Merge pull request #64 from alexflint/repeated-unmarshaltext

Fix repeated arguments implementing TextUnmarshaler

parse.go

@@ -159,7 +159,7 @@ func NewParser(config Config, dests ...interface{}) (*Parser, error) {
 			}
 
 			// Check whether this field is supported. It's good to do this here rather than
-			// wait until setScalar because it means that a program with invalid argument
+			// wait until ParseValue because it means that a program with invalid argument
 			// fields will always fail regardless of whether the arguments it received
 			// exercised those fields.
 			var parseable bool
@@ -275,7 +275,7 @@ func process(specs []*spec, args []string) error {
 		}
 		if spec.env != "" {
 			if value, found := os.LookupEnv(spec.env); found {
-				err := setScalar(spec.dest, value)
+				err := scalar.ParseValue(spec.dest, value)
 				if err != nil {
 					return fmt.Errorf("error processing environment variable %s: %v", spec.env, err)
 				}
@@ -355,7 +355,7 @@ func process(specs []*spec, args []string) error {
 			i++
 		}
 
-		err := setScalar(spec.dest, value)
+		err := scalar.ParseValue(spec.dest, value)
 		if err != nil {
 			return fmt.Errorf("error processing %s: %v", arg, err)
 		}
@@ -374,7 +374,7 @@ func process(specs []*spec, args []string) error {
 				}
 				positionals = nil
 			} else if len(positionals) > 0 {
-				err := setScalar(spec.dest, positionals[0])
+				err := scalar.ParseValue(spec.dest, positionals[0])
 				if err != nil {
 					return fmt.Errorf("error processing %s: %v", spec.long, err)
 				}
@@ -426,7 +426,7 @@ func setSlice(dest reflect.Value, values []string, trunc bool) error {
 
 	var ptr bool
 	elem := dest.Type().Elem()
-	if elem.Kind() == reflect.Ptr {
+	if elem.Kind() == reflect.Ptr && !elem.Implements(textUnmarshalerType) {
 		ptr = true
 		elem = elem.Elem()
 	}
@@ -438,7 +438,7 @@ func setSlice(dest reflect.Value, values []string, trunc bool) error {
 
 	for _, s := range values {
 		v := reflect.New(elem)
-		if err := setScalar(v.Elem(), s); err != nil {
+		if err := scalar.ParseValue(v.Elem(), s); err != nil {
 			return err
 		}
 		if !ptr {
@@ -451,7 +451,8 @@ func setSlice(dest reflect.Value, values []string, trunc bool) error {
 
 // canParse returns true if the type can be parsed from a string
 func canParse(t reflect.Type) (parseable, boolean, multiple bool) {
-	parseable, boolean = isScalar(t)
+	parseable = scalar.CanParse(t)
+	boolean = isBoolean(t)
 	if parseable {
 		return
 	}
@@ -466,7 +467,8 @@ func canParse(t reflect.Type) (parseable, boolean, multiple bool) {
 		t = t.Elem()
 	}
 
-	parseable, boolean = isScalar(t)
+	parseable = scalar.CanParse(t)
+	boolean = isBoolean(t)
 	if parseable {
 		return
 	}
@@ -476,7 +478,8 @@ func canParse(t reflect.Type) (parseable, boolean, multiple bool) {
 		t = t.Elem()
 	}
 
-	parseable, boolean = isScalar(t)
+	parseable = scalar.CanParse(t)
+	boolean = isBoolean(t)
 	if parseable {
 		return
 	}
@@ -486,22 +489,16 @@ func canParse(t reflect.Type) (parseable, boolean, multiple bool) {
 
 var textUnmarshalerType = reflect.TypeOf([]encoding.TextUnmarshaler{}).Elem()
 
-// isScalar returns true if the type can be parsed from a single string
+// isBoolean returns true if the type can be parsed from a single string
-func isScalar(t reflect.Type) (parseable, boolean bool) {
+func isBoolean(t reflect.Type) bool {
-	parseable = scalar.CanParse(t)
 	switch {
 	case t.Implements(textUnmarshalerType):
-		return parseable, false
+		return false
 	case t.Kind() == reflect.Bool:
-		return parseable, true
+		return true
 	case t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Bool:
-		return parseable, true
+		return true
 	default:
-		return parseable, false
+		return false
 	}
 }
-
-// set a value from a string
-func setScalar(v reflect.Value, s string) error {
-	return scalar.ParseValue(v, s)
-}

parse_test.go

@@ -599,6 +599,32 @@ func TestTextUnmarshaler(t *testing.T) {
 	assert.Equal(t, 3, args.Foo.val)
 }
 
+func TestRepeatedTextUnmarshaler(t *testing.T) {
+	// fields that implement TextUnmarshaler should be parsed using that interface
+	var args struct {
+		Foo []*textUnmarshaler
+	}
+	err := parse("--foo abc d ef", &args)
+	require.NoError(t, err)
+	require.Len(t, args.Foo, 3)
+	assert.Equal(t, 3, args.Foo[0].val)
+	assert.Equal(t, 1, args.Foo[1].val)
+	assert.Equal(t, 2, args.Foo[2].val)
+}
+
+func TestPositionalTextUnmarshaler(t *testing.T) {
+	// fields that implement TextUnmarshaler should be parsed using that interface
+	var args struct {
+		Foo []*textUnmarshaler `arg:"positional"`
+	}
+	err := parse("abc d ef", &args)
+	require.NoError(t, err)
+	require.Len(t, args.Foo, 3)
+	assert.Equal(t, 3, args.Foo[0].val)
+	assert.Equal(t, 1, args.Foo[1].val)
+	assert.Equal(t, 2, args.Foo[2].val)
+}
+
 type boolUnmarshaler bool
 
 func (p *boolUnmarshaler) UnmarshalText(b []byte) error {