✨ Add Set method to Metas and tests

models/meta_test.go

@@ -142,6 +142,66 @@ func TestMetasAppendTo(t *testing.T) {
 	assert.Equal(t, Meta{"foo", 42}, (*ms)[0])
 }
 
+func TestMetasSet(t *testing.T) {
+	tests := []struct {
+		name     string
+		initial  Metas
+		key      string
+		value    any
+		expected Metas
+	}{
+		{
+			name:     "Set new key",
+			initial:  Metas{},
+			key:      "foo",
+			value:    42,
+			expected: Metas{{"foo", 42}},
+		},
+		{
+			name:     "Update existing key",
+			initial:  Metas{{"foo", 1}},
+			key:      "foo",
+			value:    42,
+			expected: Metas{{"foo", 42}},
+		},
+		{
+			name:     "Update existing key with different type",
+			initial:  Metas{{"foo", "hello"}},
+			key:      "foo",
+			value:    42,
+			expected: Metas{{"foo", 42}},
+		},
+		{
+			name:     "Set multiple new keys",
+			initial:  Metas{},
+			key:      "bar",
+			value:    true,
+			expected: Metas{{"bar", true}},
+		},
+		{
+			name:     "Update one of multiple existing keys",
+			initial:  Metas{{"foo", 1}, {"bar", "hello"}},
+			key:      "foo",
+			value:    42,
+			expected: Metas{{"foo", 42}, {"bar", "hello"}},
+		},
+		{
+			name:     "Set new key when others exist",
+			initial:  Metas{{"foo", 1}, {"bar", "hello"}},
+			key:      "baz",
+			value:    false,
+			expected: Metas{{"foo", 1}, {"bar", "hello"}, {"baz", false}},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := tt.initial.Set(tt.key, tt.value)
+			assert.ElementsMatch(t, tt.expected, result)
+		})
+	}
+}
+
 func TestMetasGet(t *testing.T) {
 	ms := Metas{{"foo", 42}, {"bar", "hello"}}
 

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
 }