✨ Add Set method to Metas and tests

models/metas.go

@@ -72,10 +72,28 @@ func (ms *Metas) AppendTo(k string, v any) {
 
 // Returns the value of the Meta with the given key, and a bool indicating if it was found
 func (ms Metas) Get(key string) (any, bool) {
-	for _, m := range ms {
+	_, m, ok := ms.findVal(key)
+	return m.Value, ok
+}
+
+// Set sets the key to the given value.
+// If key is already in the ms, Set updates the value of the found Meta.
+// If key is not in ms, then we append a new Meta and return the modified Metas.
+func (ms Metas) Set(key string, value any) Metas {
+	idx, m, found := ms.findVal(key)
+	if !found {
+		return ms.Append(key, value)
+	}
+	m.Value = value
+	ms[idx] = m
+	return ms
+}
+
+func (ms Metas) findVal(key string) (idx int, m Meta, found bool) {
+	for idx, m = range ms {
 		if m.Key == key {
-			return m.Value, true
+			return idx, m, true
 		}
 	}
-	return nil, false
+	return 0, Meta{}, false
 }