composeAndExecute command that loads and executes over arbitrary transformer set exported from a go plugin generated according to config file; test for plugin generation, loading, and execution; work on plugins README

libraries/shared/transformer/transformer.go

@@ -0,0 +1,46 @@
+// Auto-gen this code for different transformer interfaces/configs
+// based on config file to allow for more modularity
+
+package transformer
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/vulcanize/vulcanizedb/pkg/core"
+
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/shared/constants"
+)
+
+type Transformer interface {
+	Execute(logs []types.Log, header core.Header, recheckHeaders constants.TransformerExecution) error
+	GetConfig() TransformerConfig
+}
+
+type TransformerInitializer func(db *postgres.DB) Transformer
+
+type TransformerConfig struct {
+	TransformerName     string
+	ContractAddresses   []string
+	ContractAbi         string
+	Topic               string
+	StartingBlockNumber int64
+	EndingBlockNumber   int64 // Set -1 for indefinite transformer
+}
+
+func HexToInt64(byteString string) int64 {
+	value := common.HexToHash(byteString)
+	return value.Big().Int64()
+}
+
+func HexToString(byteString string) string {
+	value := common.HexToHash(byteString)
+	return value.Big().String()
+}
+
+func HexStringsToAddresses(strings []string) (addresses []common.Address) {
+	for _, hexString := range strings {
+		addresses = append(addresses, common.HexToAddress(hexString))
+	}
+	return
+}

libraries/shared/transformer/transformer_suite_test.go

@@ -0,0 +1,35 @@
+// VulcanizeDB
+// Copyright © 2018 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package transformer_test
+
+import (
+	"io/ioutil"
+	"log"
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestShared(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Shared Transformer Suite")
+}
+
+var _ = BeforeSuite(func() {
+	log.SetOutput(ioutil.Discard)
+})

libraries/shared/transformer/transformer_test.go

@@ -0,0 +1,17 @@
+// VulcanizeDB
+// Copyright © 2018 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package transformer_test