Explicitly remove nonexistence sentinel on set

Author: nickstenning

cache/cache.go

@@ -217,6 +217,12 @@ func (c *Cache[T]) set(ctx context.Context, key string, value T) error {
 		return err
 	}
 
+	// Remove any explicit nonexistence sentinel
+	err = c.client.Del(ctx, keys.negative).Err()
+	if err != nil {
+		return err
+	}
+
 	// Update cached value
 	err = c.client.Set(ctx, keys.data, string(data), c.opts.Stale).Err()
 	if err != nil {

cache/cache_test.go

@@ -72,6 +72,7 @@ func (m mockWrapper) ExpectCacheFill(key string, value any) {
 	if err != nil {
 		panic(err)
 	}
+	m.ExpectDel("cache:negative:" + m.name + ":" + key).SetVal(0)
 	m.ExpectSet("cache:data:"+m.name+":"+key, string(data), m.stale).SetVal("OK")
 	m.ExpectSet("cache:fresh:"+m.name+":"+key, 1, m.fresh).SetVal("OK")
 }