lbcd/txscript/scriptnum_test.go
Dave Collins fdc2bc867b
txscript: Significantly improve errors.
This converts the majority of script errors from generic errors created
via errors.New and fmt.Errorf to use a concrete type that implements the
error interface with an error code and description.

This allows callers to programmatically detect the type of error via
type assertions and an error code while still allowing the errors to
provide more context.

For example, instead of just having an error the reads "disabled opcode"
as would happen prior to these changes when a disabled opcode is
encountered, the error will now read "attempt to execute disabled opcode
OP_FOO".

While it was previously possible to programmatically detect many errors
due to them being exported, they provided no additional context and
there were also various instances that were just returning errors
created on the spot which callers could not reliably detect without
resorting to looking at the actual error message, which is nearly always
bad practice.

Also, while here, export the MaxStackSize and MaxScriptSize constants
since they can be useful for consumers of the package and perform some
minor cleanup of some of the tests.
2017-01-12 13:12:39 -06:00

274 lines
11 KiB
Go

// Copyright (c) 2015-2017 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package txscript
import (
"bytes"
"encoding/hex"
"testing"
)
// hexToBytes converts the passed hex string into bytes and will panic if there
// is an error. This is only provided for the hard-coded constants so errors in
// the source code can be detected. It will only (and must only) be called with
// hard-coded values.
func hexToBytes(s string) []byte {
b, err := hex.DecodeString(s)
if err != nil {
panic("invalid hex in source file: " + s)
}
return b
}
// TestScriptNumBytes ensures that converting from integral script numbers to
// byte representations works as expected.
func TestScriptNumBytes(t *testing.T) {
t.Parallel()
tests := []struct {
num scriptNum
serialized []byte
}{
{0, nil},
{1, hexToBytes("01")},
{-1, hexToBytes("81")},
{127, hexToBytes("7f")},
{-127, hexToBytes("ff")},
{128, hexToBytes("8000")},
{-128, hexToBytes("8080")},
{129, hexToBytes("8100")},
{-129, hexToBytes("8180")},
{256, hexToBytes("0001")},
{-256, hexToBytes("0081")},
{32767, hexToBytes("ff7f")},
{-32767, hexToBytes("ffff")},
{32768, hexToBytes("008000")},
{-32768, hexToBytes("008080")},
{65535, hexToBytes("ffff00")},
{-65535, hexToBytes("ffff80")},
{524288, hexToBytes("000008")},
{-524288, hexToBytes("000088")},
{7340032, hexToBytes("000070")},
{-7340032, hexToBytes("0000f0")},
{8388608, hexToBytes("00008000")},
{-8388608, hexToBytes("00008080")},
{2147483647, hexToBytes("ffffff7f")},
{-2147483647, hexToBytes("ffffffff")},
// Values that are out of range for data that is interpreted as
// numbers, but are allowed as the result of numeric operations.
{2147483648, hexToBytes("0000008000")},
{-2147483648, hexToBytes("0000008080")},
{2415919104, hexToBytes("0000009000")},
{-2415919104, hexToBytes("0000009080")},
{4294967295, hexToBytes("ffffffff00")},
{-4294967295, hexToBytes("ffffffff80")},
{4294967296, hexToBytes("0000000001")},
{-4294967296, hexToBytes("0000000081")},
{281474976710655, hexToBytes("ffffffffffff00")},
{-281474976710655, hexToBytes("ffffffffffff80")},
{72057594037927935, hexToBytes("ffffffffffffff00")},
{-72057594037927935, hexToBytes("ffffffffffffff80")},
{9223372036854775807, hexToBytes("ffffffffffffff7f")},
{-9223372036854775807, hexToBytes("ffffffffffffffff")},
}
for _, test := range tests {
gotBytes := test.num.Bytes()
if !bytes.Equal(gotBytes, test.serialized) {
t.Errorf("Bytes: did not get expected bytes for %d - "+
"got %x, want %x", test.num, gotBytes,
test.serialized)
continue
}
}
}
// TestMakeScriptNum ensures that converting from byte representations to
// integral script numbers works as expected.
func TestMakeScriptNum(t *testing.T) {
t.Parallel()
// Errors used in the tests below defined here for convenience and to
// keep the horizontal test size shorter.
errNumTooBig := scriptError(ErrNumberTooBig, "")
errMinimalData := scriptError(ErrMinimalData, "")
tests := []struct {
serialized []byte
num scriptNum
numLen int
minimalEncoding bool
err error
}{
// Minimal encoding must reject negative 0.
{hexToBytes("80"), 0, defaultScriptNumLen, true, errMinimalData},
// Minimally encoded valid values with minimal encoding flag.
// Should not error and return expected integral number.
{nil, 0, defaultScriptNumLen, true, nil},
{hexToBytes("01"), 1, defaultScriptNumLen, true, nil},
{hexToBytes("81"), -1, defaultScriptNumLen, true, nil},
{hexToBytes("7f"), 127, defaultScriptNumLen, true, nil},
{hexToBytes("ff"), -127, defaultScriptNumLen, true, nil},
{hexToBytes("8000"), 128, defaultScriptNumLen, true, nil},
{hexToBytes("8080"), -128, defaultScriptNumLen, true, nil},
{hexToBytes("8100"), 129, defaultScriptNumLen, true, nil},
{hexToBytes("8180"), -129, defaultScriptNumLen, true, nil},
{hexToBytes("0001"), 256, defaultScriptNumLen, true, nil},
{hexToBytes("0081"), -256, defaultScriptNumLen, true, nil},
{hexToBytes("ff7f"), 32767, defaultScriptNumLen, true, nil},
{hexToBytes("ffff"), -32767, defaultScriptNumLen, true, nil},
{hexToBytes("008000"), 32768, defaultScriptNumLen, true, nil},
{hexToBytes("008080"), -32768, defaultScriptNumLen, true, nil},
{hexToBytes("ffff00"), 65535, defaultScriptNumLen, true, nil},
{hexToBytes("ffff80"), -65535, defaultScriptNumLen, true, nil},
{hexToBytes("000008"), 524288, defaultScriptNumLen, true, nil},
{hexToBytes("000088"), -524288, defaultScriptNumLen, true, nil},
{hexToBytes("000070"), 7340032, defaultScriptNumLen, true, nil},
{hexToBytes("0000f0"), -7340032, defaultScriptNumLen, true, nil},
{hexToBytes("00008000"), 8388608, defaultScriptNumLen, true, nil},
{hexToBytes("00008080"), -8388608, defaultScriptNumLen, true, nil},
{hexToBytes("ffffff7f"), 2147483647, defaultScriptNumLen, true, nil},
{hexToBytes("ffffffff"), -2147483647, defaultScriptNumLen, true, nil},
{hexToBytes("ffffffff7f"), 549755813887, 5, true, nil},
{hexToBytes("ffffffffff"), -549755813887, 5, true, nil},
{hexToBytes("ffffffffffffff7f"), 9223372036854775807, 8, true, nil},
{hexToBytes("ffffffffffffffff"), -9223372036854775807, 8, true, nil},
{hexToBytes("ffffffffffffffff7f"), -1, 9, true, nil},
{hexToBytes("ffffffffffffffffff"), 1, 9, true, nil},
{hexToBytes("ffffffffffffffffff7f"), -1, 10, true, nil},
{hexToBytes("ffffffffffffffffffff"), 1, 10, true, nil},
// Minimally encoded values that are out of range for data that
// is interpreted as script numbers with the minimal encoding
// flag set. Should error and return 0.
{hexToBytes("0000008000"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("0000008080"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("0000009000"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("0000009080"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffff00"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffff80"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("0000000001"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("0000000081"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffffffff00"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffffffff80"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffffffffff00"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffffffffff80"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffffffffff7f"), 0, defaultScriptNumLen, true, errNumTooBig},
{hexToBytes("ffffffffffffffff"), 0, defaultScriptNumLen, true, errNumTooBig},
// Non-minimally encoded, but otherwise valid values with
// minimal encoding flag. Should error and return 0.
{hexToBytes("00"), 0, defaultScriptNumLen, true, errMinimalData}, // 0
{hexToBytes("0100"), 0, defaultScriptNumLen, true, errMinimalData}, // 1
{hexToBytes("7f00"), 0, defaultScriptNumLen, true, errMinimalData}, // 127
{hexToBytes("800000"), 0, defaultScriptNumLen, true, errMinimalData}, // 128
{hexToBytes("810000"), 0, defaultScriptNumLen, true, errMinimalData}, // 129
{hexToBytes("000100"), 0, defaultScriptNumLen, true, errMinimalData}, // 256
{hexToBytes("ff7f00"), 0, defaultScriptNumLen, true, errMinimalData}, // 32767
{hexToBytes("00800000"), 0, defaultScriptNumLen, true, errMinimalData}, // 32768
{hexToBytes("ffff0000"), 0, defaultScriptNumLen, true, errMinimalData}, // 65535
{hexToBytes("00000800"), 0, defaultScriptNumLen, true, errMinimalData}, // 524288
{hexToBytes("00007000"), 0, defaultScriptNumLen, true, errMinimalData}, // 7340032
{hexToBytes("0009000100"), 0, 5, true, errMinimalData}, // 16779520
// Non-minimally encoded, but otherwise valid values without
// minimal encoding flag. Should not error and return expected
// integral number.
{hexToBytes("00"), 0, defaultScriptNumLen, false, nil},
{hexToBytes("0100"), 1, defaultScriptNumLen, false, nil},
{hexToBytes("7f00"), 127, defaultScriptNumLen, false, nil},
{hexToBytes("800000"), 128, defaultScriptNumLen, false, nil},
{hexToBytes("810000"), 129, defaultScriptNumLen, false, nil},
{hexToBytes("000100"), 256, defaultScriptNumLen, false, nil},
{hexToBytes("ff7f00"), 32767, defaultScriptNumLen, false, nil},
{hexToBytes("00800000"), 32768, defaultScriptNumLen, false, nil},
{hexToBytes("ffff0000"), 65535, defaultScriptNumLen, false, nil},
{hexToBytes("00000800"), 524288, defaultScriptNumLen, false, nil},
{hexToBytes("00007000"), 7340032, defaultScriptNumLen, false, nil},
{hexToBytes("0009000100"), 16779520, 5, false, nil},
}
for _, test := range tests {
// Ensure the error code is of the expected type and the error
// code matches the value specified in the test instance.
gotNum, err := makeScriptNum(test.serialized, test.minimalEncoding,
test.numLen)
if e := tstCheckScriptError(err, test.err); e != nil {
t.Errorf("makeScriptNum(%#x): %v", test.serialized, e)
continue
}
if gotNum != test.num {
t.Errorf("makeScriptNum(%#x): did not get expected "+
"number - got %d, want %d", test.serialized,
gotNum, test.num)
continue
}
}
}
// TestScriptNumInt32 ensures that the Int32 function on script number behaves
// as expected.
func TestScriptNumInt32(t *testing.T) {
t.Parallel()
tests := []struct {
in scriptNum
want int32
}{
// Values inside the valid int32 range are just the values
// themselves cast to an int32.
{0, 0},
{1, 1},
{-1, -1},
{127, 127},
{-127, -127},
{128, 128},
{-128, -128},
{129, 129},
{-129, -129},
{256, 256},
{-256, -256},
{32767, 32767},
{-32767, -32767},
{32768, 32768},
{-32768, -32768},
{65535, 65535},
{-65535, -65535},
{524288, 524288},
{-524288, -524288},
{7340032, 7340032},
{-7340032, -7340032},
{8388608, 8388608},
{-8388608, -8388608},
{2147483647, 2147483647},
{-2147483647, -2147483647},
{-2147483648, -2147483648},
// Values outside of the valid int32 range are limited to int32.
{2147483648, 2147483647},
{-2147483649, -2147483648},
{1152921504606846975, 2147483647},
{-1152921504606846975, -2147483648},
{2305843009213693951, 2147483647},
{-2305843009213693951, -2147483648},
{4611686018427387903, 2147483647},
{-4611686018427387903, -2147483648},
{9223372036854775807, 2147483647},
{-9223372036854775808, -2147483648},
}
for _, test := range tests {
got := test.in.Int32()
if got != test.want {
t.Errorf("Int32: did not get expected value for %d - "+
"got %d, want %d", test.in, got, test.want)
continue
}
}
}