Improve error handling for duration parsing

runtime/duration.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"strconv"
 	"time"
+
+	"github.com/pkg/errors"
 )
 
 // Duration is a TOML datatype
@@ -32,7 +34,7 @@ func (d *Duration) UnmarshalTOML(dataInterface interface{}) error {
 	unit := data[len(data)-1]
 	value, err := strconv.Atoi(string(data[:len(data)-1]))
 	if err != nil {
-		return fmt.Errorf("unable to parse duration %s: %s", data, err)
+		return errors.Wrapf(err, "unable to parse duration \"%s\"", data)
 	}
 
 	switch unit {
@@ -49,7 +51,7 @@ func (d *Duration) UnmarshalTOML(dataInterface interface{}) error {
 	case 'y':
 		d.Duration = time.Duration(value) * time.Hour * 24 * 365
 	default:
-		return fmt.Errorf("invalid duration unit: %s", string(unit))
+		return fmt.Errorf("invalid duration unit \"%s\"", string(unit))
 	}
 
 	return nil

runtime/duration_test.go

@@ -16,7 +16,7 @@ func TestDuration(t *testing.T) {
 		duration time.Duration
 	}{
 		{"", "invalid duration: \"\"", 0},
-		{"1x", "invalid duration unit: x", 0},
+		{"1x", "invalid duration unit \"x\"", 0},
 		{"1s", "", time.Second},
 		{"73s", "", time.Second * 73},
 		{"1m", "", time.Minute},
@@ -52,6 +52,5 @@ func TestDuration(t *testing.T) {
 
 	err = d.UnmarshalTOML("am")
 	assert.Error(err)
-	assert.Contains(err.Error(), "unable to parse duration")
-
+	assert.EqualError(err, "unable to parse duration \"am\": strconv.Atoi: parsing \"a\": invalid syntax")
 }