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// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package cstruct
import (
"errors"
"fmt"
"io"
"testing"
)
func TestPadBytes(t *testing.T) {
testCases := []struct {
offset int
size int
want int
}{
// No padding at beginning of structure
{0, 1, 0},
{0, 2, 0},
{0, 4, 0},
{0, 8, 0},
// No padding for single bytes
{1, 1, 0},
// Single byte padding
{1, 2, 1},
{3, 4, 1},
// Multi-byte padding
{1, 4, 3},
{2, 8, 6},
}
for _, tc := range testCases {
t.Run(fmt.Sprintf("%d_%d_%d", tc.offset, tc.size, tc.want), func(t *testing.T) {
got := padBytes(tc.offset, tc.size)
if got != tc.want {
t.Errorf("got=%d; want=%d", got, tc.want)
}
})
}
}
func TestDecoder(t *testing.T) {
t.Run("UnsignedTypes", func(t *testing.T) {
dec := func(n int) *Decoder {
buf := make([]byte, n)
buf[0] = 1
d := NewDecoder(buf)
// Use t.Cleanup to perform an assertion on this
// decoder after the test code is finished with it.
t.Cleanup(func() {
if err := d.Err(); err != nil {
t.Fatal(err)
}
})
return d
}
if got := dec(2).Uint16(); got != 1 {
t.Errorf("uint16: got=%d; want=1", got)
}
if got := dec(4).Uint32(); got != 1 {
t.Errorf("uint32: got=%d; want=1", got)
}
if got := dec(8).Uint64(); got != 1 {
t.Errorf("uint64: got=%d; want=1", got)
}
if got := dec(pointerSize / 8).Uintptr(); got != 1 {
t.Errorf("uintptr: got=%d; want=1", got)
}
})
t.Run("SignedTypes", func(t *testing.T) {
dec := func(n int) *Decoder {
// Make a buffer of the exact size that consists of 0xff bytes
buf := make([]byte, n)
for i := range n {
buf[i] = 0xff
}
d := NewDecoder(buf)
// Use t.Cleanup to perform an assertion on this
// decoder after the test code is finished with it.
t.Cleanup(func() {
if err := d.Err(); err != nil {
t.Fatal(err)
}
})
return d
}
if got := dec(2).Int16(); got != -1 {
t.Errorf("int16: got=%d; want=-1", got)
}
if got := dec(4).Int32(); got != -1 {
t.Errorf("int32: got=%d; want=-1", got)
}
if got := dec(8).Int64(); got != -1 {
t.Errorf("int64: got=%d; want=-1", got)
}
})
t.Run("InsufficientData", func(t *testing.T) {
dec := func(n int) *Decoder {
// Make a buffer that's too small and contains arbitrary bytes
buf := make([]byte, n-1)
for i := range n - 1 {
buf[i] = 0xAD
}
// Use t.Cleanup to perform an assertion on this
// decoder after the test code is finished with it.
d := NewDecoder(buf)
t.Cleanup(func() {
if err := d.Err(); err == nil || !errors.Is(err, io.EOF) {
t.Errorf("(n=%d) expected io.EOF; got=%v", n, err)
}
})
return d
}
dec(2).Uint16()
dec(4).Uint32()
dec(8).Uint64()
dec(pointerSize / 8).Uintptr()
dec(2).Int16()
dec(4).Int32()
dec(8).Int64()
})
t.Run("Bytes", func(t *testing.T) {
d := NewDecoder([]byte("hello worldasdf"))
t.Cleanup(func() {
if err := d.Err(); err != nil {
t.Fatal(err)
}
})
buf := make([]byte, 11)
d.Bytes(buf)
if got := string(buf); got != "hello world" {
t.Errorf("bytes: got=%q; want=%q", got, "hello world")
}
})
}
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