Add more tests for Proposal/Vote serialization

String() and Proposal valid after serializing.
To be safe, but mainly to increase test coverage for the PR

types/proposal_test.go

@@ -3,6 +3,10 @@ package types
 import (
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/require"
+
+	wire "github.com/tendermint/go-wire"
 )
 
 var testProposal *Proposal
@@ -31,6 +35,42 @@ func TestProposalSignable(t *testing.T) {
 	}
 }
 
+func TestProposalString(t *testing.T) {
+	str := testProposal.String()
+	expected := `Proposal{12345/23456 111:626C6F636B70 (-1,:0:000000000000) {<nil>} @ 2018-02-11T07:09:22.765Z}`
+	if str != expected {
+		t.Errorf("Got unexpected string for Proposal. Expected:\n%v\nGot:\n%v", expected, str)
+	}
+}
+
+func TestProposalVerifySignature(t *testing.T) {
+	privVal := GenPrivValidatorFS("")
+	pubKey := privVal.GetPubKey()
+
+	prop := NewProposal(4, 2, PartSetHeader{777, []byte("proper")}, 2, BlockID{})
+	signBytes := SignBytes("test_chain_id", prop)
+
+	// sign it
+	signature, err := privVal.Signer.Sign(signBytes)
+	require.NoError(t, err)
+
+	// verify the same proposal
+	valid := pubKey.VerifyBytes(SignBytes("test_chain_id", prop), signature)
+	require.True(t, valid)
+
+	// serialize, deserialize and verify again....
+	newProp := new(Proposal)
+	bs := wire.BinaryBytes(prop)
+	err = wire.ReadBinaryBytes(bs, &newProp)
+	require.NoError(t, err)
+
+	// verify the transmitted proposal
+	newSignBytes := SignBytes("test_chain_id", newProp)
+	require.Equal(t, string(signBytes), string(newSignBytes))
+	valid = pubKey.VerifyBytes(newSignBytes, signature)
+	require.True(t, valid)
+}
+
 func BenchmarkProposalWriteSignBytes(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		SignBytes("test_chain_id", testProposal)