diff --git a/path/path.go b/path/path.go index dc2d5d1de..0891e8466 100644 --- a/path/path.go +++ b/path/path.go @@ -50,6 +50,24 @@ func (p Path) IsJustAKey() bool { return (len(parts) == 2 && parts[0] == "ipfs") } +// PopLastSegment returns a new Path without its final segment, and the final +// segment, separately. If there is no more to pop (the path is just a key), +// the original path is returned. +func (p Path) PopLastSegment() (Path, string, error) { + + if p.IsJustAKey() { + return p, "", nil + } + + segs := p.Segments() + newPath, err := ParsePath("/" + strings.Join(segs[:len(segs)-1], "/")) + if err != nil { + return "", "", err + } + + return newPath, segs[len(segs)-1], nil +} + func FromSegments(prefix string, seg ...string) (Path, error) { return ParsePath(prefix + strings.Join(seg, "/")) } diff --git a/path/path_test.go b/path/path_test.go index 33b93a3a0..a718bd81f 100644 --- a/path/path_test.go +++ b/path/path_test.go @@ -49,3 +49,31 @@ func TestIsJustAKey(t *testing.T) { } } } + +func TestPopLastSegment(t *testing.T) { + cases := map[string][]string{ + "QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n": []string{"/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n", ""}, + "/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n": []string{"/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n", ""}, + "/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n/a": []string{"/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n", "a"}, + "/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n/a/b": []string{"/ipfs/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n/a", "b"}, + "/ipns/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n/x/y/z": []string{"/ipns/QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n/x/y", "z"}, + } + + for p, expected := range cases { + path, err := ParsePath(p) + if err != nil { + t.Fatalf("ParsePath failed to parse \"%s\", but should have succeeded", p) + } + head, tail, err := path.PopLastSegment() + if err != nil { + t.Fatalf("PopLastSegment failed, but should have succeeded: %s", err) + } + headStr := head.String() + if headStr != expected[0] { + t.Fatalf("expected head of PopLastSegment(%s) to return %v, not %v", p, expected[0], headStr) + } + if tail != expected[1] { + t.Fatalf("expected tail of PopLastSegment(%s) to return %v, not %v", p, expected[1], tail) + } + } +}