lnd/fn/io_test.go
z017 0652cbd4a1
fn: add synchronous write file
The fn.WriteFile writes data like os.WriteFile but in sync mode.
Also adds a behaviour flag that enables removal of file on error.

Co-authored-by: Maurice Poirrier Chuden <mauricepoirrier@gmail.com>
Co-authored-by: Greg Weber <1183+gregwebs@users.noreply.github.com>
2024-12-16 11:16:00 -03:00

97 lines
2.5 KiB
Go

package fn
import (
"os"
"testing"
"github.com/stretchr/testify/require"
)
var (
data1 = "The network is robust in its unstructured simplicity."
data2 = "Nodes work all at once with little coordination."
)
// TestWriteFile uses same scenario of ioutil asserting the content created and
// stored on new file with the original one.
func TestWriteFile(t *testing.T) {
t.Parallel()
f, deferred := ensureTempfile(t)
filename := f.Name()
defer deferred()
// Write file.
err := WriteFile(filename, []byte(data2), 0644)
require.NoError(t, err, "couldn't write file")
ensureFileContents(t, filename, data2)
// Overwrite file.
err = WriteFile(filename, []byte(data1), 0644)
require.NoError(t, err, "couldn't overwrite file")
ensureFileContents(t, filename, data1)
// Change file permission to read-only.
err = os.Chmod(filename, 0444)
require.NoError(t, err, "couldn't change file to read-only")
// Write must fail and keep the file.
err = WriteFile(filename, []byte(data2), 0644)
require.Error(t, err, "shouldn't write a read-only file")
_, err = os.Stat(filename)
require.NoError(t, err, "shouldn't remove file on error")
ensureFileContents(t, filename, data1)
}
func TestWriteFileRemove(t *testing.T) {
t.Parallel()
f, deferred := ensureTempfile(t)
filename := f.Name()
defer deferred()
// Write file.
err := WriteFileRemove(filename, []byte(data2), 0644)
require.NoError(t, err, "couldn't write file")
ensureFileContents(t, filename, data2)
// Overwrite file.
err = WriteFileRemove(filename, []byte(data1), 0644)
require.NoError(t, err, "couldn't overwrite file")
ensureFileContents(t, filename, data1)
// Change file permission to read-only.
err = os.Chmod(filename, 0444)
require.NoError(t, err, "couldn't change file to read-only")
// Write must fail and remove the file.
err = WriteFileRemove(filename, []byte(data2), 0644)
require.Error(t, err, "shouldn't write a read-only file")
_, err = os.Stat(filename)
require.ErrorContains(
t, err, "no such file or directory",
"should remove file on error",
)
}
func ensureTempfile(t *testing.T) (*os.File, func()) {
t.Helper()
f, err := os.CreateTemp("", "fn-io-test-TestWriteFile")
require.NoError(t, err, "couldn't create temporary file")
return f, func() {
f.Close()
os.Remove(f.Name())
}
}
func ensureFileContents(t *testing.T, filename string, data string) {
t.Helper()
contents, err := os.ReadFile(filename)
require.NoError(t, err, "couldn't read file")
require.Equal(t, data, string(contents))
}