From 48abf1061bdf6023cd1df56dcf66dc4b78978892 Mon Sep 17 00:00:00 2001
From: Thomas Pelletier <pelletier.thomas@gmail.com>
Date: Sat, 12 Sep 2020 18:39:07 -0400
Subject: [PATCH 1/2] toml.Unmarshaler supports leaf nodes

---
 marshal.go      | 12 +++++++++++-
 marshal_test.go | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/marshal.go b/marshal.go
index 032e0ffc..f8eba8a6 100644
--- a/marshal.go
+++ b/marshal.go
@@ -1004,8 +1004,18 @@ func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}, mval1 *ref
 		return reflect.ValueOf(nil), fmt.Errorf("Can't convert %v(%T) to a slice", tval, tval)
 	default:
 		d.visitor.visit()
+		mvalPtr := reflect.New(mtype)
+
+		// Check if pointer to value implements the Unmarshaler interface.
+		if isCustomUnmarshaler(mvalPtr.Type()) {
+			if err := callCustomUnmarshaler(mvalPtr, tval); err != nil {
+				return reflect.ValueOf(nil), fmt.Errorf("unmarshal toml: %v", err)
+			}
+			return mvalPtr.Elem(), nil
+		}
+
 		// Check if pointer to value implements the encoding.TextUnmarshaler.
-		if mvalPtr := reflect.New(mtype); isTextUnmarshaler(mvalPtr.Type()) && !isTimeType(mtype) {
+		if isTextUnmarshaler(mvalPtr.Type()) && !isTimeType(mtype) {
 			if err := d.unmarshalText(tval, mvalPtr); err != nil {
 				return reflect.ValueOf(nil), fmt.Errorf("unmarshal text: %v", err)
 			}
diff --git a/marshal_test.go b/marshal_test.go
index d72926bf..b77cc79b 100644
--- a/marshal_test.go
+++ b/marshal_test.go
@@ -3976,3 +3976,37 @@ func TestGithubIssue431(t *testing.T) {
 		t.Errorf("UnmarshalTOML should not have been called")
 	}
 }
+
+type DurationString struct {
+	time.Duration
+}
+
+func (d *DurationString) UnmarshalTOML(v interface{}) error {
+	d.Duration = 10 * time.Second
+	return nil
+}
+
+type Config437 struct {
+	HTTP struct {
+		PingTimeout DurationString `toml:"PingTimeout"`
+	} `toml:"HTTP"`
+}
+
+func TestGithubIssue437(t *testing.T) {
+	src := `
+[HTTP]
+PingTimeout = "32m"
+`
+	cfg := &Config437{}
+	cfg.HTTP.PingTimeout = DurationString{time.Second}
+
+	r := strings.NewReader(src)
+	err := NewDecoder(r).Decode(cfg)
+	if err != nil {
+		t.Fatalf("unexpected errors %s", err)
+	}
+	expected := DurationString{10 * time.Second}
+	if cfg.HTTP.PingTimeout != expected {
+		t.Fatalf("expected '%s', got '%s'", expected, cfg.HTTP.PingTimeout)
+	}
+}

From dcc96feae2447cfff215076d04f3f23a6f16b783 Mon Sep 17 00:00:00 2001
From: Thomas Pelletier <pelletier.thomas@gmail.com>
Date: Sat, 12 Sep 2020 18:54:15 -0400
Subject: [PATCH 2/2] Add test for error

---
 marshal_test.go | 37 ++++++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

diff --git a/marshal_test.go b/marshal_test.go
index b77cc79b..c61955d5 100644
--- a/marshal_test.go
+++ b/marshal_test.go
@@ -3,6 +3,7 @@ package toml
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -3977,18 +3978,26 @@ func TestGithubIssue431(t *testing.T) {
 	}
 }
 
-type DurationString struct {
+type durationString struct {
 	time.Duration
 }
 
-func (d *DurationString) UnmarshalTOML(v interface{}) error {
+func (d *durationString) UnmarshalTOML(v interface{}) error {
 	d.Duration = 10 * time.Second
 	return nil
 }
 
-type Config437 struct {
+type config437Error struct {
+}
+
+func (e *config437Error) UnmarshalTOML(v interface{}) error {
+	return errors.New("expected")
+}
+
+type config437 struct {
 	HTTP struct {
-		PingTimeout DurationString `toml:"PingTimeout"`
+		PingTimeout durationString `toml:"PingTimeout"`
+		ErrorField  config437Error
 	} `toml:"HTTP"`
 }
 
@@ -3997,16 +4006,30 @@ func TestGithubIssue437(t *testing.T) {
 [HTTP]
 PingTimeout = "32m"
 `
-	cfg := &Config437{}
-	cfg.HTTP.PingTimeout = DurationString{time.Second}
+	cfg := &config437{}
+	cfg.HTTP.PingTimeout = durationString{time.Second}
 
 	r := strings.NewReader(src)
 	err := NewDecoder(r).Decode(cfg)
 	if err != nil {
 		t.Fatalf("unexpected errors %s", err)
 	}
-	expected := DurationString{10 * time.Second}
+	expected := durationString{10 * time.Second}
 	if cfg.HTTP.PingTimeout != expected {
 		t.Fatalf("expected '%s', got '%s'", expected, cfg.HTTP.PingTimeout)
 	}
 }
+
+func TestLeafUnmarshalerError(t *testing.T) {
+	src := `
+[HTTP]
+ErrorField = "foo"
+`
+	cfg := &config437{}
+
+	r := strings.NewReader(src)
+	err := NewDecoder(r).Decode(cfg)
+	if err == nil {
+		t.Fatalf("error was expected")
+	}
+}