fix: Logic error in MemoryCache.setValue()

packages/flame/lib/src/cache/memory_cache.dart

@@ -1,17 +1,20 @@
 import 'dart:collection';
 
 /// Simple class to cache values with size based eviction.
-///
 class MemoryCache<K, V> {
  final LinkedHashMap<K, V> _cache = LinkedHashMap();
  final int cacheSize;
 
  MemoryCache({this.cacheSize = 10});
 
+ /// Adds the [value] to the cache under [key].
+ ///
+ /// If that [key] is already used, updates the value.
  void setValue(K key, V value) {
- if (!_cache.containsKey(key)) {
-  _cache[key] = value;
+ final preexisting = _cache.containsKey(key);
+ _cache[key] = value;
 
+ if (!preexisting) {
  while (_cache.length > cacheSize) {
  final k = _cache.keys.first;
  _cache.remove(k);
@@ -29,11 +32,15 @@ class MemoryCache<K, V> {
  _cache.clear();
  }
 
+ /// Gets the value under [key].
  V? getValue(K key) => _cache[key];
 
+ /// Checks whether the cache has any value under [key].
  bool containsKey(K key) => _cache.containsKey(key);
 
+ /// Returns the number of values saved in this memory cache.
  int get size => _cache.length;
 
+ /// Iterates over all existing keys with values.
  Iterable<K> get keys => _cache.keys;
 }

packages/flame/test/cache/memory_cache_test.dart

@@ -18,6 +18,14 @@ void main() {
  expect(cache.keys.length, 1);
  });
 
+ test('updates key', () {
+ final cache = MemoryCache<int, String>();
+ cache.setValue(0, 'bla');
+ expect(cache.getValue(0), 'bla');
+ cache.setValue(0, 'ble');
+ expect(cache.getValue(0), 'ble');
+ });
+
  test('cache size', () {
  final cache = MemoryCache<int, String>(cacheSize: 1);
  cache.setValue(0, 'bla');