json.Unmarshaler interface not considered for nested types #93
Description
I believe I may have found a false positive. The following minimum reproduction shows the false positive:
package main
import (
"encoding/json"
"fmt"
)
type Outer struct {
Inner Inner `json:"inner"`
}
type Inner struct {
String string
}
func (i *Inner) UnmarshalJSON(p []byte) error {
var s string
if err := json.Unmarshal(p, &s); err != nil {
return err
}
i.String = s
return nil
}
func main() {
buf := []byte(`
{
"inner": "my string"
}
`)
var outer Outer
if err := json.Unmarshal(buf, &outer); err != nil {
panic(err)
}
fmt.Println(outer)
}
The output of the program is:
{{my string}}
See https://go.dev/play/p/HEcyBYmfO_Y
However, musttag with the latest tag (v0.12.1) shows a false positive:
main.go:32:32: the given struct should be annotated with the `json` tag
It doesn't seem to ignore the absence of JSON tags on the Inner type, even though the Inner type implements the jsonUnmarshaler interface.