package main
 
 import (
 	"fmt"
 	"os/exec"
 	"strings"
 	"testing"
 )
 
 // ensure that an added file shows up in docker diff
 func TestDiffFilenameShownInOutput(t *testing.T) {
 	containerCmd := `echo foo > /root/bar`
 	runCmd := exec.Command(dockerBinary, "run", "-d", "busybox", "sh", "-c", containerCmd)
 	cid, _, err := runCommandWithOutput(runCmd)
 	errorOut(err, t, fmt.Sprintf("failed to start the container: %v", err))
 
 	cleanCID := stripTrailingCharacters(cid)
 
 	diffCmd := exec.Command(dockerBinary, "diff", cleanCID)
 	out, _, err := runCommandWithOutput(diffCmd)
 	errorOut(err, t, fmt.Sprintf("failed to run diff: %v %v", out, err))
 
 	found := false
 	for _, line := range strings.Split(out, "\n") {
 		if strings.Contains("A /root/bar", line) {
 			found = true
 			break
 		}
 	}
 	if !found {
 		t.Errorf("couldn't find the new file in docker diff's output: %v", out)
 	}

 	deleteContainer(cleanCID)

 
 	logDone("diff - check if created file shows up")
 }
 
 // test to ensure GH #3840 doesn't occur any more
 func TestDiffEnsureDockerinitFilesAreIgnored(t *testing.T) {
 	// this is a list of files which shouldn't show up in `docker diff`
 	dockerinitFiles := []string{"/etc/resolv.conf", "/etc/hostname", "/etc/hosts", "/.dockerinit", "/.dockerenv"}
 
 	// we might not run into this problem from the first run, so start a few containers
 	for i := 0; i < 20; i++ {
 		containerCmd := `echo foo > /root/bar`
 		runCmd := exec.Command(dockerBinary, "run", "-d", "busybox", "sh", "-c", containerCmd)
 		cid, _, err := runCommandWithOutput(runCmd)
 		errorOut(err, t, fmt.Sprintf("%s", err))
 
 		cleanCID := stripTrailingCharacters(cid)
 
 		diffCmd := exec.Command(dockerBinary, "diff", cleanCID)
 		out, _, err := runCommandWithOutput(diffCmd)
 		errorOut(err, t, fmt.Sprintf("failed to run diff: %v %v", out, err))
 

 		deleteContainer(cleanCID)

 
 		for _, filename := range dockerinitFiles {
 			if strings.Contains(out, filename) {
 				t.Errorf("found file which should've been ignored %v in diff output", filename)
 			}
 		}
 	}
 
 	logDone("diff - check if ignored files show up in diff")
 }

 
 func TestDiffEnsureOnlyKmsgAndPtmx(t *testing.T) {
 	runCmd := exec.Command(dockerBinary, "run", "-d", "busybox", "sleep 0")
 	cid, _, err := runCommandWithOutput(runCmd)
 	errorOut(err, t, fmt.Sprintf("%s", err))
 	cleanCID := stripTrailingCharacters(cid)
 
 	diffCmd := exec.Command(dockerBinary, "diff", cleanCID)
 	out, _, err := runCommandWithOutput(diffCmd)
 	errorOut(err, t, fmt.Sprintf("failed to run diff: %v %v", out, err))

 	deleteContainer(cleanCID)

 
 	expected := map[string]bool{
 		"C /dev":      true,
 		"A /dev/full": true, // busybox
 		"C /dev/ptmx": true, // libcontainer
 		"A /dev/kmsg": true, // lxc
 	}
 
 	for _, line := range strings.Split(out, "\n") {
 		if line != "" && !expected[line] {
 			t.Errorf("'%s' is shown in the diff but shouldn't", line)
 		}
 	}
 }