feat(src/protocol.rs): add test

Add test for Brightness to u8 conversion.

Author: weberval

src/protocol.rs

@@ -509,10 +509,9 @@ impl DrawTarget for MessageBuffer<'_> {
 
 #[cfg(test)]
 mod test {
+    use super::{Brightness, Speed};
     use std::ops::Range;
 
-    use super::Speed;
-
     #[test]
     fn speed_to_u8_and_back() {
         const VALID_SPEED_VALUES: Range<u8> = 1..8;
@@ -524,4 +523,18 @@ mod test {
             }
         }
     }
+
+    #[test]
+    fn brightness_to_u8() {
+        const VALID_BRIGHTNESS_VALUES: [(Brightness, u8); 4] = [
+            (Brightness::Full, 0x00),
+            (Brightness::ThreeQuarters, 0x10),
+            (Brightness::Half, 0x20),
+            (Brightness::OneQuarter, 0x30),
+        ];
+
+        for i in VALID_BRIGHTNESS_VALUES {
+            assert_eq!(u8::from(Brightness::from(i.0)), i.1);
+        }
+    }
 }