Allow users to watch and print summaries for contracts

pkg/repositories/in_memory.go

@@ -19,6 +19,10 @@ func (repository *InMemory) IsWatchedContract(contractHash string) bool {
 	return present
 }
 
+func (repository *InMemory) FindWatchedContract(contractHash string) *core.WatchedContract {
+	return repository.watchedContracts[contractHash]
+}
+
 func (repository *InMemory) MissingBlockNumbers(startingBlockNumber int64, endingBlockNumber int64) []int64 {
 	missingNumbers := []int64{}
 	for blockNumber := int64(startingBlockNumber); blockNumber <= endingBlockNumber; blockNumber++ {

pkg/repositories/postgres.go

@@ -50,6 +50,23 @@ func (repository Postgres) IsWatchedContract(contractHash string) bool {
 	return exists
 }
 
+func (repository Postgres) FindWatchedContract(contractHash string) *core.WatchedContract {
+	var savedContracts []core.WatchedContract
+	contractRows, _ := repository.Db.Query(
+		`select contract_hash from watched_contracts where contract_hash=$1`, contractHash)
+	for contractRows.Next() {
+		var savedContractHash string
+		contractRows.Scan(&savedContractHash)
+		savedContract := core.WatchedContract{Hash: savedContractHash}
+		savedContracts = append(savedContracts, savedContract)
+	}
+	if len(savedContracts) > 0 {
+		return &savedContracts[0]
+	} else {
+		return nil
+	}
+}
+
 func (repository Postgres) MaxBlockNumber() int64 {
 	var highestBlockNumber int64
 	repository.Db.Get(&highestBlockNumber, `SELECT MAX(block_number) FROM blocks`)

pkg/repositories/repository.go

@@ -10,4 +10,5 @@ type Repository interface {
 	MissingBlockNumbers(startingBlockNumber int64, endingBlockNumber int64) []int64
 	CreateWatchedContract(contract core.WatchedContract) error
 	IsWatchedContract(contractHash string) bool
+	FindWatchedContract(contractHash string) *core.WatchedContract
 }

pkg/repositories/repository_test.go

@@ -194,14 +194,6 @@ var _ = Describe("Repositories", func() {
 
 				Expect(repository.MissingBlockNumbers(1, 5)).To(Equal([]int64{1, 2, 4, 5}))
 			})
-
-			It("Adds a contract to the watched_contracts table", func() {
-				repository.CreateWatchedContract(core.WatchedContract{Hash: "x123"})
-
-				Expect(repository.IsWatchedContract("x123")).To(BeTrue())
-				Expect(repository.IsWatchedContract("x456")).To(BeFalse())
-			})
-
 		})
 
 		Describe("The max block numbers", func() {
@@ -218,6 +210,24 @@ var _ = Describe("Repositories", func() {
 				Expect(repository.MaxBlockNumber()).To(Equal(int64(10)))
 			})
 		})
+
+		Describe("Creating watched contracts", func() {
+			It("returns the watched contract when it exists", func() {
+				repository.CreateWatchedContract(core.WatchedContract{Hash: "x123"})
+
+				watchedContract := repository.FindWatchedContract("x123")
+				Expect(watchedContract).NotTo(BeNil())
+				Expect(watchedContract.Hash).To(Equal("x123"))
+
+				Expect(repository.IsWatchedContract("x123")).To(BeTrue())
+				Expect(repository.IsWatchedContract("x456")).To(BeFalse())
+			})
+
+			It("returns nil if contract does not exist", func() {
+				watchedContract := repository.FindWatchedContract("x123")
+				Expect(watchedContract).To(BeNil())
+			})
+		})
 	}
 
 	Describe("In memory repository", func() {

pkg/repositories/testing/helpers.go

@@ -3,6 +3,7 @@ package testing
 import "github.com/8thlight/vulcanizedb/pkg/repositories"
 
 func ClearData(postgres repositories.Postgres) {
+	postgres.Db.MustExec("DELETE FROM watched_contracts")
 	postgres.Db.MustExec("DELETE FROM transactions")
 	postgres.Db.MustExec("DELETE FROM blocks")
 }