github.com/rumpl/bof@v23.0.0-rc.2+incompatible/pkg/archive/changes_test.go (about)

     1  package archive // import "github.com/docker/docker/pkg/archive"
     2  
     3  import (
     4  	"os"
     5  	"os/exec"
     6  	"path"
     7  	"path/filepath"
     8  	"runtime"
     9  	"sort"
    10  	"strconv"
    11  	"strings"
    12  	"syscall"
    13  	"testing"
    14  	"time"
    15  
    16  	"github.com/Microsoft/hcsshim/osversion"
    17  	"github.com/docker/docker/pkg/idtools"
    18  	"github.com/docker/docker/pkg/parsers/kernel"
    19  	"github.com/docker/docker/pkg/system"
    20  	"gotest.tools/v3/assert"
    21  	"gotest.tools/v3/skip"
    22  )
    23  
    24  func max(x, y int) int {
    25  	if x >= y {
    26  		return x
    27  	}
    28  	return y
    29  }
    30  
    31  func copyDir(src, dst string) error {
    32  	if runtime.GOOS != "windows" {
    33  		return exec.Command("cp", "-a", src, dst).Run()
    34  	}
    35  
    36  	// Could have used xcopy src dst /E /I /H /Y /B. However, xcopy has the
    37  	// unfortunate side effect of not preserving timestamps of newly created
    38  	// directories in the target directory, so we don't get accurate changes.
    39  	// Use robocopy instead. Note this isn't available in microsoft/nanoserver.
    40  	// But it has gotchas. See https://weblogs.sqlteam.com/robv/archive/2010/02/17/61106.aspx
    41  	err := exec.Command("robocopy", filepath.FromSlash(src), filepath.FromSlash(dst), "/SL", "/COPYALL", "/MIR").Run()
    42  	if exiterr, ok := err.(*exec.ExitError); ok {
    43  		if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
    44  			if status.ExitStatus()&24 == 0 {
    45  				return nil
    46  			}
    47  		}
    48  	}
    49  	return err
    50  }
    51  
    52  type FileType uint32
    53  
    54  const (
    55  	Regular FileType = iota
    56  	Dir
    57  	Symlink
    58  )
    59  
    60  type FileData struct {
    61  	filetype    FileType
    62  	path        string
    63  	contents    string
    64  	permissions os.FileMode
    65  }
    66  
    67  func createSampleDir(t *testing.T, root string) {
    68  	files := []FileData{
    69  		{filetype: Regular, path: "file1", contents: "file1\n", permissions: 0600},
    70  		{filetype: Regular, path: "file2", contents: "file2\n", permissions: 0666},
    71  		{filetype: Regular, path: "file3", contents: "file3\n", permissions: 0404},
    72  		{filetype: Regular, path: "file4", contents: "file4\n", permissions: 0600},
    73  		{filetype: Regular, path: "file5", contents: "file5\n", permissions: 0600},
    74  		{filetype: Regular, path: "file6", contents: "file6\n", permissions: 0600},
    75  		{filetype: Regular, path: "file7", contents: "file7\n", permissions: 0600},
    76  		{filetype: Dir, path: "dir1", contents: "", permissions: 0740},
    77  		{filetype: Regular, path: "dir1/file1-1", contents: "file1-1\n", permissions: 01444},
    78  		{filetype: Regular, path: "dir1/file1-2", contents: "file1-2\n", permissions: 0666},
    79  		{filetype: Dir, path: "dir2", contents: "", permissions: 0700},
    80  		{filetype: Regular, path: "dir2/file2-1", contents: "file2-1\n", permissions: 0666},
    81  		{filetype: Regular, path: "dir2/file2-2", contents: "file2-2\n", permissions: 0666},
    82  		{filetype: Dir, path: "dir3", contents: "", permissions: 0700},
    83  		{filetype: Regular, path: "dir3/file3-1", contents: "file3-1\n", permissions: 0666},
    84  		{filetype: Regular, path: "dir3/file3-2", contents: "file3-2\n", permissions: 0666},
    85  		{filetype: Dir, path: "dir4", contents: "", permissions: 0700},
    86  		{filetype: Regular, path: "dir4/file3-1", contents: "file4-1\n", permissions: 0666},
    87  		{filetype: Regular, path: "dir4/file3-2", contents: "file4-2\n", permissions: 0666},
    88  		{filetype: Symlink, path: "symlink1", contents: "target1", permissions: 0666},
    89  		{filetype: Symlink, path: "symlink2", contents: "target2", permissions: 0666},
    90  		{filetype: Symlink, path: "symlink3", contents: root + "/file1", permissions: 0666},
    91  		{filetype: Symlink, path: "symlink4", contents: root + "/symlink3", permissions: 0666},
    92  		{filetype: Symlink, path: "dirSymlink", contents: root + "/dir1", permissions: 0740},
    93  	}
    94  	provisionSampleDir(t, root, files)
    95  }
    96  
    97  func provisionSampleDir(t *testing.T, root string, files []FileData) {
    98  	now := time.Now()
    99  	for _, info := range files {
   100  		p := path.Join(root, info.path)
   101  		if info.filetype == Dir {
   102  			err := os.MkdirAll(p, info.permissions)
   103  			assert.NilError(t, err)
   104  		} else if info.filetype == Regular {
   105  			err := os.WriteFile(p, []byte(info.contents), info.permissions)
   106  			assert.NilError(t, err)
   107  		} else if info.filetype == Symlink {
   108  			err := os.Symlink(info.contents, p)
   109  			assert.NilError(t, err)
   110  		}
   111  
   112  		if info.filetype != Symlink {
   113  			// Set a consistent ctime, atime for all files and dirs
   114  			err := system.Chtimes(p, now, now)
   115  			assert.NilError(t, err)
   116  		}
   117  	}
   118  }
   119  
   120  func TestChangeString(t *testing.T) {
   121  	modifyChange := Change{"change", ChangeModify}
   122  	toString := modifyChange.String()
   123  	if toString != "C change" {
   124  		t.Fatalf("String() of a change with ChangeModify Kind should have been %s but was %s", "C change", toString)
   125  	}
   126  	addChange := Change{"change", ChangeAdd}
   127  	toString = addChange.String()
   128  	if toString != "A change" {
   129  		t.Fatalf("String() of a change with ChangeAdd Kind should have been %s but was %s", "A change", toString)
   130  	}
   131  	deleteChange := Change{"change", ChangeDelete}
   132  	toString = deleteChange.String()
   133  	if toString != "D change" {
   134  		t.Fatalf("String() of a change with ChangeDelete Kind should have been %s but was %s", "D change", toString)
   135  	}
   136  }
   137  
   138  func TestChangesWithNoChanges(t *testing.T) {
   139  	rwLayer, err := os.MkdirTemp("", "docker-changes-test")
   140  	assert.NilError(t, err)
   141  	defer os.RemoveAll(rwLayer)
   142  	layer, err := os.MkdirTemp("", "docker-changes-test-layer")
   143  	assert.NilError(t, err)
   144  	defer os.RemoveAll(layer)
   145  	createSampleDir(t, layer)
   146  	changes, err := Changes([]string{layer}, rwLayer)
   147  	assert.NilError(t, err)
   148  	if len(changes) != 0 {
   149  		t.Fatalf("Changes with no difference should have detect no changes, but detected %d", len(changes))
   150  	}
   151  }
   152  
   153  func TestChangesWithChanges(t *testing.T) {
   154  	// Mock the readonly layer
   155  	layer, err := os.MkdirTemp("", "docker-changes-test-layer")
   156  	assert.NilError(t, err)
   157  	defer os.RemoveAll(layer)
   158  	createSampleDir(t, layer)
   159  	os.MkdirAll(path.Join(layer, "dir1/subfolder"), 0740)
   160  
   161  	// Mock the RW layer
   162  	rwLayer, err := os.MkdirTemp("", "docker-changes-test")
   163  	assert.NilError(t, err)
   164  	defer os.RemoveAll(rwLayer)
   165  
   166  	// Create a folder in RW layer
   167  	dir1 := path.Join(rwLayer, "dir1")
   168  	os.MkdirAll(dir1, 0740)
   169  	deletedFile := path.Join(dir1, ".wh.file1-2")
   170  	os.WriteFile(deletedFile, []byte{}, 0600)
   171  	modifiedFile := path.Join(dir1, "file1-1")
   172  	os.WriteFile(modifiedFile, []byte{0x00}, 01444)
   173  	// Let's add a subfolder for a newFile
   174  	subfolder := path.Join(dir1, "subfolder")
   175  	os.MkdirAll(subfolder, 0740)
   176  	newFile := path.Join(subfolder, "newFile")
   177  	os.WriteFile(newFile, []byte{}, 0740)
   178  
   179  	changes, err := Changes([]string{layer}, rwLayer)
   180  	assert.NilError(t, err)
   181  
   182  	expectedChanges := []Change{
   183  		{filepath.FromSlash("/dir1"), ChangeModify},
   184  		{filepath.FromSlash("/dir1/file1-1"), ChangeModify},
   185  		{filepath.FromSlash("/dir1/file1-2"), ChangeDelete},
   186  		{filepath.FromSlash("/dir1/subfolder"), ChangeModify},
   187  		{filepath.FromSlash("/dir1/subfolder/newFile"), ChangeAdd},
   188  	}
   189  	checkChanges(expectedChanges, changes, t)
   190  }
   191  
   192  // See https://github.com/docker/docker/pull/13590
   193  func TestChangesWithChangesGH13590(t *testing.T) {
   194  	// TODO Windows. Needs further investigation to identify the failure
   195  	if runtime.GOOS == "windows" {
   196  		t.Skip("needs more investigation")
   197  	}
   198  	baseLayer, err := os.MkdirTemp("", "docker-changes-test.")
   199  	assert.NilError(t, err)
   200  	defer os.RemoveAll(baseLayer)
   201  
   202  	dir3 := path.Join(baseLayer, "dir1/dir2/dir3")
   203  	os.MkdirAll(dir3, 07400)
   204  
   205  	file := path.Join(dir3, "file.txt")
   206  	os.WriteFile(file, []byte("hello"), 0666)
   207  
   208  	layer, err := os.MkdirTemp("", "docker-changes-test2.")
   209  	assert.NilError(t, err)
   210  	defer os.RemoveAll(layer)
   211  
   212  	// Test creating a new file
   213  	if err := copyDir(baseLayer+"/dir1", layer+"/"); err != nil {
   214  		t.Fatalf("Cmd failed: %q", err)
   215  	}
   216  
   217  	os.Remove(path.Join(layer, "dir1/dir2/dir3/file.txt"))
   218  	file = path.Join(layer, "dir1/dir2/dir3/file1.txt")
   219  	os.WriteFile(file, []byte("bye"), 0666)
   220  
   221  	changes, err := Changes([]string{baseLayer}, layer)
   222  	assert.NilError(t, err)
   223  
   224  	expectedChanges := []Change{
   225  		{"/dir1/dir2/dir3", ChangeModify},
   226  		{"/dir1/dir2/dir3/file1.txt", ChangeAdd},
   227  	}
   228  	checkChanges(expectedChanges, changes, t)
   229  
   230  	// Now test changing a file
   231  	layer, err = os.MkdirTemp("", "docker-changes-test3.")
   232  	assert.NilError(t, err)
   233  	defer os.RemoveAll(layer)
   234  
   235  	if err := copyDir(baseLayer+"/dir1", layer+"/"); err != nil {
   236  		t.Fatalf("Cmd failed: %q", err)
   237  	}
   238  
   239  	file = path.Join(layer, "dir1/dir2/dir3/file.txt")
   240  	os.WriteFile(file, []byte("bye"), 0666)
   241  
   242  	changes, err = Changes([]string{baseLayer}, layer)
   243  	assert.NilError(t, err)
   244  
   245  	expectedChanges = []Change{
   246  		{"/dir1/dir2/dir3/file.txt", ChangeModify},
   247  	}
   248  	checkChanges(expectedChanges, changes, t)
   249  }
   250  
   251  // Create a directory, copy it, make sure we report no changes between the two
   252  func TestChangesDirsEmpty(t *testing.T) {
   253  	// Note we parse kernel.GetKernelVersion rather than system.GetOSVersion
   254  	// as test binaries aren't manifested, so would otherwise report the wrong
   255  	// build number.
   256  	if runtime.GOOS == "windows" {
   257  		v, err := kernel.GetKernelVersion()
   258  		assert.NilError(t, err)
   259  		build, _ := strconv.Atoi(strings.Split(strings.SplitN(v.String(), " ", 3)[2][1:], ".")[0])
   260  		if build >= osversion.V19H1 {
   261  			t.Skip("FIXME: broken on Windows 1903 and up; see #39846")
   262  		}
   263  	}
   264  
   265  	src, err := os.MkdirTemp("", "docker-changes-test")
   266  	assert.NilError(t, err)
   267  	defer os.RemoveAll(src)
   268  	createSampleDir(t, src)
   269  	dst := src + "-copy"
   270  	err = copyDir(src, dst)
   271  	assert.NilError(t, err)
   272  	defer os.RemoveAll(dst)
   273  	changes, err := ChangesDirs(dst, src)
   274  	assert.NilError(t, err)
   275  
   276  	if len(changes) != 0 {
   277  		t.Fatalf("Reported changes for identical dirs: %v", changes)
   278  	}
   279  	os.RemoveAll(src)
   280  	os.RemoveAll(dst)
   281  }
   282  
   283  func mutateSampleDir(t *testing.T, root string) {
   284  	// Remove a regular file
   285  	err := os.RemoveAll(path.Join(root, "file1"))
   286  	assert.NilError(t, err)
   287  
   288  	// Remove a directory
   289  	err = os.RemoveAll(path.Join(root, "dir1"))
   290  	assert.NilError(t, err)
   291  
   292  	// Remove a symlink
   293  	err = os.RemoveAll(path.Join(root, "symlink1"))
   294  	assert.NilError(t, err)
   295  
   296  	// Rewrite a file
   297  	err = os.WriteFile(path.Join(root, "file2"), []byte("fileNN\n"), 0777)
   298  	assert.NilError(t, err)
   299  
   300  	// Replace a file
   301  	err = os.RemoveAll(path.Join(root, "file3"))
   302  	assert.NilError(t, err)
   303  	err = os.WriteFile(path.Join(root, "file3"), []byte("fileMM\n"), 0404)
   304  	assert.NilError(t, err)
   305  
   306  	// Touch file
   307  	err = system.Chtimes(path.Join(root, "file4"), time.Now().Add(time.Second), time.Now().Add(time.Second))
   308  	assert.NilError(t, err)
   309  
   310  	// Replace file with dir
   311  	err = os.RemoveAll(path.Join(root, "file5"))
   312  	assert.NilError(t, err)
   313  	err = os.MkdirAll(path.Join(root, "file5"), 0666)
   314  	assert.NilError(t, err)
   315  
   316  	// Create new file
   317  	err = os.WriteFile(path.Join(root, "filenew"), []byte("filenew\n"), 0777)
   318  	assert.NilError(t, err)
   319  
   320  	// Create new dir
   321  	err = os.MkdirAll(path.Join(root, "dirnew"), 0766)
   322  	assert.NilError(t, err)
   323  
   324  	// Create a new symlink
   325  	err = os.Symlink("targetnew", path.Join(root, "symlinknew"))
   326  	assert.NilError(t, err)
   327  
   328  	// Change a symlink
   329  	err = os.RemoveAll(path.Join(root, "symlink2"))
   330  	assert.NilError(t, err)
   331  
   332  	err = os.Symlink("target2change", path.Join(root, "symlink2"))
   333  	assert.NilError(t, err)
   334  
   335  	// Replace dir with file
   336  	err = os.RemoveAll(path.Join(root, "dir2"))
   337  	assert.NilError(t, err)
   338  	err = os.WriteFile(path.Join(root, "dir2"), []byte("dir2\n"), 0777)
   339  	assert.NilError(t, err)
   340  
   341  	// Touch dir
   342  	err = system.Chtimes(path.Join(root, "dir3"), time.Now().Add(time.Second), time.Now().Add(time.Second))
   343  	assert.NilError(t, err)
   344  }
   345  
   346  func TestChangesDirsMutated(t *testing.T) {
   347  	// Note we parse kernel.GetKernelVersion rather than system.GetOSVersion
   348  	// as test binaries aren't manifested, so would otherwise report the wrong
   349  	// build number.
   350  	if runtime.GOOS == "windows" {
   351  		v, err := kernel.GetKernelVersion()
   352  		assert.NilError(t, err)
   353  		build, _ := strconv.Atoi(strings.Split(strings.SplitN(v.String(), " ", 3)[2][1:], ".")[0])
   354  		if build >= osversion.V19H1 {
   355  			t.Skip("FIXME: broken on Windows 1903 and up; see #39846")
   356  		}
   357  	}
   358  
   359  	src, err := os.MkdirTemp("", "docker-changes-test")
   360  	assert.NilError(t, err)
   361  	createSampleDir(t, src)
   362  	dst := src + "-copy"
   363  	err = copyDir(src, dst)
   364  	assert.NilError(t, err)
   365  	defer os.RemoveAll(src)
   366  	defer os.RemoveAll(dst)
   367  
   368  	mutateSampleDir(t, dst)
   369  
   370  	changes, err := ChangesDirs(dst, src)
   371  	assert.NilError(t, err)
   372  
   373  	sort.Sort(changesByPath(changes))
   374  
   375  	expectedChanges := []Change{
   376  		{filepath.FromSlash("/dir1"), ChangeDelete},
   377  		{filepath.FromSlash("/dir2"), ChangeModify},
   378  	}
   379  
   380  	// Note there is slight difference between the Linux and Windows
   381  	// implementations here. Due to https://github.com/moby/moby/issues/9874,
   382  	// and the fix at https://github.com/moby/moby/pull/11422, Linux does not
   383  	// consider a change to the directory time as a change. Windows on NTFS
   384  	// does. See https://github.com/moby/moby/pull/37982 for more information.
   385  	//
   386  	// Note also: https://github.com/moby/moby/pull/37982#discussion_r223523114
   387  	// that differences are ordered in the way the test is currently written, hence
   388  	// this is in the middle of the list of changes rather than at the start or
   389  	// end. Potentially can be addressed later.
   390  	if runtime.GOOS == "windows" {
   391  		expectedChanges = append(expectedChanges, Change{filepath.FromSlash("/dir3"), ChangeModify})
   392  	}
   393  
   394  	expectedChanges = append(expectedChanges, []Change{
   395  		{filepath.FromSlash("/dirnew"), ChangeAdd},
   396  		{filepath.FromSlash("/file1"), ChangeDelete},
   397  		{filepath.FromSlash("/file2"), ChangeModify},
   398  		{filepath.FromSlash("/file3"), ChangeModify},
   399  		{filepath.FromSlash("/file4"), ChangeModify},
   400  		{filepath.FromSlash("/file5"), ChangeModify},
   401  		{filepath.FromSlash("/filenew"), ChangeAdd},
   402  		{filepath.FromSlash("/symlink1"), ChangeDelete},
   403  		{filepath.FromSlash("/symlink2"), ChangeModify},
   404  		{filepath.FromSlash("/symlinknew"), ChangeAdd},
   405  	}...)
   406  
   407  	for i := 0; i < max(len(changes), len(expectedChanges)); i++ {
   408  		if i >= len(expectedChanges) {
   409  			t.Fatalf("unexpected change %s\n", changes[i].String())
   410  		}
   411  		if i >= len(changes) {
   412  			t.Fatalf("no change for expected change %s\n", expectedChanges[i].String())
   413  		}
   414  		if changes[i].Path == expectedChanges[i].Path {
   415  			if changes[i] != expectedChanges[i] {
   416  				t.Fatalf("Wrong change for %s, expected %s, got %s\n", changes[i].Path, changes[i].String(), expectedChanges[i].String())
   417  			}
   418  		} else if changes[i].Path < expectedChanges[i].Path {
   419  			t.Fatalf("unexpected change %q %q\n", changes[i].String(), expectedChanges[i].Path)
   420  		} else {
   421  			t.Fatalf("no change for expected change %s != %s\n", expectedChanges[i].String(), changes[i].String())
   422  		}
   423  	}
   424  }
   425  
   426  func TestApplyLayer(t *testing.T) {
   427  	// TODO Windows. This is very close to working, but it fails with changes
   428  	// to \symlinknew and \symlink2. The destination has an updated
   429  	// Access/Modify/Change/Birth date to the source (~3/100th sec different).
   430  	// Needs further investigation as to why, but I currently believe this is
   431  	// just the way NTFS works. I don't think it's a bug in this test or archive.
   432  	if runtime.GOOS == "windows" {
   433  		t.Skip("needs further investigation")
   434  	}
   435  	src, err := os.MkdirTemp("", "docker-changes-test")
   436  	assert.NilError(t, err)
   437  	createSampleDir(t, src)
   438  	defer os.RemoveAll(src)
   439  	dst := src + "-copy"
   440  	err = copyDir(src, dst)
   441  	assert.NilError(t, err)
   442  	mutateSampleDir(t, dst)
   443  	defer os.RemoveAll(dst)
   444  
   445  	changes, err := ChangesDirs(dst, src)
   446  	assert.NilError(t, err)
   447  
   448  	layer, err := ExportChanges(dst, changes, idtools.IdentityMapping{})
   449  	assert.NilError(t, err)
   450  
   451  	layerCopy, err := NewTempArchive(layer, "")
   452  	assert.NilError(t, err)
   453  
   454  	_, err = ApplyLayer(src, layerCopy)
   455  	assert.NilError(t, err)
   456  
   457  	changes2, err := ChangesDirs(src, dst)
   458  	assert.NilError(t, err)
   459  
   460  	if len(changes2) != 0 {
   461  		t.Fatalf("Unexpected differences after reapplying mutation: %v", changes2)
   462  	}
   463  }
   464  
   465  func TestChangesSizeWithHardlinks(t *testing.T) {
   466  	// TODO Windows. Needs further investigation. Likely in ChangeSizes not
   467  	// coping correctly with hardlinks on Windows.
   468  	if runtime.GOOS == "windows" {
   469  		t.Skip("needs further investigation")
   470  	}
   471  	srcDir, err := os.MkdirTemp("", "docker-test-srcDir")
   472  	assert.NilError(t, err)
   473  	defer os.RemoveAll(srcDir)
   474  
   475  	destDir, err := os.MkdirTemp("", "docker-test-destDir")
   476  	assert.NilError(t, err)
   477  	defer os.RemoveAll(destDir)
   478  
   479  	creationSize, err := prepareUntarSourceDirectory(100, destDir, true)
   480  	assert.NilError(t, err)
   481  
   482  	changes, err := ChangesDirs(destDir, srcDir)
   483  	assert.NilError(t, err)
   484  
   485  	got := ChangesSize(destDir, changes)
   486  	if got != int64(creationSize) {
   487  		t.Errorf("Expected %d bytes of changes, got %d", creationSize, got)
   488  	}
   489  }
   490  
   491  func TestChangesSizeWithNoChanges(t *testing.T) {
   492  	size := ChangesSize("/tmp", nil)
   493  	if size != 0 {
   494  		t.Fatalf("ChangesSizes with no changes should be 0, was %d", size)
   495  	}
   496  }
   497  
   498  func TestChangesSizeWithOnlyDeleteChanges(t *testing.T) {
   499  	changes := []Change{
   500  		{Path: "deletedPath", Kind: ChangeDelete},
   501  	}
   502  	size := ChangesSize("/tmp", changes)
   503  	if size != 0 {
   504  		t.Fatalf("ChangesSizes with only delete changes should be 0, was %d", size)
   505  	}
   506  }
   507  
   508  func TestChangesSize(t *testing.T) {
   509  	parentPath, err := os.MkdirTemp("", "docker-changes-test")
   510  	assert.NilError(t, err)
   511  	defer os.RemoveAll(parentPath)
   512  	addition := path.Join(parentPath, "addition")
   513  	err = os.WriteFile(addition, []byte{0x01, 0x01, 0x01}, 0744)
   514  	assert.NilError(t, err)
   515  	modification := path.Join(parentPath, "modification")
   516  	err = os.WriteFile(modification, []byte{0x01, 0x01, 0x01}, 0744)
   517  	assert.NilError(t, err)
   518  
   519  	changes := []Change{
   520  		{Path: "addition", Kind: ChangeAdd},
   521  		{Path: "modification", Kind: ChangeModify},
   522  	}
   523  	size := ChangesSize(parentPath, changes)
   524  	if size != 6 {
   525  		t.Fatalf("Expected 6 bytes of changes, got %d", size)
   526  	}
   527  }
   528  
   529  func checkChanges(expectedChanges, changes []Change, t *testing.T) {
   530  	skip.If(t, runtime.GOOS != "windows" && os.Getuid() != 0, "skipping test that requires root")
   531  	sort.Sort(changesByPath(expectedChanges))
   532  	sort.Sort(changesByPath(changes))
   533  	for i := 0; i < max(len(changes), len(expectedChanges)); i++ {
   534  		if i >= len(expectedChanges) {
   535  			t.Fatalf("unexpected change %s\n", changes[i].String())
   536  		}
   537  		if i >= len(changes) {
   538  			t.Fatalf("no change for expected change %s\n", expectedChanges[i].String())
   539  		}
   540  		if changes[i].Path == expectedChanges[i].Path {
   541  			if changes[i] != expectedChanges[i] {
   542  				t.Fatalf("Wrong change for %s, expected %s, got %s\n", changes[i].Path, changes[i].String(), expectedChanges[i].String())
   543  			}
   544  		} else if changes[i].Path < expectedChanges[i].Path {
   545  			t.Fatalf("unexpected change %s\n", changes[i].String())
   546  		} else {
   547  			t.Fatalf("no change for expected change %s != %s\n", expectedChanges[i].String(), changes[i].String())
   548  		}
   549  	}
   550  }