Add initial test coverage for Drawable.prototype.getAABB

test/fixtures/MockSkin.js

@@ -0,0 +1,13 @@
+const Skin = require('../../src/Skin');
+
+class MockSkin extends Skin {
+    set size (dimensions) {
+        this.dimensions = dimensions;
+    }
+
+    get size () {
+        return this.dimensions || [0, 0];
+    }
+}
+
+module.exports = MockSkin;