Add Tests to Simulation

test/simulation_test.dart

@@ -0,0 +1,37 @@
+import 'dart:math';
+import 'package:mockito/mockito.dart';
+import 'package:rules_of_living/src/Grid.dart';
+import 'package:test/test.dart';
+
+import 'package:rules_of_living/src/Simulation.dart';
+
+void main() {
+  Simulation sut;
+  setUp(() {
+    sut = Simulation(10, 10);
+  });
+  group("gridSize", () {
+    test(
+        "returns the width and height of the underlying grid",
+        () => expect(
+            sut.gridSize, equals(Point<int>(sut.map.width, sut.map.height))));
+    test("sets the underlying grid width and height", () {
+      sut.gridSize = Point(2, 3);
+      expect(sut.gridSize, equals(Point(2, 3)));
+    });
+    test("creates a new underlying grid on resizing", () {
+      var oldMap = sut.map;
+      sut.gridSize = Point(10, 10);
+      expect(sut.map, isNot(oldMap));
+    });
+  });
+  group("reset", () {
+    test("returns a map filled with 'false' ", () {
+      expect(sut.reset(), allOf(TypeMatcher<Grid>(), isNot(contains(true))));
+    });
+    test("sets the simulation to need re-rendering", () {
+      sut.reset();
+      expect(sut.dirty, true);
+    }, skip: "can not find a way to set dirty to true first yet");
+  });
+}