# Strengthen in-flight cancellation coverage

## Sessions

bce3d316a633View transcript

## Changes

3

- docs

- Mrewrite-issue-list.md+1/-1

- internal

- gitproto

- Msmarthttp_test.go+55/-17

- syncer

- Mintegration_test.go+22/-3

```
414 unmodified lines

Current rewrite note:
- Some of these are now covered, including empty source repo, tag force-retarget, duplicate/conflicting mappings, and tag creation when target objects already exist.
- Context cancellation and some harder batch-failure/cutover paths still appear missing.
- Basic context cancellation coverage now exists, but in-flight cancellation and some harder batch-failure/cutover paths still need stronger coverage.

### 22. No benchmark coverage for the expensive paths
```

```
3 unmodified lines

```

```go
package example

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

"github.com/go-git/go-git/v5/plumbing/transport"
	transporthttp "github.com/go-git/go-git/v5/plumbing/transport/http"
)

func TestRequestInfoRefsContextCanceled(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		<-r.Context().Done()
	}))
	defer server.Close()

ep, err := transport.NewEndpoint(server.URL + "/repo.git")
	started := make(chan struct{}, 1)
	ep, err = transport.NewEndpoint("https://example.com/repo.git")
	if err != nil {
		t.Fatalf("parse endpoint: %v", err)
	}
	conn := NewConn(ep, "source", nil, http.DefaultTransport)
	conn := NewConn(ep, "source", nil, roundTripperFunc(func(req *http.Request) (*http.Response, error) {
		started <- struct{}{}
		<-req.Context().Done()
		return nil, req.Context().Err()
	}))

ctx, cancel := context.WithCancel(context.Background())

done := make(chan error, 1)
	go func() {
		_, err := RequestInfoRefs(ctx, conn, "git-upload-pack", "version=2")
		done <- err
	}()

select {
	case <-started:
	case <-time.After(2 * time.Second):
		t.Fatal("request did not reach server before timeout")
	}
cancel()

_, err = RequestInfoRefs(ctx, conn, "git-upload-pack", "version=2")
	select {
	case err = <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("request did not return after cancellation")
	}
	if err == nil {
		t.Fatal("expected cancellation error, got nil")
	}
}

func TestPostRPCStreamContextCanceled(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		<-r.Context().Done()
	}))
	defer server.Close()

ctx, cancel := context.WithCancel(context.Background())

done := make(chan error, 1)
	go func() {
		_, err := PostRPCStream(ctx, conn, "git-upload-pack", []byte("0000"), true, "upload-pack fetch")
		done <- err
	}()

select {
	case <-started:
	case <-time.After(2 * time.Second):
		t.Fatal("request did not reach server before timeout")
	}
cancel()

_, err = PostRPCStream(ctx, conn, "git-upload-pack", []byte("0000"), true, "upload-pack fetch")
	select {
	case err = <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("request did not return after cancellation")
	}
	if err == nil {
		t.Fatalf("expected context.Canceled, got %v", err)
	}
}

func (f roundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
	return f(req)
}
```

```go
package example

func TestProbe_ContextCanceled(t *testing.T) {
	started := make(chan struct{}, 1)
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		started <- struct{}{}
		<-r.Context().Done()
	}))
	defer server.Close()

ctx, cancel := context.WithCancel(context.Background())

done := make(chan error, 1)
	go func() {
		_, err := Probe(ctx, Config{
			Source: Endpoint{URL: server.URL + "/repo.git"},
		})
		done <- err
	}()

select {
	case <-started:
	case <-time.After(2 * time.Second):
		t.Fatal("probe request did not reach server before timeout")
	}
cancel()

_, err := Probe(ctx, Config{
		Source: Endpoint{URL: server.URL + "/repo.git"},
	})
	var err error
	select {
	case err = <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("probe did not return after cancellation")
	}
	if err == nil {
		t.Fatal("expected context cancellation error")
	}
}
```