dcrd/txscript/stack_test.go
Dave Collins 6fc98347d9
txscript: Add support for errors.Is/As.
This updates the txscript package to provide support for the errors.Is
and errors.As functions introduced in Go 1.13 per the recently
documented best practices.

The following is an overview of the changes:

- Rename the ErrorCode type to ErrorKind and make it a string
- Implement the error interface on ErrorKind
- Update all error code definitions to the new type
- Remove error code string map that is no longer required
- Remove unused ErrInternal definition
- Change the error code field of the Error type to Err
- Implement Unwrap on the Error type to support unwrapping via
  errors.Is/As
- Remove the IsErrorCode function since it is no longer needed due to
  errors.Is
- Update IsDERSigError to cope with the changes
- Modify various comments to refer to error kinds instead of codes
- Update all test code to use the new ErrorKind directly along with
  errors.Is for detecting the expect errors
- Add full test coverage to ensure the new error definitions work as
  intended
- Update the doc.go errors section accordingly
2020-05-26 21:50:17 -05:00

967 lines
16 KiB
Go

// Copyright (c) 2013-2017 The btcsuite developers
// Copyright (c) 2015-2020 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package txscript
import (
"bytes"
"errors"
"fmt"
"testing"
)
// TestStack tests that all of the stack operations work as expected.
func TestStack(t *testing.T) {
t.Parallel()
tests := []struct {
name string
before [][]byte
operation func(*stack) error
err error
after [][]byte
}{
{
"noop",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
return nil
},
nil,
[][]byte{{1}, {2}, {3}, {4}, {5}},
},
{
"peek underflow (byte)",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
_, err := s.PeekByteArray(5)
return err
},
ErrInvalidStackOperation,
nil,
},
{
"peek underflow (int)",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
_, err := s.PeekInt(5, mathOpCodeMaxScriptNumLen)
return err
},
ErrInvalidStackOperation,
nil,
},
{
"peek underflow (bool)",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
_, err := s.PeekBool(5)
return err
},
ErrInvalidStackOperation,
nil,
},
{
"pop",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
val, err := s.PopByteArray()
if err != nil {
return err
}
if !bytes.Equal(val, []byte{5}) {
return errors.New("not equal")
}
return err
},
nil,
[][]byte{{1}, {2}, {3}, {4}},
},
{
"pop everything",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
for i := 0; i < 5; i++ {
_, err := s.PopByteArray()
if err != nil {
return err
}
}
return nil
},
nil,
nil,
},
{
"pop underflow",
[][]byte{{1}, {2}, {3}, {4}, {5}},
func(s *stack) error {
for i := 0; i < 6; i++ {
_, err := s.PopByteArray()
if err != nil {
return err
}
}
return nil
},
ErrInvalidStackOperation,
nil,
},
{
"pop bool",
[][]byte{nil},
func(s *stack) error {
val, err := s.PopBool()
if err != nil {
return err
}
if val {
return errors.New("unexpected value")
}
return nil
},
nil,
nil,
},
{
"pop bool",
[][]byte{{1}},
func(s *stack) error {
val, err := s.PopBool()
if err != nil {
return err
}
if !val {
return errors.New("unexpected value")
}
return nil
},
nil,
nil,
},
{
"pop bool",
nil,
func(s *stack) error {
_, err := s.PopBool()
return err
},
ErrInvalidStackOperation,
nil,
},
{
"popInt 0",
[][]byte{nil},
func(s *stack) error {
v, err := s.PopInt(mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if v != 0 {
return errors.New("0 != 0 on PopInt")
}
return nil
},
nil,
nil,
},
{
"non-minimal popInt 0",
[][]byte{{0x0}},
func(s *stack) error {
_, err := s.PopInt(mathOpCodeMaxScriptNumLen)
return err
},
ErrMinimalData,
nil,
},
{
"non-minimal popInt -0",
[][]byte{{0x80}},
func(s *stack) error {
_, err := s.PopInt(mathOpCodeMaxScriptNumLen)
return err
},
ErrMinimalData,
nil,
},
{
"popInt 1",
[][]byte{{0x01}},
func(s *stack) error {
v, err := s.PopInt(mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if v != 1 {
return errors.New("1 != 1 on PopInt")
}
return nil
},
nil,
nil,
},
{
"non-minimal popInt 1 leading 0",
[][]byte{{0x01, 0x00, 0x00, 0x00}},
func(s *stack) error {
_, err := s.PopInt(mathOpCodeMaxScriptNumLen)
return err
},
ErrMinimalData,
nil,
},
{
"popInt -1",
[][]byte{{0x81}},
func(s *stack) error {
v, err := s.PopInt(mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if v != -1 {
return errors.New("-1 != -1 on PopInt")
}
return nil
},
nil,
nil,
},
{
"popInt 5 byte",
[][]byte{{0xff, 0xff, 0xff, 0xff, 0x7f}},
func(s *stack) error {
v, err := s.PopInt(5)
if err != nil {
return err
}
if v != 549755813887 {
return fmt.Errorf("%v != 549755813887 on PopInt", v)
}
return nil
},
nil,
nil,
},
{
"non-minimal popInt 5-byte leading 0",
[][]byte{{0xff, 0xff, 0xff, 0x7f, 0x00}},
func(s *stack) error {
_, err := s.PopInt(5)
return err
},
ErrMinimalData,
nil,
},
{
"too big popInt 5-byte leading 0",
[][]byte{{0xff, 0xff, 0xff, 0xff, 0x7f, 0x00}},
func(s *stack) error {
_, err := s.PopInt(5)
return err
},
ErrNumOutOfRange,
nil,
},
// Triggers the multibyte case in asInt
{
"popInt -513",
[][]byte{{0x1, 0x82}},
func(s *stack) error {
v, err := s.PopInt(mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if v != -513 {
fmt.Printf("%v != %v\n", v, -513)
return errors.New("1 != 1 on PopInt")
}
return nil
},
nil,
nil,
},
// Confirm that the asInt code doesn't modify the base data.
{
"peekint nomodify -1",
[][]byte{{0x81}},
func(s *stack) error {
v, err := s.PeekInt(0, mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if v != -1 {
fmt.Printf("%v != %v\n", v, -1)
return errors.New("-1 != -1 on PeekInt")
}
return nil
},
nil,
[][]byte{{0x81}},
},
{
"PushInt 0",
nil,
func(s *stack) error {
s.PushInt(scriptNum(0))
return nil
},
nil,
[][]byte{{}},
},
{
"PushInt 1",
nil,
func(s *stack) error {
s.PushInt(scriptNum(1))
return nil
},
nil,
[][]byte{{0x1}},
},
{
"PushInt -1",
nil,
func(s *stack) error {
s.PushInt(scriptNum(-1))
return nil
},
nil,
[][]byte{{0x81}},
},
{
"PushInt two bytes",
nil,
func(s *stack) error {
s.PushInt(scriptNum(256))
return nil
},
nil,
// little endian.. *sigh*
[][]byte{{0x00, 0x01}},
},
{
"PushInt leading zeros",
nil,
func(s *stack) error {
// this will have the highbit set
s.PushInt(scriptNum(128))
return nil
},
nil,
[][]byte{{0x80, 0x00}},
},
{
"dup",
[][]byte{{1}},
func(s *stack) error {
return s.DupN(1)
},
nil,
[][]byte{{1}, {1}},
},
{
"dup2",
[][]byte{{1}, {2}},
func(s *stack) error {
return s.DupN(2)
},
nil,
[][]byte{{1}, {2}, {1}, {2}},
},
{
"dup3",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.DupN(3)
},
nil,
[][]byte{{1}, {2}, {3}, {1}, {2}, {3}},
},
{
"dup0",
[][]byte{{1}},
func(s *stack) error {
return s.DupN(0)
},
ErrInvalidStackOperation,
nil,
},
{
"dup-1",
[][]byte{{1}},
func(s *stack) error {
return s.DupN(-1)
},
ErrInvalidStackOperation,
nil,
},
{
"dup too much",
[][]byte{{1}},
func(s *stack) error {
return s.DupN(2)
},
ErrInvalidStackOperation,
nil,
},
{
"PushBool true",
nil,
func(s *stack) error {
s.PushBool(true)
return nil
},
nil,
[][]byte{{1}},
},
{
"PushBool false",
nil,
func(s *stack) error {
s.PushBool(false)
return nil
},
nil,
[][]byte{nil},
},
{
"PushBool PopBool",
nil,
func(s *stack) error {
s.PushBool(true)
val, err := s.PopBool()
if err != nil {
return err
}
if !val {
return errors.New("unexpected value")
}
return nil
},
nil,
nil,
},
{
"PushBool PopBool 2",
nil,
func(s *stack) error {
s.PushBool(false)
val, err := s.PopBool()
if err != nil {
return err
}
if val {
return errors.New("unexpected value")
}
return nil
},
nil,
nil,
},
{
"PushInt PopBool",
nil,
func(s *stack) error {
s.PushInt(scriptNum(1))
val, err := s.PopBool()
if err != nil {
return err
}
if !val {
return errors.New("unexpected value")
}
return nil
},
nil,
nil,
},
{
"PushInt PopBool 2",
nil,
func(s *stack) error {
s.PushInt(scriptNum(0))
val, err := s.PopBool()
if err != nil {
return err
}
if val {
return errors.New("unexpected value")
}
return nil
},
nil,
nil,
},
{
"Nip top",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.NipN(0)
},
nil,
[][]byte{{1}, {2}},
},
{
"Nip middle",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.NipN(1)
},
nil,
[][]byte{{1}, {3}},
},
{
"Nip low",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.NipN(2)
},
nil,
[][]byte{{2}, {3}},
},
{
"Nip too much",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
// bite off more than we can chew
return s.NipN(3)
},
ErrInvalidStackOperation,
[][]byte{{2}, {3}},
},
{
"keep on tucking",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.Tuck()
},
nil,
[][]byte{{1}, {3}, {2}, {3}},
},
{
"a little tucked up",
[][]byte{{1}}, // too few arguments for tuck
func(s *stack) error {
return s.Tuck()
},
ErrInvalidStackOperation,
nil,
},
{
"all tucked up",
nil, // too few arguments for tuck
func(s *stack) error {
return s.Tuck()
},
ErrInvalidStackOperation,
nil,
},
{
"drop 1",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.DropN(1)
},
nil,
[][]byte{{1}, {2}, {3}},
},
{
"drop 2",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.DropN(2)
},
nil,
[][]byte{{1}, {2}},
},
{
"drop 3",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.DropN(3)
},
nil,
[][]byte{{1}},
},
{
"drop 4",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.DropN(4)
},
nil,
nil,
},
{
"drop 4/5",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.DropN(5)
},
ErrInvalidStackOperation,
nil,
},
{
"drop invalid",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.DropN(0)
},
ErrInvalidStackOperation,
nil,
},
{
"Rot1",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.RotN(1)
},
nil,
[][]byte{{1}, {3}, {4}, {2}},
},
{
"Rot2",
[][]byte{{1}, {2}, {3}, {4}, {5}, {6}},
func(s *stack) error {
return s.RotN(2)
},
nil,
[][]byte{{3}, {4}, {5}, {6}, {1}, {2}},
},
{
"Rot too little",
[][]byte{{1}, {2}},
func(s *stack) error {
return s.RotN(1)
},
ErrInvalidStackOperation,
nil,
},
{
"Rot0",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.RotN(0)
},
ErrInvalidStackOperation,
nil,
},
{
"Swap1",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.SwapN(1)
},
nil,
[][]byte{{1}, {2}, {4}, {3}},
},
{
"Swap2",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.SwapN(2)
},
nil,
[][]byte{{3}, {4}, {1}, {2}},
},
{
"Swap too little",
[][]byte{{1}},
func(s *stack) error {
return s.SwapN(1)
},
ErrInvalidStackOperation,
nil,
},
{
"Swap0",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.SwapN(0)
},
ErrInvalidStackOperation,
nil,
},
{
"Over1",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.OverN(1)
},
nil,
[][]byte{{1}, {2}, {3}, {4}, {3}},
},
{
"Over2",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.OverN(2)
},
nil,
[][]byte{{1}, {2}, {3}, {4}, {1}, {2}},
},
{
"Over too little",
[][]byte{{1}},
func(s *stack) error {
return s.OverN(1)
},
ErrInvalidStackOperation,
nil,
},
{
"Over0",
[][]byte{{1}, {2}, {3}},
func(s *stack) error {
return s.OverN(0)
},
ErrInvalidStackOperation,
nil,
},
{
"Pick1",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.PickN(1)
},
nil,
[][]byte{{1}, {2}, {3}, {4}, {3}},
},
{
"Pick2",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.PickN(2)
},
nil,
[][]byte{{1}, {2}, {3}, {4}, {2}},
},
{
"Pick too little",
[][]byte{{1}},
func(s *stack) error {
return s.PickN(1)
},
ErrInvalidStackOperation,
nil,
},
{
"Roll1",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.RollN(1)
},
nil,
[][]byte{{1}, {2}, {4}, {3}},
},
{
"Roll2",
[][]byte{{1}, {2}, {3}, {4}},
func(s *stack) error {
return s.RollN(2)
},
nil,
[][]byte{{1}, {3}, {4}, {2}},
},
{
"Roll too little",
[][]byte{{1}},
func(s *stack) error {
return s.RollN(1)
},
ErrInvalidStackOperation,
nil,
},
{
"Peek bool",
[][]byte{{1}},
func(s *stack) error {
// Peek bool is otherwise pretty well tested,
// just check it works.
val, err := s.PeekBool(0)
if err != nil {
return err
}
if !val {
return errors.New("invalid result")
}
return nil
},
nil,
[][]byte{{1}},
},
{
"Peek bool 2",
[][]byte{nil},
func(s *stack) error {
// Peek bool is otherwise pretty well tested,
// just check it works.
val, err := s.PeekBool(0)
if err != nil {
return err
}
if val {
return errors.New("invalid result")
}
return nil
},
nil,
[][]byte{nil},
},
{
"Peek int",
[][]byte{{1}},
func(s *stack) error {
// Peek int is otherwise pretty well tested,
// just check it works.
val, err := s.PeekInt(0, mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if val != 1 {
return errors.New("invalid result")
}
return nil
},
nil,
[][]byte{{1}},
},
{
"Peek int 2",
[][]byte{nil},
func(s *stack) error {
// Peek int is otherwise pretty well tested,
// just check it works.
val, err := s.PeekInt(0, mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if val != 0 {
return errors.New("invalid result")
}
return nil
},
nil,
[][]byte{nil},
},
{
"peekInt 5 byte",
[][]byte{{0xff, 0xff, 0xff, 0xff, 0x7f}, nil},
func(s *stack) error {
v, err := s.PeekInt(1, 5)
if err != nil {
return err
}
if v != 549755813887 {
return fmt.Errorf("%v != 549755813887 on PeekInt", v)
}
return nil
},
nil,
[][]byte{{0xff, 0xff, 0xff, 0xff, 0x7f}, nil},
},
{
"non-minimal peekInt 5-byte leading 0",
[][]byte{{0xff, 0xff, 0xff, 0x7f, 0x00}, nil},
func(s *stack) error {
_, err := s.PeekInt(1, 5)
return err
},
ErrMinimalData,
nil,
},
{
"too big peekInt 5-byte leading 0",
[][]byte{{0xff, 0xff, 0xff, 0xff, 0x7f, 0x00}, nil},
func(s *stack) error {
_, err := s.PeekInt(1, 5)
return err
},
ErrNumOutOfRange,
nil,
},
{
"pop int",
nil,
func(s *stack) error {
s.PushInt(scriptNum(1))
val, err := s.PopInt(mathOpCodeMaxScriptNumLen)
if err != nil {
return err
}
if val != 1 {
return errors.New("invalid result")
}
return nil
},
nil,
nil,
},
{
"pop empty",
nil,
func(s *stack) error {
_, err := s.PopInt(mathOpCodeMaxScriptNumLen)
return err
},
ErrInvalidStackOperation,
nil,
},
}
for _, test := range tests {
// Setup the initial stack state and perform the test operation.
s := stack{}
for i := range test.before {
s.PushByteArray(test.before[i])
}
err := test.operation(&s)
// Ensure the error matches the value specified in the test instance.
if !errors.Is(err, test.err) {
t.Errorf("%s: unexpected error - got %v, want %v", test.name, err,
test.err)
continue
}
if err != nil {
continue
}
// Ensure the resulting stack is the expected length.
if int32(len(test.after)) != s.Depth() {
t.Errorf("%s: stack depth doesn't match expected: %v "+
"vs %v", test.name, len(test.after),
s.Depth())
continue
}
// Ensure all items of the resulting stack are the expected
// values.
for i := range test.after {
val, err := s.PeekByteArray(s.Depth() - int32(i) - 1)
if err != nil {
t.Errorf("%s: can't peek %dth stack entry: %v",
test.name, i, err)
break
}
if !bytes.Equal(val, test.after[i]) {
t.Errorf("%s: %dth stack entry doesn't match "+
"expected: %v vs %v", test.name, i, val,
test.after[i])
break
}
}
}
}