veto_no_event_filetest.gno

 1// PKGPATH: gno.land/r/demo/grc721veto
 2
 3// Extension hooks run before the Transfer event is emitted, so a hook that vetoes
 4// a movement leaves nothing on the event stream. Only the second mint, which no
 5// hook refuses, is announced.
 6package grc721veto
 7
 8import (
 9	"gno.land/p/nt/grc721/v0"
10)
11
12type vetoExtension struct {
13	refuse grc721.TokenID
14}
15
16func (e *vetoExtension) ExtensionKind() string { return "veto" }
17
18func (e *vetoExtension) OnMint(to address, tid grc721.TokenID) {
19	if tid == e.refuse {
20		panic("veto: mint refused")
21	}
22}
23
24func (e *vetoExtension) OnTransfer(from, to address, tid grc721.TokenID) {}
25
26func (e *vetoExtension) OnBurn(tid grc721.TokenID) {}
27
28func main(cur realm) {
29	_, ledger := grc721.NewToken("Veto", "VETO", 0, cur)
30	ledger.RegisterExtension(&vetoExtension{refuse: "1"})
31
32	func() {
33		defer func() { println("recovered:", recover()) }()
34		ledger.Mint(cur.Address(), "1")
35	}()
36
37	ledger.Mint(cur.Address(), "2")
38}
39
40// Output:
41// recovered: veto: mint refused
42
43// Events:
44// [
45//   {
46//     "type": "NewToken",
47//     "attrs": [
48//       {
49//         "key": "token",
50//         "value": "gno.land/r/demo/grc721veto.VETO.0000000"
51//       },
52//       {
53//         "key": "name",
54//         "value": "Veto"
55//       },
56//       {
57//         "key": "symbol",
58//         "value": "VETO"
59//       }
60//     ],
61//     "pkg_path": "gno.land/p/nt/grc721/v0"
62//   },
63//   {
64//     "type": "Transfer",
65//     "attrs": [
66//       {
67//         "key": "token",
68//         "value": "gno.land/r/demo/grc721veto.VETO.0000000"
69//       },
70//       {
71//         "key": "from",
72//         "value": ""
73//       },
74//       {
75//         "key": "to",
76//         "value": "g1dywcn8v2jdpl6fuks8tw3l8gnzer0hv8mfkraa"
77//       },
78//       {
79//         "key": "tokenId",
80//         "value": "2"
81//       }
82//     ],
83//     "pkg_path": "gno.land/p/nt/grc721/v0"
84//   }
85// ]