Synchronizer main loop & reorg (#82)

* Synchronizer

* mend

Synchronizer main loop & reorg

* mend

Synchronizer main loop & reorg

* mend

Synchronizer main loop & reorg

* Update PR and apply small changes

Update PR and apply small changes:
- Remove arbitrary line jumps (for example after an `err:=` there are cases with extra line before error check, and there are cases without the extra jumpline. Another example is the empty lines between a comment and the line of comment that is explained)
- Fix some typo
- Fix value printing of `lastSavedBlock` instead of `latestBlockNum`
- Uncomment parameters of structs and use linter syntax to avoid unused checks

* Update Synchr after master-pull to last types to compile

Co-authored-by: Toni Ramírez <toni@iden3.com>
Co-authored-by: arnaucube <root@arnaucube.com>

synchronizer/synchronizer_test.go

@@ -0,0 +1,72 @@
+package synchronizer
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/hermeznetwork/hermez-node/db/historydb"
+	"github.com/hermeznetwork/hermez-node/db/statedb"
+	"github.com/hermeznetwork/hermez-node/eth"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test(t *testing.T) {
+	// Int State DB
+	dir, err := ioutil.TempDir("", "tmpdb")
+	require.Nil(t, err)
+
+	sdb, err := statedb.NewStateDB(dir, true, 32)
+	assert.Nil(t, err)
+
+	// Init History DB
+	pass := os.Getenv("POSTGRES_PASS")
+	historyDB, err := historydb.NewHistoryDB(5432, "localhost", "hermez", pass, "history")
+	require.Nil(t, err)
+	err = historyDB.Reorg(0)
+	assert.Nil(t, err)
+
+	// Init eth client
+	ehtClientDialURL := os.Getenv("ETHCLIENT_DIAL_URL")
+	ethClient, err := ethclient.Dial(ehtClientDialURL)
+	require.Nil(t, err)
+
+	client := eth.NewClient(ethClient, nil, nil, nil)
+
+	// Create Synchronizer
+	s := NewSynchronizer(client, historyDB, sdb)
+
+	// Test Sync
+	err = s.Sync()
+	require.Nil(t, err)
+
+	// TODO: Reorg will be properly tested once we have the mock ethClient implemented
+	/*
+		// Force a Reorg
+		lastSavedBlock, err := historyDB.GetLastBlock()
+		require.Nil(t, err)
+
+		lastSavedBlock.EthBlockNum++
+		err = historyDB.AddBlock(lastSavedBlock)
+		require.Nil(t, err)
+
+		lastSavedBlock.EthBlockNum++
+		err = historyDB.AddBlock(lastSavedBlock)
+		require.Nil(t, err)
+
+		log.Debugf("Wait for the blockchain to generate some blocks...")
+		time.Sleep(40 * time.Second)
+
+
+		err = s.Sync()
+		require.Nil(t, err)
+	*/
+
+	// Close History DB
+	if err := historyDB.Close(); err != nil {
+		fmt.Println("Error closing the history DB:", err)
+	}
+}