[#822] moprh/event: Add parsers from Op struct

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/morph/event/opcodes_test.go

@@ -0,0 +1,82 @@
+package event
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/vm"
+	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBytesFromOpcode(t *testing.T) {
+	tests := [...][]byte{
+		[]byte("test"),
+		[]byte("test test"),
+		[]byte(""),
+		[]byte("1"),
+	}
+
+	bw := io.NewBufBinWriter()
+
+	for _, test := range tests {
+		emit.Bytes(bw.BinWriter, test)
+	}
+
+	var (
+		ctx = vm.NewContext(bw.Bytes())
+
+		op Op
+
+		gotBytes []byte
+		err      error
+	)
+
+	for _, test := range tests {
+		op = getNextOp(ctx)
+
+		gotBytes, err = BytesFromOpcode(op)
+
+		require.NoError(t, err)
+		require.Equal(t, test, gotBytes)
+	}
+}
+
+func TestIntFromOpcode(t *testing.T) {
+	tests := [...]int64{
+		-1,
+		-5,
+		15,
+		16,
+		1_000_000,
+	}
+
+	bw := io.NewBufBinWriter()
+
+	for _, test := range tests {
+		emit.Int(bw.BinWriter, test)
+	}
+
+	var (
+		ctx = vm.NewContext(bw.Bytes())
+
+		op Op
+
+		gotInt int64
+		err    error
+	)
+
+	for _, test := range tests {
+		op = getNextOp(ctx)
+
+		gotInt, err = IntFromOpcode(op)
+
+		require.NoError(t, err)
+		require.Equal(t, test, gotInt)
+	}
+}
+
+func getNextOp(ctx *vm.Context) (op Op) {
+	op.code, op.param, _ = ctx.Next()
+	return
+}