1 files changed, 33 insertions, 0 deletions
diff --git a/object/fetch/peel_to_tree.go b/object/fetch/peel_to_tree.go
new file mode 100644
index 00000000..119e76ac
--- /dev/null
+++ b/object/fetch/peel_to_tree.go
@@ -0,0 +1,33 @@
+package fetch
+
+import (
+	"fmt"
+
+	"codeberg.org/lindenii/furgit/object/commit"
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	"codeberg.org/lindenii/furgit/object/stored"
+	"codeberg.org/lindenii/furgit/object/tag"
+	"codeberg.org/lindenii/furgit/object/tree"
+)
+
+// PeelToTree peels tags until it reaches a tree or commit. If it reaches a
+// commit, it returns the commit's root tree.
+func (r *Fetcher) PeelToTree(id objectid.ObjectID) (*stored.Stored[*tree.Tree], error) {
+	for {
+		obj, err := r.ExactObject(id)
+		if err != nil {
+			return nil, err
+		}
+
+		switch parsed := obj.Object().(type) {
+		case *tree.Tree:
+			return stored.New(id, parsed), nil
+		case *commit.Commit:
+			return r.ExactTree(parsed.Tree)
+		case *tag.Tag:
+			id = parsed.Target
+		default:
+			return nil, fmt.Errorf("object/fetch: expected tree-ish object %s, got %v", id, parsed.ObjectType())
+		}
+	}
+}