moby/pkg/fileutils/fileutils_test.go

package fileutils

import (
	"os"
	"testing"
)

// Reading a symlink to a directory must return the directory
func TestReadSymlinkedDirectoryExistingDirectory(t *testing.T) {
	var err error
	if err = os.Mkdir("/tmp/testReadSymlinkToExistingDirectory", 0777); err != nil {
		t.Errorf("failed to create directory: %s", err)
	}

	if err = os.Symlink("/tmp/testReadSymlinkToExistingDirectory", "/tmp/dirLinkTest"); err != nil {
		t.Errorf("failed to create symlink: %s", err)
	}

	var path string
	if path, err = ReadSymlinkedDirectory("/tmp/dirLinkTest"); err != nil {
		t.Fatalf("failed to read symlink to directory: %s", err)
	}

	if path != "/tmp/testReadSymlinkToExistingDirectory" {
		t.Fatalf("symlink returned unexpected directory: %s", path)
	}

	if err = os.Remove("/tmp/testReadSymlinkToExistingDirectory"); err != nil {
		t.Errorf("failed to remove temporary directory: %s", err)
	}

	if err = os.Remove("/tmp/dirLinkTest"); err != nil {
		t.Errorf("failed to remove symlink: %s", err)
	}
}

// Reading a non-existing symlink must fail
func TestReadSymlinkedDirectoryNonExistingSymlink(t *testing.T) {
	var path string
	var err error
	if path, err = ReadSymlinkedDirectory("/tmp/test/foo/Non/ExistingPath"); err == nil {
		t.Fatalf("error expected for non-existing symlink")
	}

	if path != "" {
		t.Fatalf("expected empty path, but '%s' was returned", path)
	}
}

// Reading a symlink to a file must fail
func TestReadSymlinkedDirectoryToFile(t *testing.T) {
	var err error
	var file *os.File

	if file, err = os.Create("/tmp/testReadSymlinkToFile"); err != nil {
		t.Fatalf("failed to create file: %s", err)
	}

	file.Close()

	if err = os.Symlink("/tmp/testReadSymlinkToFile", "/tmp/fileLinkTest"); err != nil {
		t.Errorf("failed to create symlink: %s", err)
	}

	var path string
	if path, err = ReadSymlinkedDirectory("/tmp/fileLinkTest"); err == nil {
		t.Fatalf("ReadSymlinkedDirectory on a symlink to a file should've failed")
	}

	if path != "" {
		t.Fatalf("path should've been empty: %s", path)
	}

	if err = os.Remove("/tmp/testReadSymlinkToFile"); err != nil {
		t.Errorf("failed to remove file: %s", err)
	}

	if err = os.Remove("/tmp/fileLinkTest"); err != nil {
		t.Errorf("failed to remove symlink: %s", err)
	}
}