persistent node key and ID

p2p/key_test.go

@@ -0,0 +1,49 @@
+package p2p
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	cmn "github.com/tendermint/tmlibs/common"
+)
+
+func TestLoadOrGenNodeKey(t *testing.T) {
+	filePath := filepath.Join(os.TempDir(), cmn.RandStr(12)+"_peer_id.json")
+
+	target := MakePoWTarget(2)
+	nodeKey, err := LoadOrGenNodeKey(filePath, target)
+	assert.Nil(t, err)
+
+	nodeKey2, err := LoadOrGenNodeKey(filePath, target)
+	assert.Nil(t, err)
+
+	assert.Equal(t, nodeKey, nodeKey2)
+}
+
+func repeatBytes(val byte, n int) []byte {
+	return bytes.Repeat([]byte{val}, n)
+}
+
+func TestPoWTarget(t *testing.T) {
+
+	cases := []struct {
+		difficulty uint8
+		target     []byte
+	}{
+		{0, bytes.Repeat([]byte{255}, 20)},
+		{1, append([]byte{128}, repeatBytes(255, 19)...)},
+		{8, append([]byte{0}, repeatBytes(255, 19)...)},
+		{9, append([]byte{0, 128}, repeatBytes(255, 18)...)},
+		{10, append([]byte{0, 64}, repeatBytes(255, 18)...)},
+		{16, append([]byte{0, 0}, repeatBytes(255, 18)...)},
+		{17, append([]byte{0, 0, 128}, repeatBytes(255, 17)...)},
+	}
+
+	for _, c := range cases {
+		assert.Equal(t, MakePoWTarget(c.difficulty), c.target)
+	}
+
+}