decoder: handle casting local date into time.Time

Refs #494

README.md

@@ -23,6 +23,7 @@ Development branch. Use at your own risk.
 - [x] Original go-toml testgen tests pass.
 - [x] Track file position (line, column) for errors.
 - [ ] Strict mode.
+- [ ] Document Unmarshal / Decode
 
 ### Marshal
 

unmarshaler.go

@@ -30,6 +30,9 @@ func NewDecoder(r io.Reader) *Decoder {
 }
 
 // Decode the whole content of r into v.
+//
+// When a TOML local date is decoded into a time.Time, its value is represented
+// in time.Local timezone.
 func (d *Decoder) Decode(v interface{}) error {
 	b, err := ioutil.ReadAll(d.r)
 	if err != nil {
@@ -224,6 +227,13 @@ func tryTextUnmarshaler(x target, node ast.Node) (bool, error) {
 	if v.Kind() != reflect.Struct {
 		return false, nil
 	}
+
+	// Special case for time, becase we allow to unmarshal to it from
+	// different kind of AST nodes.
+	if v.Type() == timeType {
+		return false, nil
+	}
+
 	if v.Type().Implements(textUnmarshalerType) {
 		return true, v.Interface().(encoding.TextUnmarshaler).UnmarshalText(node.Data)
 	}
@@ -313,7 +323,14 @@ func setDateTime(x target, v time.Time) error {
 	return x.set(reflect.ValueOf(v))
 }
 
+var timeType = reflect.TypeOf(time.Time{})
+
 func setDate(x target, v LocalDate) error {
+	if x.get().Type() == timeType {
+		cast := v.In(time.Local)
+		return setDateTime(x, cast)
+	}
+
 	return x.set(reflect.ValueOf(v))
 }
 

unmarshaler_test.go

@@ -4,6 +4,7 @@ import (
 	"math"
 	"strconv"
 	"testing"
+	"time"
 
 	"github.com/pelletier/go-toml/v2"
 	"github.com/stretchr/testify/assert"
@@ -780,6 +781,20 @@ val1 = "test1"
 	require.Equal(t, "test2", cfg.Val2)
 }
 
+func TestIssue494(t *testing.T) {
+	data := `
+foo = 2021-04-08
+bar = 2021-04-08
+`
+	type s struct {
+		Foo time.Time `toml:"foo"`
+		Bar time.Time `toml:"bar"`
+	}
+	ss := new(s)
+	err := toml.Unmarshal([]byte(data), ss)
+	require.NoError(t, err)
+}
+
 func TestUnmarshalDecodeErrors(t *testing.T) {
 	examples := []struct {
 		desc string