// TestChecksumAddToHeader tests that adding and retrieving a checksum on a header works
func TestChecksumAddToHeader(t *testing.T) {
	tests := []struct {
		name     string
		checksum ChecksumType
		fullobj  bool
		wantErr  bool
	}{
		{"CRC32-composite", ChecksumCRC32, false, false},
		{"CRC32-full-object", ChecksumCRC32, true, false},
		{"CRC32C-composite", ChecksumCRC32C, false, false},
		{"CRC32C-full-object", ChecksumCRC32C, true, false},

		rn, err := r.ReadAt(b, tt.off)
		got := string(b[:rn])
		if got != tt.want {
			t.Errorf("%d. got %q; want %q", i, got, tt.want)
		}
		if fmt.Sprintf("%v", err) != fmt.Sprintf("%v", tt.wanterr) {
			t.Errorf("%d. got error = %v; want %v", i, err, tt.wanterr)
		}
	}
}

func TestReaderAtConcurrent(t *testing.T) {
	// Test for the race detector, to verify ReadAt doesn't mutate
	// any state.
	r := NewReader([]byte("0123456789"))

			br := NewReaderSize(r, size)
			want := func(s string, wantErr error) {
				p := make([]byte, 50)
				n, err := br.Read(p)
				if err != wantErr || n != len(s) || string(p[:n]) != s {
					t.Fatalf("read(%d) = %q, %v, want %q, %v", len(p), string(p[:n]), err, s, wantErr)
				}
				t.Logf("read(%d) = %q, %v", len(p), string(p[:n]), err)
			}
			want("abc", nil)

func TestHeaderTooLongErr(t *testing.T) {
	var headerTests = []struct {
		name    string
		extra   []byte
		wanterr error
	}{
		{
			name:    strings.Repeat("x", 1<<16),
			extra:   []byte{},
			wanterr: errLongName,
		},
		{
			name:    "long_extra",
			extra:   bytes.Repeat([]byte{0xff}, 1<<16),
			wanterr: errLongExtra,
		},
	}

	// write a zip file
	buf := new(bytes.Buffer)
	w := NewWriter(buf)

			if err != nil {
				if !testCase.wantErr {
					t.Fatal(err)
				}
				t.Logf("got expected error: %v", err)
				return
			}

			if err = s3Select.Open(newBytesRSC(testCase.input)); err != nil {
				if !testCase.wantErr {
					t.Fatal(err)
				}
				t.Logf("got expected error: %v", err)
				return
			} else if testCase.wantErr {
				t.Error("did not get expected error")

				if err != nil {
					if !test.wantErr {
						t.Errorf("%s: %v", path, err)
					}
					sawErr = true
					return nil
				}
				files = append(files, path)
				return nil
			})
			if err != nil {
				t.Errorf("fs.WalkDir error: %v", err)
			}
			if test.wantErr && !sawErr {
				t.Error("succeeded but want error")
			} else if !test.wantErr && sawErr {
				t.Error("unexpected error")

			}
			var apiErr APIErrorResponse
			err = xml.Unmarshal(b, &apiErr)
			if err != nil {
				t.Fatal(err)
			}
			gotErr := apiErr.Code
			wantErr := testCase.wantAPICode
			if gotErr != wantErr {
				t.Errorf("test %d: want api error %q, got %q", i, wantErr, gotErr)
			}
			if testCase.wantHeaders != nil {
				for k, v := range testCase.wantHeaders {
					got := rec.Header().Get(k)
					if got != v {