Function ExampleClient_VerifyLightBlockAtHeight

light/example_test.go:92–156

Manually getting light blocks and verifying them.

()

// Manually getting light blocks and verifying them.
func ExampleClient_VerifyLightBlockAtHeight() {
	// give Tendermint time to generate some blocks
	time.Sleep(5 * time.Second)

	dbDir, err := os.MkdirTemp("", "light-client-example")
	if err != nil {
		stdlog.Fatal(err)
	}
	defer os.RemoveAll(dbDir)

	var (
		config  = rpctest.GetConfig()
		chainID = config.ChainID()
	)

	primary, err := httpp.New(chainID, config.RPC.ListenAddress)
	if err != nil {
		stdlog.Fatal(err)
	}

	block, err := primary.LightBlock(context.Background(), 2)
	if err != nil {
		stdlog.Fatal(err)
	}

	db, err := dbm.NewGoLevelDB("light-client-db", dbDir)
	if err != nil {
		stdlog.Fatal(err)
	}

	c, err := light.NewClient(
		context.Background(),
		chainID,
		light.TrustOptions{
			Period: 504 * time.Hour, // 21 days
			Height: 2,
			Hash:   block.Hash(),
		},
		primary,
		[]provider.Provider{primary}, // NOTE: primary should not be used here
		dbs.New(db, chainID),
		light.Logger(log.TestingLogger()),
	)
	if err != nil {
		stdlog.Fatal(err)
	}
	defer func() {
		if err := c.Cleanup(); err != nil {
			stdlog.Fatal(err)
		}
	}()

	_, err = c.VerifyLightBlockAtHeight(context.Background(), 3, time.Now())
	if err != nil {
		stdlog.Fatal(err)
	}

	h, err := c.TrustedLightBlock(3)