defaut constructor generate a blank grid

src/lib.rs

@@ -52,6 +52,25 @@ impl Universe{
         }
         count
     }
+
+    fn regenerate_cells(&mut self) {
+        let size = (self.width * self.height) as usize;
+        self.cells = FixedBitSet::with_capacity(size);
+        for i in 0..size {
+            self.cells.set(i, false);
+        }
+    }
+
+    pub fn get_cells(&self) -> &FixedBitSet {
+        &self.cells
+    }
+
+    pub fn set_cells(&mut self, cells: &[(u32, u32)]) {
+        for (row, col) in cells.iter().cloned() {
+            let i = self.get_index(row, col);
+            self.cells.set(i, true);
+        }
+    }
 }
 
 #[wasm_bindgen]
@@ -76,6 +95,16 @@ impl Universe {
         self.cells = next;
     }
 
+    pub fn set_width(&mut self, width: u32) {
+        self.width = width;
+        self.regenerate_cells();
+    }
+
+    pub fn set_height(&mut self, height: u32) {
+        self.height = height;
+        self.regenerate_cells();
+    }
+
     pub fn new() -> Universe {
         let width = 64;
         let height = 64;
@@ -84,7 +113,7 @@ impl Universe {
         let mut cells = FixedBitSet::with_capacity(size);
 
         for i in 0..size {
-            cells.set(i, i % 2 == 0 || i % 7 == 0);
+            cells.set(i, false);
         }
 
         Universe {
@@ -94,7 +123,7 @@ impl Universe {
         }
     }
 
-    pub fn new_random() -> Universe {
+    pub fn new_modulo() -> Universe {
         let width = 64;
         let height = 64;
         let size = (width * height) as usize;
@@ -102,7 +131,7 @@ impl Universe {
         let mut cells = FixedBitSet::with_capacity(size);
 
         for i in 0..size {
-            cells.set(i, js_sys::Math::random() < 0.5);
+            cells.set(i, i % 2 == 0 || i % 7 == 0);
         }
 
         Universe {
@@ -112,22 +141,15 @@ impl Universe {
         }
     }
 
-    pub fn new_space_ship() -> Universe {
-        let width : u32 = 64;
-        let height : u32 = 64;
+    pub fn new_random() -> Universe {
+        let width = 64;
+        let height = 64;
         let size = (width * height) as usize;
 
         let mut cells = FixedBitSet::with_capacity(size);
 
         for i in 0..size {
-            cells.set(i, false);
-        }
-
-        let x0 = 32;
-        let y0 = 32;
-        for (x, y) in [(0, 2), (1, 0), (1, 2), (2, 1), (2, 2)].iter().cloned() {
-            let i = ((y0 + y) * width + x0 + x) as usize;
-            cells.set(i, true);
+            cells.set(i, js_sys::Math::random() < 0.5);
         }
 
         Universe {
@@ -137,6 +159,20 @@ impl Universe {
         }
     }
 
+    pub fn new_space_ship() -> Universe {
+        let mut univese = Universe::new();
+        const X0: u32 = 32;
+        const Y0: u32 = 32;
+        let cells = &(
+            [(0, 2), (1, 0), (1, 2), (2, 1), (2, 2)]
+            .iter()
+            .map(|(x, y)| (X0+x, Y0+y))
+            .collect::<Vec<(u32, u32)>>()
+        );
+        univese.set_cells(cells);
+        univese
+    }
+
     pub fn render(&self) -> String {
         self.to_string()
     }

tests/web.rs

@@ -2,7 +2,9 @@
 
 #![cfg(target_arch = "wasm32")]
 
+extern crate wasm_game_of_life;
 extern crate wasm_bindgen_test;
+use wasm_game_of_life::Universe;
 use wasm_bindgen_test::*;
 
 wasm_bindgen_test_configure!(run_in_browser);
@@ -11,3 +13,29 @@ wasm_bindgen_test_configure!(run_in_browser);
 fn pass() {
     assert_eq!(1 + 1, 2);
 }
+
+#[cfg(test)]
+pub fn input_spaceship() -> Universe {
+    let mut universe = Universe::new();
+    universe.set_width(6);
+    universe.set_height(6);
+    universe.set_cells(&[(1,2), (2,3), (3,1), (3,2), (3,3)]);
+    universe
+}
+
+#[cfg(test)]
+pub fn expected_spaceship() -> Universe {
+    let mut universe = Universe::new();
+    universe.set_width(6);
+    universe.set_height(6);
+    universe.set_cells(&[(2,1), (2,3), (3,2), (3,3), (4,2)]);
+    universe
+}
+
+#[wasm_bindgen_test]
+pub fn test_tick() {
+    let mut input_universe = input_spaceship();
+    let expected_universe = expected_spaceship();
+    input_universe.tick();
+    assert_eq!(&input_universe.get_cells(), &expected_universe.get_cells());
+}

www

@@ -1 +1 @@
-Subproject commit f6fa2759a6dce5379554d7294f00487bb1565004
+Subproject commit 38933c4a49773b2c7acd9bdd9d398da278186ac3