package writer_test import ( "bytes" "context" "encoding/hex" "io" "os" "testing" castorev1pb "code.tvl.fyi/tvix/castore/protos" "code.tvl.fyi/tvix/nar-bridge/pkg/reader" "code.tvl.fyi/tvix/nar-bridge/pkg/writer" storev1pb "code.tvl.fyi/tvix/store/protos" "github.com/stretchr/testify/require" "lukechampine.com/blake3" ) func mustDigest(d *castorev1pb.Directory) []byte { dgst, err := d.Digest() if err != nil { panic(err) } return dgst } func TestSymlink(t *testing.T) { pathInfo := &storev1pb.PathInfo{ Node: &castorev1pb.Node{ Node: &castorev1pb.Node_Symlink{ Symlink: &castorev1pb.SymlinkNode{ Name: []byte("doesntmatter"), Target: []byte("/nix/store/somewhereelse"), }, }, }, } var buf bytes.Buffer err := writer.Export(&buf, pathInfo, func([]byte) (*castorev1pb.Directory, error) { panic("no directories expected") }, func([]byte) (io.ReadCloser, error) { panic("no files expected") }) require.NoError(t, err, "exporter shouldn't fail") f, err := os.Open("../../testdata/symlink.nar") require.NoError(t, err) bytesExpected, err := io.ReadAll(f) if err != nil { panic(err) } require.Equal(t, bytesExpected, buf.Bytes(), "expected nar contents to match") } func TestRegular(t *testing.T) { // The blake3 digest of the 0x01 byte. BLAKE3_DIGEST_0X01 := []byte{ 0x48, 0xfc, 0x72, 0x1f, 0xbb, 0xc1, 0x72, 0xe0, 0x92, 0x5f, 0xa2, 0x7a, 0xf1, 0x67, 0x1d, 0xe2, 0x25, 0xba, 0x92, 0x71, 0x34, 0x80, 0x29, 0x98, 0xb1, 0x0a, 0x15, 0x68, 0xa1, 0x88, 0x65, 0x2b, } pathInfo := &storev1pb.PathInfo{ Node: &castorev1pb.Node{ Node: &castorev1pb.Node_File{ File: &castorev1pb.FileNode{ Name: []byte("doesntmatter"), Digest: BLAKE3_DIGEST_0X01, Size: 1, Executable: false, }, }, }, } var buf bytes.Buffer err := writer.Export(&buf, pathInfo, func([]byte) (*castorev1pb.Directory, error) { panic("no directories expected") }, func(blobRef []byte) (io.ReadCloser, error) { if !bytes.Equal(blobRef, BLAKE3_DIGEST_0X01) { panic("unexpected blobref") } return io.NopCloser(bytes.NewBuffer([]byte{0x01})), nil }) require.NoError(t, err, "exporter shouldn't fail") f, err := os.Open("../../testdata/onebyteregular.nar") require.NoError(t, err) bytesExpected, err := io.ReadAll(f) if err != nil { panic(err) } require.Equal(t, bytesExpected, buf.Bytes(), "expected nar contents to match") } func TestEmptyDirectory(t *testing.T) { // construct empty directory node this refers to emptyDirectory := &castorev1pb.Directory{ Directories: []*castorev1pb.DirectoryNode{}, Files: []*castorev1pb.FileNode{}, Symlinks: []*castorev1pb.SymlinkNode{}, } emptyDirectoryDigest := mustDigest(emptyDirectory) pathInfo := &storev1pb.PathInfo{ Node: &castorev1pb.Node{ Node: &castorev1pb.Node_Directory{ Directory: &castorev1pb.DirectoryNode{ Name: []byte("doesntmatter"), Digest: emptyDirectoryDigest, Size: 0, }, }, }, } var buf bytes.Buffer err := writer.Export(&buf, pathInfo, func(directoryRef []byte) (*castorev1pb.Directory, error) { if !bytes.Equal(directoryRef, emptyDirectoryDigest) { panic("unexpected directoryRef") } return emptyDirectory, nil }, func([]byte) (io.ReadCloser, error) { panic("no files expected") }) require.NoError(t, err, "exporter shouldn't fail") f, err := os.Open("../../testdata/emptydirectory.nar") require.NoError(t, err) bytesExpected, err := io.ReadAll(f) if err != nil { panic(err) } require.Equal(t, bytesExpected, buf.Bytes(), "expected nar contents to match") } func TestFull(t *testing.T) { // We pipe nar_1094wph9z4nwlgvsd53abfz8i117ykiv5dwnq9nnhz846s7xqd7d.nar to the exporter, // and store all the file contents and directory objects received in two hashmaps. // We then feed it to the writer, and test we come up with the same NAR file. f, err := os.Open("../../testdata/nar_1094wph9z4nwlgvsd53abfz8i117ykiv5dwnq9nnhz846s7xqd7d.nar") require.NoError(t, err) narContents, err := io.ReadAll(f) require.NoError(t, err) filesMap := make(map[string][]byte, 0) directoriesMap := make(map[string]*castorev1pb.Directory) r := reader.New(bytes.NewBuffer(narContents)) pathInfo, err := r.Import( context.Background(), func(fileReader io.Reader) error { fileContents, err := io.ReadAll(fileReader) require.NoError(t, err) b3Writer := blake3.New(32, nil) _, err = io.Copy(b3Writer, bytes.NewReader(fileContents)) require.NoError(t, err) // put it in filesMap filesMap[hex.EncodeToString(b3Writer.Sum(nil))] = fileContents return nil }, func(directory *castorev1pb.Directory) error { dgst := mustDigest(directory) directoriesMap[hex.EncodeToString(dgst)] = directory return nil }, ) require.NoError(t, err) // done populating everything, now actually test the export :-) var buf bytes.Buffer err = writer.Export( &buf, pathInfo, func(directoryRef []byte) (*castorev1pb.Directory, error) { d, found := directoriesMap[hex.EncodeToString(directoryRef)] if !found { panic("directories not found") } return d, nil }, func(fileRef []byte) (io.ReadCloser, error) { fileContents, found := filesMap[hex.EncodeToString(fileRef)] if !found { panic("file not found") } return io.NopCloser(bytes.NewReader(fileContents)), nil }, ) require.NoError(t, err, "exporter shouldn't fail") require.Equal(t, narContents, buf.Bytes()) }