package backend_test import ( "bytes" "crypto/rand" "crypto/sha256" "io" "io/ioutil" "testing" "github.com/restic/restic/backend" ) func TestHashAppendWriter(t *testing.T) { tests := []int{5, 23, 2<<18 + 23, 1 << 20} for _, size := range tests { data := make([]byte, size) _, err := io.ReadFull(rand.Reader, data) if err != nil { t.Fatalf("ReadFull: %v", err) } expectedHash := sha256.Sum256(data) target := bytes.NewBuffer(nil) wr := backend.NewHashAppendWriter(target, sha256.New()) _, err = wr.Write(data) ok(t, err) ok(t, wr.Close()) assert(t, len(target.Bytes()) == size+len(expectedHash), "HashAppendWriter: invalid number of bytes written: got %d, expected %d", len(target.Bytes()), size+len(expectedHash)) r := target.Bytes() resultingHash := r[len(r)-len(expectedHash):] assert(t, bytes.Equal(expectedHash[:], resultingHash), "HashAppendWriter: hashes do not match: expected %02x, got %02x", expectedHash, resultingHash) // write again, this must return an error _, err = wr.Write([]byte{23}) assert(t, err != nil, "HashAppendWriter: Write() after Close() did not return an error") } } func TestHashingWriter(t *testing.T) { tests := []int{5, 23, 2<<18 + 23, 1 << 20} for _, size := range tests { data := make([]byte, size) _, err := io.ReadFull(rand.Reader, data) if err != nil { t.Fatalf("ReadFull: %v", err) } expectedHash := sha256.Sum256(data) wr := backend.NewHashingWriter(ioutil.Discard, sha256.New()) n, err := io.Copy(wr, bytes.NewReader(data)) ok(t, err) assert(t, n == int64(size), "HashAppendWriter: invalid number of bytes written: got %d, expected %d", n, size) resultingHash := wr.Sum(nil) assert(t, bytes.Equal(expectedHash[:], resultingHash), "HashAppendWriter: hashes do not match: expected %02x, got %02x", expectedHash, resultingHash) } }