Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Wrap EOF error instead of replacing it #777

Closed
wants to merge 1 commit into from
Closed

Wrap EOF error instead of replacing it #777

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 1 addition & 2 deletions client_ext_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -270,8 +270,7 @@ func TestConnectionDropped(t *testing.T) {
}
err = svrStream.Err()
}
assert.NotNil(t, err)
if !assert.Equal(t, connect.CodeOf(err), connect.CodeUnavailable) {
if assert.NotNil(t, err) && !assert.Equal(t, connect.CodeOf(err), connect.CodeUnavailable) {
t.Logf("err = %v\n%#v", err, err)
}
})
Expand Down
6 changes: 1 addition & 5 deletions duplex_http_call.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -306,11 +306,7 @@ func (d *duplexHTTPCall) makeRequest() {
// pipe. Write's check for io.ErrClosedPipe and will convert this to io.EOF.
response, err := d.httpClient.Do(d.request) //nolint:bodyclose
if err != nil {
if errors.Is(err, io.EOF) {
// We use io.EOF as a sentinel in many places and don't want this
// transport error to be confused for those other situations.
err = io.ErrUnexpectedEOF
}
err = wrapIfEOF(err)
err = wrapIfContextError(err)
err = wrapIfLikelyH2CNotConfiguredError(d.request, err)
err = wrapIfLikelyWithGRPCNotUsedError(err)
Expand Down
30 changes: 30 additions & 0 deletions error.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ import (
"context"
"errors"
"fmt"
"io"
"net/http"
"net/url"
"os"
Expand Down Expand Up @@ -256,6 +257,22 @@ func (e *Error) detailsAsAny() []*anypb.Any {
return anys
}

type unexpectedEOFError struct {
err error
}

func (e *unexpectedEOFError) Error() string {
return e.err.Error()
}

func (e *unexpectedEOFError) Is(err error) bool {
// Return true only if err is the same value as e or if err
// is io.ErrUnexpectedEOF. Importantly, this returns false if
// the given err is io.EOF.
unexpectedEOF, ok := err.(*unexpectedEOFError)
return errors.Is(err, io.ErrUnexpectedEOF) || ok && e == unexpectedEOF
}

// IsNotModifiedError checks whether the supplied error indicates that the
// requested resource hasn't changed. It only returns true if the server used
// [NewNotModifiedError] in response to a Connect-protocol RPC made with an
Expand Down Expand Up @@ -292,6 +309,19 @@ func wrapIfUncoded(err error) error {
return NewError(CodeUnknown, maybeCodedErr)
}

// wrapIfEOF is used for abnormal EOF conditions, like EOF before response
// headers were received. When this happens, we want errors.Is(err, io.EOF) to
// return false (since we have *many* tests for io.EOF, which otherwise
// indicates a normal end of stream). Instead, the error will return true with
// errors.Is(err, io.ErrUnexpectedEOF), to make it more clear that the EOF is
// an abnormal end of the operation.
func wrapIfEOF(err error) error {
if errors.Is(err, io.EOF) {
return &unexpectedEOFError{err}
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't think this needs to be a custom error. NewError(CodeUnavailable, err) seems fine.

Copy link
Member Author

@jhump jhump Sep 17, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

No, that doesn't work at all. In fact, that's what the code already does. If you leave that wrapping in place and remove this one, the tests (added in #776) will fail with a mix of "unimplemented" and "unknown" error codes, instead of "unavailable".

I wrote long-ish comments trying to explain why this is needed. Were they unclear?

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Sorry I meant to translate the error but still wrap as a connect-go:

NewError(CodeUnavailable, io.ErrUnexpectedEOF)

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Well, that's basically what the other PR did -- it replaced the error instead of wrapping it.

I also now realize that this PR that "wraps" isn't really wrapping it, at least not properly since it doesn't provide an Unwrap() error method. And adding such a method causes the tests to fail... So I'll just stick with what was in #776.

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Sounds good, but for consistency with the other error handlers the wrap was meant purely to wrap it in a connect error code. All the other wrap... functions call NewError so this should wrap in one too. It avoids other wrappers looking at it as each one checks if its already wrapped before processing. It has nothing to do with the Unwrap() error interface (I mean NewError does implement it but thats not the point). My comments were only to enforce the consistency of the current error handling.

}
return err
}

// wrapIfContextError applies CodeCanceled or CodeDeadlineExceeded to Go's
// context.Canceled and context.DeadlineExceeded errors, but only if they
// haven't already been wrapped.
Expand Down