tests: revamp tests, remove more useless tests

tests/directional.rs

@@ -19,7 +19,7 @@ fn mock_animated_texture(id: u32) -> AnimatedTexture {
 }
 
 #[test]
-fn test_partial_directions() {
+fn test_directional_texture_partial_directions() {
     let mut textures = HashMap::new();
     textures.insert(Direction::Up, mock_animated_texture(1));
 
@@ -33,18 +33,23 @@ fn test_partial_directions() {
 }
 
 #[test]
-fn test_all_directions() {
+fn test_directional_texture_all_directions() {
     let mut textures = HashMap::new();
-    textures.insert(Direction::Up, mock_animated_texture(1));
-    textures.insert(Direction::Down, mock_animated_texture(2));
-    textures.insert(Direction::Left, mock_animated_texture(3));
-    textures.insert(Direction::Right, mock_animated_texture(4));
+    let directions = [
+        (Direction::Up, 1),
+        (Direction::Down, 2),
+        (Direction::Left, 3),
+        (Direction::Right, 4),
+    ];
+
+    for (direction, id) in directions {
+        textures.insert(direction, mock_animated_texture(id));
+    }
 
     let texture = DirectionalAnimatedTexture::new(textures, HashMap::new());
 
     assert_eq!(texture.texture_count(), 4);
-    assert!(texture.has_direction(Direction::Up));
-    assert!(texture.has_direction(Direction::Down));
-    assert!(texture.has_direction(Direction::Left));
-    assert!(texture.has_direction(Direction::Right));
+    for direction in &[Direction::Up, Direction::Down, Direction::Left, Direction::Right] {
+        assert!(texture.has_direction(*direction));
+    }
 }