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|
package atomicwriter
import (
"bytes"
"errors"
"os"
"path/filepath"
"runtime"
"strings"
"syscall"
"testing"
)
// testMode returns the file-mode to use in tests, accounting for Windows
// not supporting full Linux file mode.
func testMode() os.FileMode {
if runtime.GOOS == "windows" {
return 0o666
}
return 0o640
}
// assertFile asserts the given fileName to exist, and to have the expected
// content and mode.
func assertFile(t *testing.T, fileName string, fileContent []byte, expectedMode os.FileMode) {
t.Helper()
actual, err := os.ReadFile(fileName)
if err != nil {
t.Fatalf("Error reading from file: %v", err)
}
if !bytes.Equal(actual, fileContent) {
t.Errorf("Data mismatch, expected %q, got %q", fileContent, actual)
}
st, err := os.Stat(fileName)
if err != nil {
t.Fatalf("Error statting file: %v", err)
}
if st.Mode() != expectedMode {
t.Errorf("Mode mismatched, expected %o, got %o", expectedMode, st.Mode())
}
}
// assertFileCount asserts the given directory has the expected number
// of files, and returns the list of files found.
func assertFileCount(t *testing.T, directory string, expected int) []os.DirEntry {
t.Helper()
files, err := os.ReadDir(directory)
if err != nil {
t.Fatalf("Error reading dir: %v", err)
}
if len(files) != expected {
t.Errorf("Expected %d files, got %d: %v", expected, len(files), files)
}
return files
}
func TestNew(t *testing.T) {
for _, tc := range []string{"normal", "symlinked"} {
tmpDir := t.TempDir()
parentDir := tmpDir
actualParentDir := parentDir
if tc == "symlinked" {
actualParentDir = filepath.Join(tmpDir, "parent-dir")
if err := os.Mkdir(actualParentDir, 0o700); err != nil {
t.Fatal(err)
}
parentDir = filepath.Join(tmpDir, "parent-dir-symlink")
if err := os.Symlink(actualParentDir, parentDir); err != nil {
t.Fatal(err)
}
}
t.Run(tc, func(t *testing.T) {
for _, tc := range []string{"new-file", "existing-file"} {
t.Run(tc, func(t *testing.T) {
fileName := filepath.Join(parentDir, "test.txt")
var origFileCount int
if tc == "existing-file" {
if err := os.WriteFile(fileName, []byte("original content"), testMode()); err != nil {
t.Fatalf("Error writing file: %v", err)
}
origFileCount = 1
}
writer, err := New(fileName, testMode())
if writer == nil {
t.Errorf("Writer is nil")
}
if err != nil {
t.Fatalf("Error creating new atomicwriter: %v", err)
}
files := assertFileCount(t, actualParentDir, origFileCount+1)
if tmpFileName := files[0].Name(); !strings.HasPrefix(tmpFileName, ".tmp-test.txt") {
t.Errorf("Unexpected file name for temp-file: %s", tmpFileName)
}
// Closing the writer without writing should clean up the temp-file,
// and should not replace the destination file.
if err = writer.Close(); err != nil {
t.Errorf("Error closing writer: %v", err)
}
assertFileCount(t, actualParentDir, origFileCount)
if tc == "existing-file" {
assertFile(t, fileName, []byte("original content"), testMode())
}
})
}
})
}
}
func TestNewInvalid(t *testing.T) {
t.Run("missing target dir", func(t *testing.T) {
tmpDir := t.TempDir()
fileName := filepath.Join(tmpDir, "missing-dir", "test.txt")
writer, err := New(fileName, testMode())
if writer != nil {
t.Errorf("Should not have created writer")
}
if !errors.Is(err, os.ErrNotExist) {
t.Errorf("Should produce a 'not found' error, but got %[1]T (%[1]v)", err)
}
})
t.Run("target dir is not a directory", func(t *testing.T) {
tmpDir := t.TempDir()
parentPath := filepath.Join(tmpDir, "not-a-dir")
err := os.WriteFile(parentPath, nil, testMode())
if err != nil {
t.Fatalf("Error writing file: %v", err)
}
fileName := filepath.Join(parentPath, "new-file.txt")
writer, err := New(fileName, testMode())
if writer != nil {
t.Errorf("Should not have created writer")
}
// This should match the behavior of os.WriteFile, which returns a [os.PathError] with [syscall.ENOTDIR].
if !errors.Is(err, syscall.ENOTDIR) {
t.Errorf("Should produce a 'not a directory' error, but got %[1]T (%[1]v)", err)
}
})
t.Run("empty filename", func(t *testing.T) {
writer, err := New("", testMode())
if writer != nil {
t.Errorf("Should not have created writer")
}
if err == nil || err.Error() != "file name is empty" {
t.Errorf("Should produce a 'file name is empty' error, but got %[1]T (%[1]v)", err)
}
})
t.Run("directory", func(t *testing.T) {
tmpDir := t.TempDir()
writer, err := New(tmpDir, testMode())
if writer != nil {
t.Errorf("Should not have created writer")
}
if err == nil || err.Error() != "cannot write to a directory" {
t.Errorf("Should produce a 'cannot write to a directory' error, but got %[1]T (%[1]v)", err)
}
})
t.Run("symlinked file", func(t *testing.T) {
tmpDir := t.TempDir()
linkTarget := filepath.Join(tmpDir, "symlink-target")
if err := os.WriteFile(linkTarget, []byte("orig content"), testMode()); err != nil {
t.Fatal(err)
}
fileName := filepath.Join(tmpDir, "symlinked-file")
if err := os.Symlink(linkTarget, fileName); err != nil {
t.Fatal(err)
}
writer, err := New(fileName, testMode())
if writer != nil {
t.Errorf("Should not have created writer")
}
if err == nil || err.Error() != "cannot write to a symbolic link directly" {
t.Errorf("Should produce a 'cannot write to a symbolic link directly' error, but got %[1]T (%[1]v)", err)
}
})
}
func TestWriteFile(t *testing.T) {
t.Run("empty filename", func(t *testing.T) {
err := WriteFile("", nil, testMode())
if err == nil || err.Error() != "file name is empty" {
t.Errorf("Should produce a 'file name is empty' error, but got %[1]T (%[1]v)", err)
}
})
t.Run("write to directory", func(t *testing.T) {
err := WriteFile(t.TempDir(), nil, testMode())
if err == nil || err.Error() != "cannot write to a directory" {
t.Errorf("Should produce a 'cannot write to a directory' error, but got %[1]T (%[1]v)", err)
}
})
t.Run("write to file", func(t *testing.T) {
tmpDir := t.TempDir()
fileName := filepath.Join(tmpDir, "test.txt")
fileContent := []byte("file content")
fileMode := testMode()
if err := WriteFile(fileName, fileContent, fileMode); err != nil {
t.Fatalf("Error writing to file: %v", err)
}
assertFile(t, fileName, fileContent, fileMode)
assertFileCount(t, tmpDir, 1)
})
t.Run("missing parent directory", func(t *testing.T) {
tmpDir := t.TempDir()
fileName := filepath.Join(tmpDir, "missing-dir", "test.txt")
fileContent := []byte("file content")
fileMode := testMode()
if err := WriteFile(fileName, fileContent, fileMode); !errors.Is(err, os.ErrNotExist) {
t.Errorf("Should produce a 'not found' error, but got %[1]T (%[1]v)", err)
}
assertFileCount(t, tmpDir, 0)
})
t.Run("symlinked file", func(t *testing.T) {
tmpDir := t.TempDir()
linkTarget := filepath.Join(tmpDir, "symlink-target")
originalContent := []byte("original content")
fileMode := testMode()
if err := os.WriteFile(linkTarget, originalContent, fileMode); err != nil {
t.Fatal(err)
}
if err := os.Symlink(linkTarget, filepath.Join(tmpDir, "symlinked-file")); err != nil {
t.Fatal(err)
}
origFileCount := 2
assertFileCount(t, tmpDir, origFileCount)
fileName := filepath.Join(tmpDir, "symlinked-file")
err := WriteFile(fileName, []byte("new content"), testMode())
if err == nil || err.Error() != "cannot write to a symbolic link directly" {
t.Errorf("Should produce a 'cannot write to a symbolic link directly' error, but got %[1]T (%[1]v)", err)
}
assertFile(t, linkTarget, originalContent, fileMode)
assertFileCount(t, tmpDir, origFileCount)
})
t.Run("symlinked directory", func(t *testing.T) {
tmpDir := t.TempDir()
actualParentDir := filepath.Join(tmpDir, "parent-dir")
if err := os.Mkdir(actualParentDir, 0o700); err != nil {
t.Fatal(err)
}
actualTargetFile := filepath.Join(actualParentDir, "target-file")
if err := os.WriteFile(actualTargetFile, []byte("orig content"), testMode()); err != nil {
t.Fatal(err)
}
parentDir := filepath.Join(tmpDir, "parent-dir-symlink")
if err := os.Symlink(actualParentDir, parentDir); err != nil {
t.Fatal(err)
}
origFileCount := 1
assertFileCount(t, actualParentDir, origFileCount)
fileName := filepath.Join(parentDir, "target-file")
fileContent := []byte("new content")
fileMode := testMode()
if err := WriteFile(fileName, fileContent, fileMode); err != nil {
t.Fatalf("Error writing to file: %v", err)
}
assertFile(t, fileName, fileContent, fileMode)
assertFile(t, actualTargetFile, fileContent, fileMode)
assertFileCount(t, actualParentDir, origFileCount)
})
}
func TestWriteSetCommit(t *testing.T) {
tmpDir := t.TempDir()
if err := os.Mkdir(filepath.Join(tmpDir, "tmp"), 0o700); err != nil {
t.Fatalf("Error creating tmp directory: %s", err)
}
targetDir := filepath.Join(tmpDir, "target")
ws, err := NewWriteSet(filepath.Join(tmpDir, "tmp"))
if err != nil {
t.Fatalf("Error creating atomic write set: %s", err)
}
fileContent := []byte("file content")
fileMode := testMode()
if err := ws.WriteFile("foo", fileContent, fileMode); err != nil {
t.Fatalf("Error writing to file: %v", err)
}
if _, err := os.ReadFile(filepath.Join(targetDir, "foo")); err == nil {
t.Fatalf("Expected error reading file where should not exist")
}
if err := ws.Commit(targetDir); err != nil {
t.Fatalf("Error committing file: %s", err)
}
assertFile(t, filepath.Join(targetDir, "foo"), fileContent, fileMode)
assertFileCount(t, targetDir, 1)
}
func TestWriteSetCancel(t *testing.T) {
tmpDir := t.TempDir()
if err := os.Mkdir(filepath.Join(tmpDir, "tmp"), 0o700); err != nil {
t.Fatalf("Error creating tmp directory: %s", err)
}
ws, err := NewWriteSet(filepath.Join(tmpDir, "tmp"))
if err != nil {
t.Fatalf("Error creating atomic write set: %s", err)
}
fileContent := []byte("file content")
fileMode := testMode()
if err := ws.WriteFile("foo", fileContent, fileMode); err != nil {
t.Fatalf("Error writing to file: %v", err)
}
if err := ws.Cancel(); err != nil {
t.Fatalf("Error committing file: %s", err)
}
if _, err := os.ReadFile(filepath.Join(tmpDir, "target", "foo")); err == nil {
t.Fatalf("Expected error reading file where should not exist")
} else if !errors.Is(err, os.ErrNotExist) {
t.Fatalf("Unexpected error reading file: %s", err)
}
assertFileCount(t, filepath.Join(tmpDir, "tmp"), 0)
}
|
