types: add tests for blockmeta (#5013)

## Description

add tests for to/from proto for blockmeta and add validate basic test case.

Closes: #XXX

types/block_meta_test.go

@@ -1,7 +1,94 @@
 package types
 
-import "testing"
+import (
+	"testing"
 
-func TestBlockMetaValidateBasic(t *testing.T) {
-	// TODO
+	"github.com/stretchr/testify/require"
+	"github.com/tendermint/tendermint/crypto/tmhash"
+	tmrand "github.com/tendermint/tendermint/libs/rand"
+)
+
+func TestBlockMeta_ToProto(t *testing.T) {
+	h := makeRandHeader()
+	bi := BlockID{Hash: h.Hash(), PartsHeader: PartSetHeader{Total: 123, Hash: tmrand.Bytes(tmhash.Size)}}
+
+	bm := &BlockMeta{
+		BlockID:   bi,
+		BlockSize: 200,
+		Header:    h,
+		NumTxs:    0,
+	}
+
+	tests := []struct {
+		testName string
+		bm       *BlockMeta
+		expErr   bool
+	}{
+		{"success", bm, false},
+		{"failure nil", nil, true},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.testName, func(t *testing.T) {
+			pb := tt.bm.ToProto()
+
+			bm, err := BlockMetaFromProto(pb)
+
+			if !tt.expErr {
+				require.NoError(t, err, tt.testName)
+				require.Equal(t, tt.bm, bm, tt.testName)
+			} else {
+				require.Error(t, err, tt.testName)
+			}
+		})
+	}
+}
+
+func TestBlockMeta_ValidateBasic(t *testing.T) {
+	h := makeRandHeader()
+	bi := BlockID{Hash: h.Hash(), PartsHeader: PartSetHeader{Total: 123, Hash: tmrand.Bytes(tmhash.Size)}}
+	bi2 := BlockID{Hash: tmrand.Bytes(tmhash.Size),
+		PartsHeader: PartSetHeader{Total: 123, Hash: tmrand.Bytes(tmhash.Size)}}
+	bi3 := BlockID{Hash: []byte("incorrect hash"),
+		PartsHeader: PartSetHeader{Total: 123, Hash: []byte("incorrect hash")}}
+
+	bm := &BlockMeta{
+		BlockID:   bi,
+		BlockSize: 200,
+		Header:    h,
+		NumTxs:    0,
+	}
+
+	bm2 := &BlockMeta{
+		BlockID:   bi2,
+		BlockSize: 200,
+		Header:    h,
+		NumTxs:    0,
+	}
+
+	bm3 := &BlockMeta{
+		BlockID:   bi3,
+		BlockSize: 200,
+		Header:    h,
+		NumTxs:    0,
+	}
+
+	tests := []struct {
+		name    string
+		bm      *BlockMeta
+		wantErr bool
+	}{
+		{"success", bm, false},
+		{"failure wrong blockID hash", bm2, true},
+		{"failure wrong length blockID hash", bm3, true},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.bm.ValidateBasic(); (err != nil) != tt.wantErr {
+				t.Errorf("BlockMeta.ValidateBasic() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
 }