Merge pull request #25 from albenik/struct-unmarshaler

Unmarshaler interface can be used with struct now

.travis.yml

@@ -1,12 +1,7 @@
 language: go
 
 go:
-    - 1.5
-    - 1.6
-    - 1.7
-    - 1.8
-    - 1.9
-    - "1.10"
-    - "1.11"
-    - "1.12"
-    - tip
+  - "1.12"
+  - "1.13"
+  - "1.14"
+  - tip

envconfig.go

@@ -148,9 +148,11 @@ func readStruct(value reflect.Value, ctx *context) (nonNil bool, err error) {
 
 	for i := 0; i < value.NumField(); i++ {
 		field := value.Field(i)
-		name := value.Type().Field(i).Name
+		fieldType := field.Type()
+		fieldInfo := value.Type().Field(i)
+		name := fieldInfo.Name
 
-		tag := parseTag(value.Type().Field(i).Tag.Get("envconfig"))
+		tag := parseTag(fieldInfo.Tag.Get("envconfig"))
 		if tag.skip || !field.CanSet() {
 			if !field.CanSet() && !ctx.allowUnexported {
 				return false, ErrUnexportedField
@@ -161,16 +163,16 @@ func readStruct(value reflect.Value, ctx *context) (nonNil bool, err error) {
 		parents = ctx.parents
 
 	doRead:
-		switch field.Kind() {
-		case reflect.Ptr:
+		switch {
+		case field.Kind() == reflect.Ptr && !isUnmarshaler(fieldType):
 			// it's a pointer, create a new value and restart the switch
 			if field.IsNil() {
 				field.Set(reflect.New(field.Type().Elem()))
 				parents = append(parents, field) // track parent pointers to deallocate if no children are filled in
 			}
 			field = field.Elem()
 			goto doRead
-		case reflect.Struct:
+		case field.Kind() == reflect.Struct && !isUnmarshaler(fieldType):
 			var nonNilIn bool
 			nonNilIn, err = readStruct(field, &context{
 				name:            combineName(ctx.name, name),
@@ -267,8 +269,8 @@ func setSliceField(value reflect.Value, str string, ctx *context) error {
 }
 
 var (
-	durationType    = reflect.TypeOf(new(time.Duration)).Elem()
-	unmarshalerType = reflect.TypeOf(new(Unmarshaler)).Elem()
+	durationType    = reflect.TypeOf((*time.Duration)(nil)).Elem()
+	unmarshalerType = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
 )
 
 func isDurationField(t reflect.Type) bool {
@@ -323,7 +325,15 @@ func parseValue(v reflect.Value, str string, ctx *context) (err error) {
 }
 
 func parseWithUnmarshaler(v reflect.Value, str string) error {
-	var u = v.Addr().Interface().(Unmarshaler)
+	var u Unmarshaler
+	if v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			v.Set(reflect.New(v.Type().Elem()))
+		}
+		u = v.Interface().(Unmarshaler)
+	} else {
+		u = v.Addr().Interface().(Unmarshaler)
+	}
 	return u.Unmarshal(str)
 }
 

go.mod

@@ -1 +1,12 @@
 module github.com/vrischmann/envconfig
+
+go 1.12
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
+	github.com/stretchr/testify v1.6.1
+	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 // indirect
+)

go.sum

@@ -0,0 +1,25 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
+github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
+gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 h1:tQIYjPdBoyREyB9XMu+nnTclpTYkz2zFM+lzLJFO4gQ=
+gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

structunmarshaler_test.go

@@ -0,0 +1,48 @@
+package envconfig_test
+
+import (
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/vrischmann/envconfig"
+)
+
+type dateUnmarshaller time.Time
+
+func (d *dateUnmarshaller) Unmarshal(s string) error {
+	t, err := time.ParseInLocation("2006-01-02", s, time.UTC)
+	if err != nil {
+		return err
+	}
+	*d = dateUnmarshaller(t)
+	return nil
+}
+
+func TestParseStructWithUnmarshaler(t *testing.T) {
+	test := func(conf *struct{ TestEnvDate *dateUnmarshaller }) {
+		if assert.NoError(t, envconfig.Init(&conf)) {
+			assert.Equal(t, time.Date(2020, time.June, 20, 0, 0, 0, 0, time.UTC), time.Time(*conf.TestEnvDate))
+		}
+	}
+
+	os.Setenv("TEST_ENV_DATE", "2020-06-20")
+
+	t.Run("val", func(t *testing.T) {
+		conf := struct {
+			TestEnvDate dateUnmarshaller
+		}{}
+		if assert.NoError(t, envconfig.Init(&conf)) {
+			assert.Equal(t, time.Date(2020, time.June, 20, 0, 0, 0, 0, time.UTC), time.Time(conf.TestEnvDate))
+		}
+	})
+
+	t.Run("nil", func(t *testing.T) {
+		test(&struct{ TestEnvDate *dateUnmarshaller }{})
+	})
+
+	t.Run("nonnil", func(t *testing.T) {
+		test(&struct{ TestEnvDate *dateUnmarshaller }{TestEnvDate: new(dateUnmarshaller)})
+	})
+}