Add cast error checking to refactored transformers

pkg/transformers/vat_init/repository.go

@@ -15,6 +15,7 @@
 package vat_init
 
 import (
+	"fmt"
 	"github.com/vulcanize/vulcanizedb/pkg/core"
 	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
 	"log"
@@ -29,9 +30,14 @@ func (repository VatInitRepository) Create(headerID int64, models []interface{})
 	if err != nil {
 		return err
 	}
-	var vatInit VatInitModel
+
 	for _, model := range models {
-		vatInit = model.(VatInitModel)
+		vatInit, ok := model.(VatInitModel)
+		if !ok {
+			tx.Rollback()
+			return fmt.Errorf("model of type %T, not %T", model, VatInitModel{})
+		}
+
 		log.Printf("VatInit model: %v", vatInit)
 		_, err = tx.Exec(
 			`INSERT INTO maker.vat_init (header_id, ilk, tx_idx, raw_log)

pkg/transformers/vat_init/repository_test.go

@@ -87,6 +87,12 @@ var _ = Describe("Vat init repository", func() {
 			Expect(err).NotTo(HaveOccurred())
 			Expect(headerChecked).To(BeTrue())
 		})
+
+		It("Returns an error if model is of wrong type", func() {
+			err = vatInitRepository.Create(headerID, []interface{}{test_data.WrongModel{}})
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("model of type"))
+		})
 	})
 
 	Describe("MarkHeaderChecked", func() {