(VDB-68) Verify log block hash matches header block hash

- Delete header on conflict to prompt data refresh (cascade deletes all
  data associated with that block)
- Derive header hash from rpc payload rather than computing it from data
  (prevents hash mismatch between blockchain and cache)

pkg/transformers/test_data/shared_behaviors/repository_behaviors.go

@@ -15,6 +15,7 @@
 package shared_behaviors
 
 import (
+	"github.com/ethereum/go-ethereum/common"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 	"github.com/vulcanize/vulcanizedb/pkg/core"
@@ -23,6 +24,7 @@ import (
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres/repositories"
 	"github.com/vulcanize/vulcanizedb/pkg/fakes"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers/factories"
+	"github.com/vulcanize/vulcanizedb/pkg/transformers/shared"
 	"github.com/vulcanize/vulcanizedb/pkg/transformers/test_data"
 	"github.com/vulcanize/vulcanizedb/test_config"
 	"math/rand"
@@ -101,6 +103,35 @@ func SharedRepositoryCreateBehaviors(inputs *CreateBehaviorInputs) {
 			Expect(err.Error()).To(ContainSubstring("pq: duplicate key value violates unique constraint"))
 		})
 
+		Describe("when log's block hash does not match associated header's block hash", func() {
+			var (
+				differentHeaderID int64
+				err               error
+			)
+
+			BeforeEach(func() {
+				differentHeader := fakes.FakeHeader
+				differentHeader.BlockNumber = fakes.FakeHeader.BlockNumber + 1
+				differentHeader.Hash = common.BytesToHash(append(fakes.FakeHash.Bytes(), 1)).String()
+				differentHeaderID, err = headerRepository.CreateOrUpdateHeader(differentHeader)
+				Expect(err).NotTo(HaveOccurred())
+
+				err = repository.Create(differentHeaderID, []interface{}{logEventModel})
+			})
+
+			It("returns error", func() {
+				Expect(err).To(HaveOccurred())
+				Expect(err).To(MatchError(shared.ErrHeaderMismatch))
+			})
+
+			It("removes header", func() {
+				var headerIDs []int64
+				err = db.Select(&headerIDs, `SELECT id FROM public.headers`)
+				Expect(err).NotTo(HaveOccurred())
+				Expect(headerIDs).NotTo(ContainElement(differentHeaderID))
+			})
+		})
+
 		It("allows for multiple log events of the same type in one transaction if they have different log indexes", func() {
 			err = repository.Create(headerID, []interface{}{logEventModel})
 			Expect(err).NotTo(HaveOccurred())