package light_test import ( "context" "fmt" "io/ioutil" stdlog "log" "os" "testing" "time" dbm "github.com/tendermint/tm-db" "github.com/tendermint/tendermint/abci/example/kvstore" "github.com/tendermint/tendermint/libs/log" "github.com/tendermint/tendermint/light" "github.com/tendermint/tendermint/light/provider" httpp "github.com/tendermint/tendermint/light/provider/http" dbs "github.com/tendermint/tendermint/light/store/db" rpctest "github.com/tendermint/tendermint/rpc/test" ) // Automatically getting new headers and verifying them. func ExampleClient_Update() { // give Tendermint time to generate some blocks time.Sleep(5 * time.Second) dbDir, err := ioutil.TempDir("", "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) } }() time.Sleep(2 * time.Second) h, err := c.Update(context.Background(), time.Now()) if err != nil { stdlog.Fatal(err) } if h != nil && h.Height > 2 { fmt.Println("successful update") } else { fmt.Println("update failed") } // Output: successful update } // Manually getting light blocks and verifying them. func ExampleClient_VerifyLightBlockAtHeight() { // give Tendermint time to generate some blocks time.Sleep(5 * time.Second) dbDir, err := ioutil.TempDir("", "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) if err != nil { stdlog.Fatal(err) } fmt.Println("got header", h.Height) // Output: got header 3 } func TestMain(m *testing.M) { // start a tendermint node (and kvstore) in the background to test against app := kvstore.NewApplication() node := rpctest.StartTendermint(app, rpctest.SuppressStdout) code := m.Run() // and shut down proper at the end rpctest.StopTendermint(node) os.Exit(code) }