Cleanup fetcher and add test todos

pkg/transformers/shared/log_fetcher.go

@@ -22,25 +22,14 @@ import (
 	"github.com/vulcanize/vulcanizedb/pkg/core"
 )
 
-// TODO Check if Fetcher can be simplified with aggregate logic
-
 type LogFetcher interface {
 	FetchLogs(contractAddresses []common.Address, topics []common.Hash, missingHeader core.Header) ([]types.Log, error)
 }
 
-type SettableLogFetcher interface {
-	LogFetcher
-	SetBC(bc core.BlockChain)
-}
-
 type Fetcher struct {
 	blockChain core.BlockChain
 }
 
-func (fetcher *Fetcher) SetBC(bc core.BlockChain) {
-	fetcher.blockChain = bc
-}
-
 func NewFetcher(blockchain core.BlockChain) Fetcher {
 	return Fetcher{
 		blockChain: blockchain,

pkg/transformers/shared/log_fetcher_test.go

@@ -26,7 +26,14 @@ import (
 )
 
 var _ = Describe("Fetcher", func() {
+	Describe("Iinitialisation", func() {
+		It("creates correct lookup maps", func() {
+
+		})
+	})
+
 	Describe("FetchLogs", func() {
+		// TODO Add tests for aggregate fetching
 		It("fetches logs based on the given query", func() {
 			blockChain := fakes.NewMockBlockChain()
 			fetcher := shared.NewFetcher(blockChain)