Use the len from plane and add testing for evolve method

1 files changed, 51 insertions, 3 deletions

diff --git a/CLI/rust/src/game_of_life/simulation/universe.rs b/CLI/rust/src/game_of_life/simulation/universe.rs
index e91e1bd..4dfde92 100644
--- a/CLI/rust/src/game_of_life/simulation/universe.rs
+++ b/CLI/rust/src/game_of_life/simulation/universe.rs
@@ -98,9 +98,11 @@ impl Universe {
         ]
     }
 
-    pub(crate) fn evolve(&mut self) -> &Self {
-        for row in 0..self.opts.height {
-            for col in 0..self.opts.width {
+    /// Update the current state of the universe (according to the game of life laws) and
+    /// set the current state to the next future generation
+    pub(crate) fn evolve(mut self) -> Self {
+        for row in 0..self.current.len() {
+            for col in 0..self.current.0.len() as isize {
                 let living_neighbors = self
                     .neighbors(row, col)
                     .iter()
@@ -248,3 +250,49 @@ mod neighbors {
         assert_eq!(u.neighbors(0, 0), vec![true; 8]);
     }
 }
+
+#[cfg(test)]
+mod evolve {
+    use super::*;
+
+    fn opts() -> Opts {
+        Opts {
+            seed: 1337,
+            input: None,
+            width: 13,
+            height: 13,
+            live_cell: 'L',
+            dead_cell: 'D',
+            delay: 13,
+        }
+    }
+
+    #[test]
+    fn blinker() {
+        let universe = Universe {
+            opts: opts(),
+            future: Plane(vec![Plane(vec![false; 5]); 3]),
+            current: Plane(vec![
+                Plane(vec![false, false, false, false, false]),
+                Plane(vec![false, true, true, true, false]),
+                Plane(vec![false, false, false, false, false]),
+            ]),
+        };
+        assert_eq!(
+            universe.evolve(),
+            Universe {
+                opts: opts(),
+                future: Plane(vec![
+                    Plane(vec![false, false, true, false, false]),
+                    Plane(vec![false, false, true, false, false]),
+                    Plane(vec![false, false, true, false, false]),
+                ]),
+                current: Plane(vec![
+                    Plane(vec![false, false, true, false, false]),
+                    Plane(vec![false, false, true, false, false]),
+                    Plane(vec![false, false, true, false, false]),
+                ]),
+            }
+        )
+    }
+}