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package errors
import (
"bytes"
"fmt"
"io"
"runtime/debug"
"testing"
)
func TestStackFormatMatches(t *testing.T) {
defer func() {
err := recover()
if err != 'a' {
t.Fatal(err)
}
bs := [][]byte{Errorf("hi").Stack(), debug.Stack()}
// Ignore the first line (as it contains the PC of the .Stack() call)
bs[0] = bytes.SplitN(bs[0], []byte("\n"), 2)[1]
bs[1] = bytes.SplitN(bs[1], []byte("\n"), 2)[1]
if bytes.Compare(bs[0], bs[1]) != 0 {
t.Errorf("Stack didn't match")
t.Errorf("%s", bs[0])
t.Errorf("%s", bs[1])
}
}()
a()
}
func TestSkipWorks(t *testing.T) {
defer func() {
err := recover()
if err != 'a' {
t.Fatal(err)
}
bs := [][]byte{New("hi", 2).Stack(), debug.Stack()}
if !bytes.HasSuffix(bs[1], bs[0]) {
t.Errorf("Stack didn't match")
t.Errorf("%s", bs[0])
t.Errorf("%s", bs[1])
}
}()
a()
}
func TestNewError(t *testing.T) {
e := func() error {
return New("hi", 1)
}()
if e.Error() != "hi" {
t.Errorf("Constructor with a string failed")
}
if New(fmt.Errorf("yo"), 0).Error() != "yo" {
t.Errorf("Constructor with an error failed")
}
if New(e, 0) != e {
t.Errorf("Constructor with an Error failed")
}
if New(nil, 0).Error() != "<nil>" {
t.Errorf("Constructor with nil failed")
}
}
func ExampleErrorf(x int) (int, error) {
if x%2 == 1 {
return 0, Errorf("can only halve even numbers, got %d", x)
}
return x / 2, nil
}
func ExampleNewError() (error, error) {
// Wrap io.EOF with the current stack-trace and return it
return nil, New(io.EOF, 0)
}
func ExampleNewError_skip() {
defer func() {
if err := recover(); err != nil {
// skip 1 frame (the deferred function) and then return the wrapped err
err = New(err, 1)
}
}()
}
func ExampleError_Stack(err Error) {
fmt.Printf("Error: %s\n%s", err.Error(), err.Stack())
}
func a() error {
b(5)
return nil
}
func b(i int) {
c()
}
func c() {
panic('a')
}
|
