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-rw-r--r--src/testing/fstest/testfs.go614
1 files changed, 614 insertions, 0 deletions
diff --git a/src/testing/fstest/testfs.go b/src/testing/fstest/testfs.go
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+++ b/src/testing/fstest/testfs.go
@@ -0,0 +1,614 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package fstest implements support for testing implementations and users of file systems.
+package fstest
+
+import (
+ "errors"
+ "fmt"
+ "io"
+ "io/fs"
+ "io/ioutil"
+ "path"
+ "reflect"
+ "sort"
+ "strings"
+ "testing/iotest"
+)
+
+// TestFS tests a file system implementation.
+// It walks the entire tree of files in fsys,
+// opening and checking that each file behaves correctly.
+// It also checks that the file system contains at least the expected files.
+// As a special case, if no expected files are listed, fsys must be empty.
+// Otherwise, fsys must only contain at least the listed files: it can also contain others.
+// The contents of fsys must not change concurrently with TestFS.
+//
+// If TestFS finds any misbehaviors, it returns an error reporting all of them.
+// The error text spans multiple lines, one per detected misbehavior.
+//
+// Typical usage inside a test is:
+//
+// if err := fstest.TestFS(myFS, "file/that/should/be/present"); err != nil {
+// t.Fatal(err)
+// }
+//
+func TestFS(fsys fs.FS, expected ...string) error {
+ if err := testFS(fsys, expected...); err != nil {
+ return err
+ }
+ for _, name := range expected {
+ if i := strings.Index(name, "/"); i >= 0 {
+ dir, dirSlash := name[:i], name[:i+1]
+ var subExpected []string
+ for _, name := range expected {
+ if strings.HasPrefix(name, dirSlash) {
+ subExpected = append(subExpected, name[len(dirSlash):])
+ }
+ }
+ sub, err := fs.Sub(fsys, dir)
+ if err != nil {
+ return err
+ }
+ if err := testFS(sub, subExpected...); err != nil {
+ return fmt.Errorf("testing fs.Sub(fsys, %s): %v", dir, err)
+ }
+ break // one sub-test is enough
+ }
+ }
+ return nil
+}
+
+func testFS(fsys fs.FS, expected ...string) error {
+ t := fsTester{fsys: fsys}
+ t.checkDir(".")
+ t.checkOpen(".")
+ found := make(map[string]bool)
+ for _, dir := range t.dirs {
+ found[dir] = true
+ }
+ for _, file := range t.files {
+ found[file] = true
+ }
+ delete(found, ".")
+ if len(expected) == 0 && len(found) > 0 {
+ var list []string
+ for k := range found {
+ if k != "." {
+ list = append(list, k)
+ }
+ }
+ sort.Strings(list)
+ if len(list) > 15 {
+ list = append(list[:10], "...")
+ }
+ t.errorf("expected empty file system but found files:\n%s", strings.Join(list, "\n"))
+ }
+ for _, name := range expected {
+ if !found[name] {
+ t.errorf("expected but not found: %s", name)
+ }
+ }
+ if len(t.errText) == 0 {
+ return nil
+ }
+ return errors.New("TestFS found errors:\n" + string(t.errText))
+}
+
+// An fsTester holds state for running the test.
+type fsTester struct {
+ fsys fs.FS
+ errText []byte
+ dirs []string
+ files []string
+}
+
+// errorf adds an error line to errText.
+func (t *fsTester) errorf(format string, args ...interface{}) {
+ if len(t.errText) > 0 {
+ t.errText = append(t.errText, '\n')
+ }
+ t.errText = append(t.errText, fmt.Sprintf(format, args...)...)
+}
+
+func (t *fsTester) openDir(dir string) fs.ReadDirFile {
+ f, err := t.fsys.Open(dir)
+ if err != nil {
+ t.errorf("%s: Open: %v", dir, err)
+ return nil
+ }
+ d, ok := f.(fs.ReadDirFile)
+ if !ok {
+ f.Close()
+ t.errorf("%s: Open returned File type %T, not a fs.ReadDirFile", dir, f)
+ return nil
+ }
+ return d
+}
+
+// checkDir checks the directory dir, which is expected to exist
+// (it is either the root or was found in a directory listing with IsDir true).
+func (t *fsTester) checkDir(dir string) {
+ // Read entire directory.
+ t.dirs = append(t.dirs, dir)
+ d := t.openDir(dir)
+ if d == nil {
+ return
+ }
+ list, err := d.ReadDir(-1)
+ if err != nil {
+ d.Close()
+ t.errorf("%s: ReadDir(-1): %v", dir, err)
+ return
+ }
+
+ // Check all children.
+ var prefix string
+ if dir == "." {
+ prefix = ""
+ } else {
+ prefix = dir + "/"
+ }
+ for _, info := range list {
+ name := info.Name()
+ switch {
+ case name == ".", name == "..", name == "":
+ t.errorf("%s: ReadDir: child has invalid name: %#q", dir, name)
+ continue
+ case strings.Contains(name, "/"):
+ t.errorf("%s: ReadDir: child name contains slash: %#q", dir, name)
+ continue
+ case strings.Contains(name, `\`):
+ t.errorf("%s: ReadDir: child name contains backslash: %#q", dir, name)
+ continue
+ }
+ path := prefix + name
+ t.checkStat(path, info)
+ t.checkOpen(path)
+ if info.IsDir() {
+ t.checkDir(path)
+ } else {
+ t.checkFile(path)
+ }
+ }
+
+ // Check ReadDir(-1) at EOF.
+ list2, err := d.ReadDir(-1)
+ if len(list2) > 0 || err != nil {
+ d.Close()
+ t.errorf("%s: ReadDir(-1) at EOF = %d entries, %v, wanted 0 entries, nil", dir, len(list2), err)
+ return
+ }
+
+ // Check ReadDir(1) at EOF (different results).
+ list2, err = d.ReadDir(1)
+ if len(list2) > 0 || err != io.EOF {
+ d.Close()
+ t.errorf("%s: ReadDir(1) at EOF = %d entries, %v, wanted 0 entries, EOF", dir, len(list2), err)
+ return
+ }
+
+ // Check that close does not report an error.
+ if err := d.Close(); err != nil {
+ t.errorf("%s: Close: %v", dir, err)
+ }
+
+ // Check that closing twice doesn't crash.
+ // The return value doesn't matter.
+ d.Close()
+
+ // Reopen directory, read a second time, make sure contents match.
+ if d = t.openDir(dir); d == nil {
+ return
+ }
+ defer d.Close()
+ list2, err = d.ReadDir(-1)
+ if err != nil {
+ t.errorf("%s: second Open+ReadDir(-1): %v", dir, err)
+ return
+ }
+ t.checkDirList(dir, "first Open+ReadDir(-1) vs second Open+ReadDir(-1)", list, list2)
+
+ // Reopen directory, read a third time in pieces, make sure contents match.
+ if d = t.openDir(dir); d == nil {
+ return
+ }
+ defer d.Close()
+ list2 = nil
+ for {
+ n := 1
+ if len(list2) > 0 {
+ n = 2
+ }
+ frag, err := d.ReadDir(n)
+ if len(frag) > n {
+ t.errorf("%s: third Open: ReadDir(%d) after %d: %d entries (too many)", dir, n, len(list2), len(frag))
+ return
+ }
+ list2 = append(list2, frag...)
+ if err == io.EOF {
+ break
+ }
+ if err != nil {
+ t.errorf("%s: third Open: ReadDir(%d) after %d: %v", dir, n, len(list2), err)
+ return
+ }
+ if n == 0 {
+ t.errorf("%s: third Open: ReadDir(%d) after %d: 0 entries but nil error", dir, n, len(list2))
+ return
+ }
+ }
+ t.checkDirList(dir, "first Open+ReadDir(-1) vs third Open+ReadDir(1,2) loop", list, list2)
+
+ // If fsys has ReadDir, check that it matches and is sorted.
+ if fsys, ok := t.fsys.(fs.ReadDirFS); ok {
+ list2, err := fsys.ReadDir(dir)
+ if err != nil {
+ t.errorf("%s: fsys.ReadDir: %v", dir, err)
+ return
+ }
+ t.checkDirList(dir, "first Open+ReadDir(-1) vs fsys.ReadDir", list, list2)
+
+ for i := 0; i+1 < len(list2); i++ {
+ if list2[i].Name() >= list2[i+1].Name() {
+ t.errorf("%s: fsys.ReadDir: list not sorted: %s before %s", dir, list2[i].Name(), list2[i+1].Name())
+ }
+ }
+ }
+
+ // Check fs.ReadDir as well.
+ list2, err = fs.ReadDir(t.fsys, dir)
+ if err != nil {
+ t.errorf("%s: fs.ReadDir: %v", dir, err)
+ return
+ }
+ t.checkDirList(dir, "first Open+ReadDir(-1) vs fs.ReadDir", list, list2)
+
+ for i := 0; i+1 < len(list2); i++ {
+ if list2[i].Name() >= list2[i+1].Name() {
+ t.errorf("%s: fs.ReadDir: list not sorted: %s before %s", dir, list2[i].Name(), list2[i+1].Name())
+ }
+ }
+
+ t.checkGlob(dir, list)
+}
+
+// formatEntry formats an fs.DirEntry into a string for error messages and comparison.
+func formatEntry(entry fs.DirEntry) string {
+ return fmt.Sprintf("%s IsDir=%v Type=%v", entry.Name(), entry.IsDir(), entry.Type())
+}
+
+// formatInfoEntry formats an fs.FileInfo into a string like the result of formatEntry, for error messages and comparison.
+func formatInfoEntry(info fs.FileInfo) string {
+ return fmt.Sprintf("%s IsDir=%v Type=%v", info.Name(), info.IsDir(), info.Mode().Type())
+}
+
+// formatInfo formats an fs.FileInfo into a string for error messages and comparison.
+func formatInfo(info fs.FileInfo) string {
+ return fmt.Sprintf("%s IsDir=%v Mode=%v Size=%d ModTime=%v", info.Name(), info.IsDir(), info.Mode(), info.Size(), info.ModTime())
+}
+
+// checkGlob checks that various glob patterns work if the file system implements GlobFS.
+func (t *fsTester) checkGlob(dir string, list []fs.DirEntry) {
+ if _, ok := t.fsys.(fs.GlobFS); !ok {
+ return
+ }
+
+ // Make a complex glob pattern prefix that only matches dir.
+ var glob string
+ if dir != "." {
+ elem := strings.Split(dir, "/")
+ for i, e := range elem {
+ var pattern []rune
+ for j, r := range e {
+ if r == '*' || r == '?' || r == '\\' || r == '[' {
+ pattern = append(pattern, '\\', r)
+ continue
+ }
+ switch (i + j) % 5 {
+ case 0:
+ pattern = append(pattern, r)
+ case 1:
+ pattern = append(pattern, '[', r, ']')
+ case 2:
+ pattern = append(pattern, '[', r, '-', r, ']')
+ case 3:
+ pattern = append(pattern, '[', '\\', r, ']')
+ case 4:
+ pattern = append(pattern, '[', '\\', r, '-', '\\', r, ']')
+ }
+ }
+ elem[i] = string(pattern)
+ }
+ glob = strings.Join(elem, "/") + "/"
+ }
+
+ // Test that malformed patterns are detected.
+ // The error is likely path.ErrBadPattern but need not be.
+ if _, err := t.fsys.(fs.GlobFS).Glob(glob + "nonexist/[]"); err == nil {
+ t.errorf("%s: Glob(%#q): bad pattern not detected", dir, glob+"nonexist/[]")
+ }
+
+ // Try to find a letter that appears in only some of the final names.
+ c := rune('a')
+ for ; c <= 'z'; c++ {
+ have, haveNot := false, false
+ for _, d := range list {
+ if strings.ContainsRune(d.Name(), c) {
+ have = true
+ } else {
+ haveNot = true
+ }
+ }
+ if have && haveNot {
+ break
+ }
+ }
+ if c > 'z' {
+ c = 'a'
+ }
+ glob += "*" + string(c) + "*"
+
+ var want []string
+ for _, d := range list {
+ if strings.ContainsRune(d.Name(), c) {
+ want = append(want, path.Join(dir, d.Name()))
+ }
+ }
+
+ names, err := t.fsys.(fs.GlobFS).Glob(glob)
+ if err != nil {
+ t.errorf("%s: Glob(%#q): %v", dir, glob, err)
+ return
+ }
+ if reflect.DeepEqual(want, names) {
+ return
+ }
+
+ if !sort.StringsAreSorted(names) {
+ t.errorf("%s: Glob(%#q): unsorted output:\n%s", dir, glob, strings.Join(names, "\n"))
+ sort.Strings(names)
+ }
+
+ var problems []string
+ for len(want) > 0 || len(names) > 0 {
+ switch {
+ case len(want) > 0 && len(names) > 0 && want[0] == names[0]:
+ want, names = want[1:], names[1:]
+ case len(want) > 0 && (len(names) == 0 || want[0] < names[0]):
+ problems = append(problems, "missing: "+want[0])
+ want = want[1:]
+ default:
+ problems = append(problems, "extra: "+names[0])
+ names = names[1:]
+ }
+ }
+ t.errorf("%s: Glob(%#q): wrong output:\n%s", dir, glob, strings.Join(problems, "\n"))
+}
+
+// checkStat checks that a direct stat of path matches entry,
+// which was found in the parent's directory listing.
+func (t *fsTester) checkStat(path string, entry fs.DirEntry) {
+ file, err := t.fsys.Open(path)
+ if err != nil {
+ t.errorf("%s: Open: %v", path, err)
+ return
+ }
+ info, err := file.Stat()
+ file.Close()
+ if err != nil {
+ t.errorf("%s: Stat: %v", path, err)
+ return
+ }
+ fentry := formatEntry(entry)
+ fientry := formatInfoEntry(info)
+ // Note: mismatch here is OK for symlink, because Open dereferences symlink.
+ if fentry != fientry && entry.Type()&fs.ModeSymlink == 0 {
+ t.errorf("%s: mismatch:\n\tentry = %s\n\tfile.Stat() = %s", path, fentry, fientry)
+ }
+
+ einfo, err := entry.Info()
+ if err != nil {
+ t.errorf("%s: entry.Info: %v", path, err)
+ return
+ }
+ finfo := formatInfo(info)
+ if entry.Type()&fs.ModeSymlink != 0 {
+ // For symlink, just check that entry.Info matches entry on common fields.
+ // Open deferences symlink, so info itself may differ.
+ feentry := formatInfoEntry(einfo)
+ if fentry != feentry {
+ t.errorf("%s: mismatch\n\tentry = %s\n\tentry.Info() = %s\n", path, fentry, feentry)
+ }
+ } else {
+ feinfo := formatInfo(einfo)
+ if feinfo != finfo {
+ t.errorf("%s: mismatch:\n\tentry.Info() = %s\n\tfile.Stat() = %s\n", path, feinfo, finfo)
+ }
+ }
+
+ // Stat should be the same as Open+Stat, even for symlinks.
+ info2, err := fs.Stat(t.fsys, path)
+ if err != nil {
+ t.errorf("%s: fs.Stat: %v", path, err)
+ return
+ }
+ finfo2 := formatInfo(info2)
+ if finfo2 != finfo {
+ t.errorf("%s: fs.Stat(...) = %s\n\twant %s", path, finfo2, finfo)
+ }
+
+ if fsys, ok := t.fsys.(fs.StatFS); ok {
+ info2, err := fsys.Stat(path)
+ if err != nil {
+ t.errorf("%s: fsys.Stat: %v", path, err)
+ return
+ }
+ finfo2 := formatInfo(info2)
+ if finfo2 != finfo {
+ t.errorf("%s: fsys.Stat(...) = %s\n\twant %s", path, finfo2, finfo)
+ }
+ }
+}
+
+// checkDirList checks that two directory lists contain the same files and file info.
+// The order of the lists need not match.
+func (t *fsTester) checkDirList(dir, desc string, list1, list2 []fs.DirEntry) {
+ old := make(map[string]fs.DirEntry)
+ checkMode := func(entry fs.DirEntry) {
+ if entry.IsDir() != (entry.Type()&fs.ModeDir != 0) {
+ if entry.IsDir() {
+ t.errorf("%s: ReadDir returned %s with IsDir() = true, Type() & ModeDir = 0", dir, entry.Name())
+ } else {
+ t.errorf("%s: ReadDir returned %s with IsDir() = false, Type() & ModeDir = ModeDir", dir, entry.Name())
+ }
+ }
+ }
+
+ for _, entry1 := range list1 {
+ old[entry1.Name()] = entry1
+ checkMode(entry1)
+ }
+
+ var diffs []string
+ for _, entry2 := range list2 {
+ entry1 := old[entry2.Name()]
+ if entry1 == nil {
+ checkMode(entry2)
+ diffs = append(diffs, "+ "+formatEntry(entry2))
+ continue
+ }
+ if formatEntry(entry1) != formatEntry(entry2) {
+ diffs = append(diffs, "- "+formatEntry(entry1), "+ "+formatEntry(entry2))
+ }
+ delete(old, entry2.Name())
+ }
+ for _, entry1 := range old {
+ diffs = append(diffs, "- "+formatEntry(entry1))
+ }
+
+ if len(diffs) == 0 {
+ return
+ }
+
+ sort.Slice(diffs, func(i, j int) bool {
+ fi := strings.Fields(diffs[i])
+ fj := strings.Fields(diffs[j])
+ // sort by name (i < j) and then +/- (j < i, because + < -)
+ return fi[1]+" "+fj[0] < fj[1]+" "+fi[0]
+ })
+
+ t.errorf("%s: diff %s:\n\t%s", dir, desc, strings.Join(diffs, "\n\t"))
+}
+
+// checkFile checks that basic file reading works correctly.
+func (t *fsTester) checkFile(file string) {
+ t.files = append(t.files, file)
+
+ // Read entire file.
+ f, err := t.fsys.Open(file)
+ if err != nil {
+ t.errorf("%s: Open: %v", file, err)
+ return
+ }
+
+ data, err := ioutil.ReadAll(f)
+ if err != nil {
+ f.Close()
+ t.errorf("%s: Open+ReadAll: %v", file, err)
+ return
+ }
+
+ if err := f.Close(); err != nil {
+ t.errorf("%s: Close: %v", file, err)
+ }
+
+ // Check that closing twice doesn't crash.
+ // The return value doesn't matter.
+ f.Close()
+
+ // Check that ReadFile works if present.
+ if fsys, ok := t.fsys.(fs.ReadFileFS); ok {
+ data2, err := fsys.ReadFile(file)
+ if err != nil {
+ t.errorf("%s: fsys.ReadFile: %v", file, err)
+ return
+ }
+ t.checkFileRead(file, "ReadAll vs fsys.ReadFile", data, data2)
+
+ t.checkBadPath(file, "ReadFile",
+ func(name string) error { _, err := fsys.ReadFile(name); return err })
+ }
+
+ // Check that fs.ReadFile works with t.fsys.
+ data2, err := fs.ReadFile(t.fsys, file)
+ if err != nil {
+ t.errorf("%s: fs.ReadFile: %v", file, err)
+ return
+ }
+ t.checkFileRead(file, "ReadAll vs fs.ReadFile", data, data2)
+
+ // Use iotest.TestReader to check small reads, Seek, ReadAt.
+ f, err = t.fsys.Open(file)
+ if err != nil {
+ t.errorf("%s: second Open: %v", file, err)
+ return
+ }
+ defer f.Close()
+ if err := iotest.TestReader(f, data); err != nil {
+ t.errorf("%s: failed TestReader:\n\t%s", file, strings.ReplaceAll(err.Error(), "\n", "\n\t"))
+ }
+}
+
+func (t *fsTester) checkFileRead(file, desc string, data1, data2 []byte) {
+ if string(data1) != string(data2) {
+ t.errorf("%s: %s: different data returned\n\t%q\n\t%q", file, desc, data1, data2)
+ return
+ }
+}
+
+// checkBadPath checks that various invalid forms of file's name cannot be opened using t.fsys.Open.
+func (t *fsTester) checkOpen(file string) {
+ t.checkBadPath(file, "Open", func(file string) error {
+ f, err := t.fsys.Open(file)
+ if err == nil {
+ f.Close()
+ }
+ return err
+ })
+}
+
+// checkBadPath checks that various invalid forms of file's name cannot be opened using open.
+func (t *fsTester) checkBadPath(file string, desc string, open func(string) error) {
+ bad := []string{
+ "/" + file,
+ file + "/.",
+ }
+ if file == "." {
+ bad = append(bad, "/")
+ }
+ if i := strings.Index(file, "/"); i >= 0 {
+ bad = append(bad,
+ file[:i]+"//"+file[i+1:],
+ file[:i]+"/./"+file[i+1:],
+ file[:i]+`\`+file[i+1:],
+ file[:i]+"/../"+file,
+ )
+ }
+ if i := strings.LastIndex(file, "/"); i >= 0 {
+ bad = append(bad,
+ file[:i]+"//"+file[i+1:],
+ file[:i]+"/./"+file[i+1:],
+ file[:i]+`\`+file[i+1:],
+ file+"/../"+file[i+1:],
+ )
+ }
+
+ for _, b := range bad {
+ if err := open(b); err == nil {
+ t.errorf("%s: %s(%s) succeeded, want error", file, desc, b)
+ }
+ }
+}