Move hashing into subpackage

build/main.go

@@ -8,7 +8,7 @@
 package build
 
 import (
-	"github.com/stellar/go-stellar-base"
+	"github.com/stellar/go-stellar-base/hash"
 	"github.com/stellar/go-stellar-base/xdr"
 )
 
@@ -64,5 +64,5 @@ type Network struct {
 }
 
 func (n *Network) ID() [32]byte {
-	return stellarbase.Hash([]byte(n.Passphrase))
+	return hash.Hash([]byte(n.Passphrase))
 }

build/transaction.go

@@ -5,7 +5,7 @@ import (
 	"encoding/hex"
 	"fmt"
 
-	"github.com/stellar/go-stellar-base"
+	"github.com/stellar/go-stellar-base/hash"
 	"github.com/stellar/go-stellar-base/xdr"
 )
 
@@ -66,7 +66,7 @@ func (b *TransactionBuilder) Hash() ([32]byte, error) {
 		return [32]byte{}, err
 	}
 
-	return stellarbase.Hash(txBytes.Bytes()), nil
+	return hash.Hash(txBytes.Bytes()), nil
 }
 
 // HashHex returns the hex-encoded hash of this builder's transaction

hashing.go → hash/main.go

@@ -1,4 +1,4 @@
-package stellarbase
+package hash
 
 import (
 	"crypto/sha256"

hash/main_test.go

@@ -0,0 +1,38 @@
+package hash
+
+import (
+	"encoding/hex"
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/ginkgo/extensions/table"
+	. "github.com/onsi/gomega"
+)
+
+func TestHash(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Package: github.com/stellar/go-stellar-base/hash")
+}
+
+type HashCase struct {
+	Msg  string
+	Hash string
+}
+
+var _ = DescribeTable("Hash()",
+	func(c HashCase) {
+		sig := Hash([]byte(c.Msg))
+		actual := hex.EncodeToString(sig[:])
+
+		Expect(actual).To(Equal(c.Hash))
+	},
+
+	Entry("hello world", HashCase{
+		"hello world",
+		"b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
+	}),
+	Entry("this is a message", HashCase{
+		"this is a message",
+		"cee86e2a6c441f1e308d16a3db20a8fa8fae2a45730b48ca2c0c61e159af7e78",
+	}),
+)

transaction_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/base64"
 	"fmt"
 
+	"github.com/stellar/go-stellar-base/hash"
 	"github.com/stellar/go-stellar-base/xdr"
 )
 
@@ -69,7 +70,7 @@ func ExampleLowLevelTransaction() {
 		panic(err)
 	}
 
-	txHash := Hash(txBytes.Bytes())
+	txHash := hash.Hash(txBytes.Bytes())
 	signature := spriv.Sign(txHash[:])
 
 	ds := xdr.DecoratedSignature{