Fix optional

CHANGELOG.md

@@ -7,6 +7,12 @@ The format is based on
 project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html): TBD, use modules or another vendor system.
 
+## v1.6.3
+
+### Fixed
+
+- Fix `optional` fields resolving.
+
 ## v1.6.2
 
 ### Fixed

container_test.go

@@ -976,6 +976,25 @@ func TestContainer_Inject(t *testing.T) {
 		require.Nil(t, extracted.server)
 	})
 
+	t.Run("resolve group in params", func(t *testing.T) {
+		c, err := di.New()
+		require.NoError(t, err)
+
+		type Fn func()
+		type Params struct {
+			di.Inject
+			Handlers []Fn `optional:"true"`
+		}
+		require.NoError(t, c.Provide(func() Fn { return func() {} }))
+		require.NoError(t, c.Provide(func() Fn { return func() {} }))
+		require.NoError(t, c.Provide(func(params Params) bool {
+			return len(params.Handlers) == 2
+		}))
+		var extracted bool
+		require.NoError(t, c.Resolve(&extracted))
+		require.True(t, extracted)
+	})
+
 	t.Run("optional group may be nil", func(t *testing.T) {
 		c, err := di.New()
 		require.NoError(t, err)

inject.go

@@ -45,6 +45,7 @@ type field struct {
 func parseField(f reflect.StructField) (field, bool) {
 	tags := Tags{}
 	t := string(f.Tag)
+	optional := false
 	// this code copied from reflect.StructField.Lookup() method.
 	for t != "" {
 		// Skip leading space.
@@ -91,12 +92,18 @@ func parseField(f reflect.StructField) (field, bool) {
 		if name == "skip" && value == "true" {
 			return field{}, false
 		}
+		if name == "optional" {
+			if value == "true" {
+				optional = true
+			}
+			continue
+		}
 		tags[name] = value
 	}
 	return field{
 		rt:       f.Type,
 		tags:     tags,
-		optional: tags["optional"] == "true",
+		optional: optional,
 	}, true
 }