light: rename lite2 to light & remove lite (#4946)

This PR removes lite & renames lite2 to light throughout the repo

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

Closes: #4944

light/example_test.go

@@ -0,0 +1,164 @@
+package light_test
+
+import (
+	"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/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)
+	}
+
+	header, err := primary.SignedHeader(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(
+		chainID,
+		light.TrustOptions{
+			Period: 504 * time.Hour, // 21 days
+			Height: 2,
+			Hash:   header.Hash(),
+		},
+		primary,
+		[]provider.Provider{primary}, // NOTE: primary should not be used here
+		dbs.New(db, chainID),
+		// Logger(log.TestingLogger()),
+	)
+	if err != nil {
+		stdlog.Fatal(err)
+	}
+	defer func() {
+		c.Cleanup()
+	}()
+
+	time.Sleep(2 * time.Second)
+
+	// XXX: 30 * time.Minute clock drift is needed because a) Tendermint strips
+	// monotonic component (see types/time/time.go) b) single instance is being
+	// run.
+	// https://github.com/tendermint/tendermint/issues/4489
+	h, err := c.Update(time.Now().Add(30 * time.Minute))
+	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 headers and verifying them.
+func ExampleClient_VerifyHeaderAtHeight() {
+	// 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)
+	}
+
+	header, err := primary.SignedHeader(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(
+		chainID,
+		light.TrustOptions{
+			Period: 504 * time.Hour, // 21 days
+			Height: 2,
+			Hash:   header.Hash(),
+		},
+		primary,
+		[]provider.Provider{primary}, // NOTE: primary should not be used here
+		dbs.New(db, chainID),
+		// Logger(log.TestingLogger()),
+	)
+	if err != nil {
+		stdlog.Fatal(err)
+	}
+	defer func() {
+		c.Cleanup()
+	}()
+
+	_, err = c.VerifyHeaderAtHeight(3, time.Now())
+	if err != nil {
+		stdlog.Fatal(err)
+	}
+
+	h, err := c.TrustedHeader(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)
+}