Dent (#10)

Convert and persist LogNote events as dent records

pkg/transformers/tend/converter.go

@@ -16,37 +16,71 @@ package tend
 
 import (
 	"encoding/json"
+	"errors"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
+
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/shared"
 )
 
 type Converter interface {
 	Convert(contractAddress string, contractAbi string, ethLog types.Log) (TendModel, error)
 }
 
-type TendConverter struct{}
+type TendConverter struct {
+	BidFetcher shared.IBidFetcher
+}
+
+func NewTendConverter() TendConverter {
+	return TendConverter{}
+}
 
 func (c TendConverter) Convert(contractAddress string, contractAbi string, ethLog types.Log) (TendModel, error) {
-	entity := TendModel{}
-	entity.Guy = common.HexToAddress(ethLog.Topics[1].Hex()).String()
-	entity.BidId = ethLog.Topics[2].Big().String()
-	entity.Lot = ethLog.Topics[3].Big().String()
-
-	itemByteLength := 32
-	lastDataItemStartIndex := len(ethLog.Data) - itemByteLength
-	lastItem := ethLog.Data[lastDataItemStartIndex:]
-	last := big.NewInt(0).SetBytes(lastItem)
-	entity.Bid = last.String()
-
-	entity.Tic = "0" //TODO: how do we get the bid tic?
-	entity.TransactionIndex = ethLog.TxIndex
-	rawJson, err := json.Marshal(ethLog)
+	err := validateLog(ethLog)
 	if err != nil {
 		return TendModel{}, err
 	}
 
-	entity.Raw = string(rawJson)
-	return entity, err
+	bidId := ethLog.Topics[2].Big()
+	guy := common.HexToAddress(ethLog.Topics[1].Hex()).String()
+	lot := ethLog.Topics[3].Big().String()
+
+	lastDataItemStartIndex := len(ethLog.Data) - 32
+	lastItem := ethLog.Data[lastDataItemStartIndex:]
+	last := big.NewInt(0).SetBytes(lastItem)
+	bidValue := last.String()
+	tic := "0"
+	//TODO: it is likely that the tic value will need to be added to an emitted event,
+	//so this will need to be updated at that point
+	transactionIndex := ethLog.TxIndex
+
+	rawJson, err := json.Marshal(ethLog)
+	if err != nil {
+		return TendModel{}, err
+	}
+	raw := string(rawJson)
+
+	return TendModel{
+		BidId:            bidId.String(),
+		Lot:              lot,
+		Bid:              bidValue,
+		Guy:              guy,
+		Tic:              tic,
+		TransactionIndex: transactionIndex,
+		Raw:              raw,
+	}, nil
+}
+
+func validateLog(ethLog types.Log) error {
+	if len(ethLog.Data) <= 0 {
+		return errors.New("tend log note data is empty")
+	}
+
+	if len(ethLog.Topics) < 4 {
+		return errors.New("tend log does not contain expected topics")
+	}
+
+	return nil
 }

pkg/transformers/tend/converter_test.go

@@ -18,6 +18,7 @@ import (
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers/shared"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers/tend"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers/test_data"
@@ -27,14 +28,34 @@ var _ = Describe("Tend TendConverter", func() {
 	var converter tend.TendConverter
 
 	BeforeEach(func() {
-		converter = tend.TendConverter{}
+		converter = tend.NewTendConverter()
 	})
 
 	Describe("Convert", func() {
 		It("converts an eth log to a db model", func() {
 			model, err := converter.Convert(shared.FlipperContractAddress, shared.FlipperABI, test_data.TendLogNote)
+
 			Expect(err).NotTo(HaveOccurred())
 			Expect(model).To(Equal(test_data.TendModel))
 		})
+
+		It("returns an error if the log data is empty", func() {
+			emptyDataLog := test_data.TendLogNote
+			emptyDataLog.Data = []byte{}
+			model, err := converter.Convert(shared.FlipperContractAddress, shared.FlipperABI, emptyDataLog)
+
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(MatchError("tend log note data is empty"))
+			Expect(model).To(Equal(tend.TendModel{}))
+		})
+
+		It("returns an error if the expected amount of topics aren't in the log", func() {
+			invalidLog := test_data.TendLogNote
+			invalidLog.Topics = []common.Hash{}
+			model, err := converter.Convert(shared.FlipperContractAddress, shared.FlipperABI, invalidLog)
+
+			Expect(err).To(MatchError("tend log does not contain expected topics"))
+			Expect(model).To(Equal(tend.TendModel{}))
+		})
 	})
 })

pkg/transformers/tend/transformer.go

@@ -36,16 +36,15 @@ type TendTransformerInitializer struct {
 }
 
 func (i TendTransformerInitializer) NewTendTransformer(db *postgres.DB, blockChain core.BlockChain) shared.Transformer {
+	converter := NewTendConverter()
 	fetcher := shared.NewFetcher(blockChain)
 	repository := NewTendRepository(db)
-	transformer := TendTransformer{
+	return TendTransformer{
 		Fetcher:    fetcher,
 		Repository: repository,
-		Converter:  TendConverter{},
+		Converter:  converter,
 		Config:     i.Config,
 	}
-
-	return transformer
 }
 
 func (t TendTransformer) Execute() error {