Add mock EthClient for testing

README.md

@@ -17,5 +17,5 @@ POSTGRES_PASS=yourpasswordhere go test ./...
 - Install [golangci-lint](https://golangci-lint.run)
 - Once installed, to check the lints
 ```
-golangci-lint run --timeout=5m -E whitespace -E gosec -E gci -E misspell -E gomnd --max-same-issues 0
+golangci-lint run --timeout=5m -E whitespace -E gosec -E gci -E misspell -E gomnd -E gofmt -E goimports -E golint --exclude-use-default=false --max-same-issues 0
 ```

coordinator/coordinator.go

@@ -40,7 +40,7 @@ type Coordinator struct {
 	txsel        *txselector.TxSelector
 	batchBuilder *batchbuilder.BatchBuilder
 
-	ethClient  *eth.Client
+	ethClient  eth.ClientInterface
 	ethTxStore kvdb.Storage
 }
 

eth/client_test.go

@@ -0,0 +1,14 @@
+package eth
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestClientInterface(t *testing.T) {
+	var c ClientInterface
+	client := NewClient(nil, nil, nil, nil)
+	c = client
+	require.NotNil(t, c)
+}

eth/interface.go

@@ -0,0 +1,18 @@
+package eth
+
+import (
+	"context"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/hermeznetwork/hermez-node/common"
+)
+
+// ClientInterface is the eth Client interface used by hermez-node modules to
+// interact with Ethereum Blockchain and smart contracts.
+type ClientInterface interface {
+	CurrentBlock() (*big.Int, error)
+	HeaderByNumber(context.Context, *big.Int) (*types.Header, error)
+	BlockByNumber(context.Context, *big.Int) (*common.Block, error)
+	ForgeCall(*common.CallDataForge) ([]byte, error)
+}

test/ethclient.go

@@ -0,0 +1,79 @@
+package test
+
+import (
+	"context"
+	"math/big"
+	"time"
+
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/hermeznetwork/hermez-node/common"
+	"github.com/hermeznetwork/hermez-node/log"
+)
+
+// Client implements the eth.IClient interface, allowing to manipulate the
+// values for testing, working with deterministic results.
+type Client struct {
+	log      bool
+	blockNum *big.Int
+}
+
+// NewTestEthClient returns a new test Client that implements the eth.IClient
+// interface, at the given initialBlockNumber.
+func NewTestEthClient(l bool, initialBlockNumber int64) *Client {
+	return &Client{
+		log:      l,
+		blockNum: big.NewInt(initialBlockNumber),
+	}
+}
+
+// Advance moves one block forward
+func (c *Client) Advance() {
+	c.blockNum = c.blockNum.Add(c.blockNum, big.NewInt(1))
+	if c.log {
+		log.Debugf("TestEthClient blockNum advanced: %d", c.blockNum)
+	}
+}
+
+// SetBlockNum sets the Client.blockNum to the given blockNum
+func (c *Client) SetBlockNum(blockNum *big.Int) {
+	c.blockNum = blockNum
+	if c.log {
+		log.Debugf("TestEthClient blockNum set to: %d", c.blockNum)
+	}
+}
+
+// CurrentBlock returns the current blockNum
+func (c *Client) CurrentBlock() (*big.Int, error) {
+	return c.blockNum, nil
+}
+
+func newHeader(number *big.Int) *types.Header {
+	return &types.Header{
+		Number: number,
+		Time:   uint64(number.Int64()),
+	}
+}
+
+// HeaderByNumber returns the *types.Header for the given block number in a
+// deterministic way.
+func (c *Client) HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) {
+	return newHeader(number), nil
+}
+
+// BlockByNumber returns the *common.Block for the given block number in a
+// deterministic way.
+func (c *Client) BlockByNumber(ctx context.Context, number *big.Int) (*common.Block, error) {
+	header := newHeader(number)
+
+	return &common.Block{
+		EthBlockNum: uint64(number.Int64()),
+		Timestamp:   time.Unix(number.Int64(), 0),
+		Hash:        header.Hash(),
+	}, nil
+}
+
+// ForgeCall send the *common.CallDataForge to the Forge method of the mock
+// smart contract
+func (c *Client) ForgeCall(*common.CallDataForge) ([]byte, error) {
+	return nil, nil
+}

test/ethclient_test.go

@@ -0,0 +1,46 @@
+package test
+
+import (
+	"context"
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/hermeznetwork/hermez-node/eth"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestClientInterface(t *testing.T) {
+	var c eth.ClientInterface
+	client := NewTestEthClient(true, 1000)
+	c = client
+	require.NotNil(t, c)
+}
+
+func TestEthClient(t *testing.T) {
+	c := NewTestEthClient(true, 1000)
+
+	block, err := c.BlockByNumber(context.TODO(), big.NewInt(3))
+	assert.Nil(t, err)
+	assert.Equal(t, uint64(3), block.EthBlockNum)
+	assert.Equal(t, time.Unix(3, 0), block.Timestamp)
+	assert.Equal(t, "0x6b0ab5a7a0ebf5f05cef3b49bc7a9739de06469a4e05557d802ee828fdf5187e", block.Hash.Hex())
+
+	header, err := c.HeaderByNumber(context.TODO(), big.NewInt(4))
+	assert.Nil(t, err)
+	assert.Equal(t, big.NewInt(4), header.Number)
+	assert.Equal(t, uint64(4), header.Time)
+	assert.Equal(t, "0x66cdb12322040a5a345ad29cea66ca97c14d6142b53987010947c8c008e26913", header.Hash().Hex())
+
+	assert.Equal(t, big.NewInt(1000), c.blockNum)
+	c.Advance()
+	assert.Equal(t, big.NewInt(1001), c.blockNum)
+	c.Advance()
+	assert.Equal(t, big.NewInt(1002), c.blockNum)
+
+	c.SetBlockNum(big.NewInt(5000))
+	assert.Equal(t, big.NewInt(5000), c.blockNum)
+	c.Advance()
+	assert.Equal(t, big.NewInt(5001), c.blockNum)
+}