add unit tests

crates/servicepoint/src/command.rs

@@ -495,7 +495,8 @@ mod tests {
         command_code::CommandCode,
         origin::Pixels,
         packet::{Header, Packet},
-        Brightness, Command, CompressionCode, Origin, PixelGrid, PrimitiveGrid,
+        Brightness, BrightnessGrid, Command, CompressionCode, Origin,
+        PixelGrid, PrimitiveGrid,
     };
 
     fn round_trip(original: Command) {
@@ -902,4 +903,27 @@ mod tests {
             Origin::new(1, 0) + Origin::new(3, 2)
         );
     }
+    #[test]
+    fn packet_into_char_brightness_invalid() {
+        let grid = BrightnessGrid::new(2, 2);
+        let command = Command::CharBrightness(Origin::ZERO, grid);
+        let mut packet: Packet = command.into();
+        let slot = packet.payload.get_mut(1).unwrap();
+        *slot = 23;
+        assert_eq!(
+            Command::try_from(packet),
+            Err(TryFromPacketError::InvalidBrightness(23))
+        );
+    }
+
+    #[test]
+    fn packet_into_brightness_invalid() {
+        let mut packet: Packet = Command::Brightness(Brightness::MAX).into();
+        let slot = packet.payload.get_mut(0).unwrap();
+        *slot = 42;
+        assert_eq!(
+            Command::try_from(packet),
+            Err(TryFromPacketError::InvalidBrightness(42))
+        );
+    }
 }

crates/servicepoint/src/cp437.rs

@@ -14,7 +14,7 @@ pub type Cp437Grid = PrimitiveGrid<u8>;
 pub type CharGrid = PrimitiveGrid<char>;
 
 /// Errors that can occur when loading CP-437.
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum Cp437LoadError {
     /// Invalid character in input prevented loading
     InvalidChar {
@@ -232,6 +232,17 @@ mod tests {
         // line break will be added
         assert_eq!(actual, expected);
     }
+
+    #[test]
+    fn load_ascii_invalid() {
+        assert_eq!(
+            Err(Cp437LoadError::InvalidChar {
+                char: '🥶',
+                index: 2
+            }),
+            Cp437Grid::load_ascii("?#🥶42", 3, false)
+        );
+    }
 }
 
 #[cfg(test)]

crates/servicepoint/src/grid.rs

@@ -76,15 +76,9 @@ pub trait Grid<T> {
     ///
     /// When the specified position is out of bounds for this grid.
     fn assert_in_bounds(&self, x: usize, y: usize) {
-        assert!(
-            x < self.width(),
-            "cannot access index [{x}, {y}] because x is outside of bounds 0..{}",
-            self.width() - 1
-        );
-        assert!(
-            y < self.height(),
-            "cannot access index [{x}, {y}] because y is outside of bounds 0..{}",
-            self.height() - 1
-        );
+        let width = self.width();
+        assert!(x < width, "cannot access index [{x}, {y}] because x is outside of bounds [0..{width})");
+        let height = self.height();
+        assert!(y < height, "cannot access index [{x}, {y}] because x is outside of bounds [0..{height})");
     }
 }