initial test for prepare proposal

internal/state/execution_test.go

@@ -566,6 +566,35 @@ func TestFinalizeBlockValidatorUpdatesResultingInEmptySet(t *testing.T) {
 	assert.NotEmpty(t, state.NextValidators.Validators)
 }
 
+func TestEmptyPrepareProposal(t *testing.T) {
+	const height = 2
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	app := abcimocks.NewBaseMock()
+	cc := abciclient.NewLocalCreator(app)
+	logger := log.TestingLogger()
+	proxyApp := proxy.NewAppConns(cc, logger, proxy.NopMetrics())
+	err := proxyApp.Start(ctx)
+	require.NoError(t, err)
+
+	state, stateDB, privVals := makeState(t, 1, height)
+	stateStore := sm.NewStore(stateDB)
+
+	blockExec := sm.NewBlockExecutor(
+		stateStore,
+		logger,
+		proxyApp.Consensus(),
+		mmock.Mempool{},
+		sm.EmptyEvidencePool{},
+		nil,
+	)
+	pa, _ := state.Validators.GetByIndex(0)
+	commit := makeValidCommit(ctx, t, height, types.BlockID{}, state.Validators, privVals)
+	_, err = blockExec.CreateProposalBlock(ctx, height, state, commit, pa, nil)
+	require.NoError(t, err)
+}
+
 func makeBlockID(hash []byte, partSetSize uint32, partSetHash []byte) types.BlockID {
 	var (
 		h   = make([]byte, tmhash.Size)