Add initial proptests

src/common/transformation.rs

@@ -75,6 +75,7 @@ impl Transformable for Direction {
 #[cfg(test)]
 mod test {
     use crate::prelude::*;
+    use proptest::{prop_assert_eq, proptest};
 
     #[test]
     fn position() {
@@ -87,21 +88,16 @@ mod test {
         assert_eq!(p.transform(t), Position::new(-6, -10));
     }
 
-    #[test]
-    fn invert() {
-        let transformations = [
-            Transformation::new(Direction::Up, Position::new(-3, -5)),
-            Transformation::new(Direction::Right, Position::new(-3, -5)),
-            Transformation::new(Direction::Down, Position::new(-3, -5)),
-            Transformation::new(Direction::Left, Position::new(-3, -5)),
-        ];
+    proptest! {
+        #[test]
+        fn invert(dir: Direction, pos: Position) {
+            let o = Transformation::new(dir, pos);
 
-        for o in transformations {
             let i = o.invert();
             let c = o.chain(i);
 
-            assert_eq!(c.rot, Direction::Up, "o: {:?}, i: {:?}, c: {:?}", o, i, c);
-            assert_eq!(
+            prop_assert_eq!(c.rot, Direction::Up, "o: {:?}, i: {:?}, c: {:?}", o, i, c);
+            prop_assert_eq!(
                 c.pos,
                 Position::new(0, 0),
                 "o: {:?}, i: {:?}, c: {:?}",
@@ -109,6 +105,7 @@ mod test {
                 i,
                 c
             );
+
         }
     }
 }