Merge pull request #411 from neal/bugfix/unmarshal-unexpected-null

Fix unmarshal null values for non-pointer fields

Author: rvasily

gen/decoder.go

@@ -63,22 +63,34 @@ func (g *Generator) genTypeDecoder(t reflect.Type, out string, tags fieldTags, i
 
 	unmarshalerIface := reflect.TypeOf((*easyjson.Unmarshaler)(nil)).Elem()
 	if reflect.PtrTo(t).Implements(unmarshalerIface) {
-		fmt.Fprintln(g.out, ws+"("+out+").UnmarshalEasyJSON(in)")
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  ("+out+").UnmarshalEasyJSON(in)")
+		fmt.Fprintln(g.out, ws+"}")
 		return nil
 	}
 
 	unmarshalerIface = reflect.TypeOf((*json.Unmarshaler)(nil)).Elem()
 	if reflect.PtrTo(t).Implements(unmarshalerIface) {
-		fmt.Fprintln(g.out, ws+"if data := in.Raw(); in.Ok() {")
-		fmt.Fprintln(g.out, ws+"  in.AddError( ("+out+").UnmarshalJSON(data) )")
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  if data := in.Raw(); in.Ok() {")
+		fmt.Fprintln(g.out, ws+"    in.AddError( ("+out+").UnmarshalJSON(data) )")
+		fmt.Fprintln(g.out, ws+"  }")
 		fmt.Fprintln(g.out, ws+"}")
 		return nil
 	}
 
 	unmarshalerIface = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
 	if reflect.PtrTo(t).Implements(unmarshalerIface) {
-		fmt.Fprintln(g.out, ws+"if data := in.UnsafeBytes(); in.Ok() {")
-		fmt.Fprintln(g.out, ws+"  in.AddError( ("+out+").UnmarshalText(data) )")
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  if data := in.UnsafeBytes(); in.Ok() {")
+		fmt.Fprintln(g.out, ws+"    in.AddError( ("+out+").UnmarshalText(data) )")
+		fmt.Fprintln(g.out, ws+"  }")
 		fmt.Fprintln(g.out, ws+"}")
 		return nil
 	}
@@ -110,13 +122,21 @@ func (g *Generator) genTypeDecoderNoCheck(t reflect.Type, out string, tags field
 	ws := strings.Repeat("  ", indent)
 	// Check whether type is primitive, needs to be done after interface check.
 	if dec := customDecoders[t.String()]; dec != "" {
-		fmt.Fprintln(g.out, ws+out+" = "+dec)
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  "+out+" = "+dec)
+		fmt.Fprintln(g.out, ws+"}")
 		return nil
 	} else if dec := primitiveStringDecoders[t.Kind()]; dec != "" && tags.asString {
 		if tags.intern && t.Kind() == reflect.String {
 			dec = "in.StringIntern()"
 		}
-		fmt.Fprintln(g.out, ws+out+" = "+g.getType(t)+"("+dec+")")
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  "+out+" = "+g.getType(t)+"("+dec+")")
+		fmt.Fprintln(g.out, ws+"}")
 		return nil
 	} else if dec := primitiveDecoders[t.Kind()]; dec != "" {
 		if tags.intern && t.Kind() == reflect.String {
@@ -125,7 +145,11 @@ func (g *Generator) genTypeDecoderNoCheck(t reflect.Type, out string, tags field
 		if tags.noCopy && t.Kind() == reflect.String {
 			dec = "in.UnsafeString()"
 		}
-		fmt.Fprintln(g.out, ws+out+" = "+g.getType(t)+"("+dec+")")
+		fmt.Fprintln(g.out, ws+"if in.IsNull() {")
+		fmt.Fprintln(g.out, ws+"  in.Skip()")
+		fmt.Fprintln(g.out, ws+"} else {")
+		fmt.Fprintln(g.out, ws+"  "+out+" = "+g.getType(t)+"("+dec+")")
+		fmt.Fprintln(g.out, ws+"}")
 		return nil
 	}
 

tests/basic_test.go

@@ -330,14 +330,21 @@ func TestNil(t *testing.T) {
 }
 
 func TestUnmarshalNull(t *testing.T) {
-	p := primitiveTypesValue
+	p := PrimitiveTypes{
+		String: str,
+		Ptr:    &str,
+	}
 
-	data := `{"Ptr":null}`
+	data := `{"String":null,"Ptr":null}`
 
 	if err := easyjson.Unmarshal([]byte(data), &p); err != nil {
 		t.Errorf("easyjson.Unmarshal() error: %v", err)
 	}
 
+	if p.String != str {
+		t.Errorf("Wanted %q, got %q", str, p.String)
+	}
+
 	if p.Ptr != nil {
 		t.Errorf("Wanted nil, got %q", *p.Ptr)
 	}