internal/testgit: packobjects, verifypack

1 files changed, 47 insertions, 0 deletions

diff --git a/internal/testgit/packobjects.go b/internal/testgit/packobjects.go
new file mode 100644
index 00000000..9f56eef0
--- /dev/null
+++ b/internal/testgit/packobjects.go
@@ -0,0 +1,47 @@
+package testgit
+
+import (
+	"bytes"
+	"iter"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"lindenii.org/go/furgit/object/id"
+)
+
+// PackObjectsOptions controls one pack-objects invocation.
+type PackObjectsOptions struct {
+	// RevIndex requests writing a .rev reverse index alongside the pack.
+	RevIndex bool
+}
+
+// PackObjects packs the supplied objects with git pack-objects
+// into a temporary directory,
+// and returns the artifact path prefix "<dir>/pack-<hash>",
+// to which ".pack", ".idx", and ".rev" suffixes apply.
+func (repo *Repo) PackObjects(tb testing.TB, oids iter.Seq[id.ObjectID], opts PackObjectsOptions) (string, error) {
+	tb.Helper()
+
+	dir := tb.TempDir()
+
+	var stdin bytes.Buffer
+	for oid := range oids {
+		stdin.WriteString(oid.String())
+		stdin.WriteByte('\n')
+	}
+
+	revIndex := "false"
+	if opts.RevIndex {
+		revIndex = "true"
+	}
+
+	out, err := repo.run(tb, &stdin,
+		"git", "-c", "pack.writeReverseIndex="+revIndex,
+		"pack-objects", "--end-of-options", filepath.Join(dir, "pack"))
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(dir, "pack-"+strings.TrimSpace(string(out))), nil
+}