all: add Unwrap and Is methods to various error types

Add Unwrap methods to types which wrap an underlying error:

  "encodinc/csv".ParseError
  "encoding/json".MarshalerError
  "net/http".transportReadFromServerError
  "net".OpError
  "net".DNSConfigError
  "net/url".Error
  "os/exec".Error
  "signal/internal/pty".PtyError
  "text/template".ExecError

Add os.ErrTemporary. A case could be made for putting this error
value in package net, since no exported error types in package os
include a Temporary method. However, syscall errors returned from
the os package do include this method.

Add Is methods to error types with a Timeout or Temporary method,
making errors.Is(err, os.Err{Timeout,Temporary}) equivalent to
testing the corresponding method:

  "context".DeadlineExceeded
  "internal/poll".TimeoutError
  "net".adrinfoErrno
  "net".OpError
  "net".DNSError
  "net/http".httpError
  "net/http".tlsHandshakeTimeoutError
  "net/pipe".timeoutError
  "net/url".Error

Updates #30322
Updates #29934

Change-Id: I409fb20c072ea39116ebfb8c7534d493483870dc
Reviewed-on: https://go-review.googlesource.com/c/go/+/170037
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
This commit is contained in:
Damien Neil 2019-03-27 08:40:12 -07:00
parent 59ea685ce9
commit 170b8b4b12
18 changed files with 208 additions and 24 deletions

View file

@ -23,6 +23,7 @@ var (
ErrNotExist = errNotExist() // "file does not exist"
ErrClosed = errClosed() // "file already closed"
ErrTimeout = errTimeout() // "deadline exceeded"
ErrTemporary = errTemporary() // "temporary error"
ErrNoDeadline = errNoDeadline() // "file type does not support deadline"
)
@ -32,6 +33,7 @@ func errExist() error { return oserror.ErrExist }
func errNotExist() error { return oserror.ErrNotExist }
func errClosed() error { return oserror.ErrClosed }
func errTimeout() error { return oserror.ErrTimeout }
func errTemporary() error { return oserror.ErrTemporary }
func errNoDeadline() error { return poll.ErrNoDeadline }
type timeout interface {