go/src/testing/fstest/testfs.go

// 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 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 either the first error or a
// list of errors. Use [errors.Is] or [errors.As] to inspect.
//
// 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 { … }

func testFS(fsys fs.FS, expected ...string) error { … }

type fsTester …

// errorf adds an error to the list of errors.
func (t *fsTester) errorf(format string, args ...any) { … }

func (t *fsTester) openDir(dir string) fs.ReadDirFile { … }

// 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) { … }

// formatEntry formats an fs.DirEntry into a string for error messages and comparison.
func formatEntry(entry fs.DirEntry) string { … }

// formatInfoEntry formats an fs.FileInfo into a string like the result of formatEntry, for error messages and comparison.
func formatInfoEntry(info fs.FileInfo) string { … }

// formatInfo formats an fs.FileInfo into a string for error messages and comparison.
func formatInfo(info fs.FileInfo) string { … }

// checkGlob checks that various glob patterns work if the file system implements GlobFS.
func (t *fsTester) checkGlob(dir string, list []fs.DirEntry) { … }

// 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) { … }

// 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) { … }

// checkFile checks that basic file reading works correctly.
func (t *fsTester) checkFile(file string) { … }

func (t *fsTester) checkFileRead(file, desc string, data1, data2 []byte) { … }

// checkBadPath checks that various invalid forms of file's name cannot be opened using t.fsys.Open.
func (t *fsTester) checkOpen(file string) { … }

// 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) { … }