:32 -0500
Subject: [PATCH] Implement builtin function `round()`

---
 src/builtin/math.rs |  9 +++++++--
 tests/math.rs       | 10 ++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/builtin/math.rs b/src/builtin/math.rs
index 25a1f7b..5ea9bb6 100644
--- a/src/builtin/math.rs
+++ b/src/builtin/math.rs
@@ -6,11 +6,16 @@ use crate::value::{Number, Value};
 
 pub(crate) fn register(f: &mut BTreeMap<String, Builtin>) {
     decl!(f "percentage", |args, _| {
-        let arg = dbg!(arg!(args, 0, "number").eval());
-        let num = match arg {
+        let num = match arg!(args, 0, "number").eval() {
             Value::Dimension(n, Unit::None) => n * Number::from(100),
             _ => todo!("expected unitless number in builtin function `percentage()`")
         };
         Some(Value::Dimension(num, Unit::Percent))
     });
+    decl!(f "round", |args, _| {
+        match arg!(args, 0, "number").eval() {
+            Value::Dimension(n, u) => Some(Value::Dimension(n.round(), u)),
+            _ => todo!("expected number in builtin function `round()`")
+        }
+    });
 }
\ No newline at end of file
diff --git a/tests/math.rs b/tests/math.rs
index 68b1e32..65fe25a 100644
--- a/tests/math.rs
+++ b/tests/math.rs
@@ -18,3 +18,13 @@ test!(
     "a {\n  color: percentage(2);\n}\n",
     "a {\n  color: 200%;\n}\n"
 );
+test!(
+    rounds_down,
+    "a {\n  color: round(10.4px);\n}\n",
+    "a {\n  color: 10px;\n}\n"
+);
+test!(
+    rounds_up,
+    "a {\n  color: round(10.6px);\n}\n",
+    "a {\n  color: 11px;\n}\n"
+);