1package util
 2
 3import (
 4	"fmt"
 5	"io"
 6)
 7
 8type Hash string
 9
10func (h Hash) String() string {
11	return string(h)
12}
13
14func (h *Hash) UnmarshalGQL(v interface{}) error {
15	_, ok := v.(string)
16	if !ok {
17		return fmt.Errorf("labels must be strings")
18	}
19
20	*h = v.(Hash)
21
22	if !h.IsValid() {
23		return fmt.Errorf("invalid hash")
24	}
25
26	return nil
27}
28
29func (h Hash) MarshalGQL(w io.Writer) {
30	w.Write([]byte(`"` + h.String() + `"`))
31}
32
33func (h *Hash) IsValid() bool {
34	if len(*h) != 40 {
35		return false
36	}
37	for _, r := range *h {
38		if (r < 'a' || r > 'z') && (r < '0' || r > '9') {
39			return false
40		}
41	}
42	return true
43}