}
        '''.stripIndent()

        when:
        run 'sync'

        then:
        file('dest').assertHasDescendants(
            'dir1/file1.txt',
            'dir2/subdir/file2.txt',
            'dir2/file3.txt',
            'emptyDir'
        )
    }

    def 'preserve keeps specified files in destDir'() {
        given:
        defaultSourceFileTree()

	// Create subdirs.
	subdir := filepath.Join(dir, prog+"dir"+tag)
	if err := os.Mkdir(subdir, 0777); err != nil {
		t.Fatalf("can't create outdir %s: %v", subdir, err)
	}
	depdir := filepath.Join(subdir, "dep")
	if err := os.Mkdir(depdir, 0777); err != nil {
		t.Fatalf("can't create outdir %s: %v", depdir, err)
	}

	// Emit program.

}

// adbCopyTree copies testdata, go.mod, go.sum files from subdir
// and from parent directories all the way up to the root of subdir.
// go.mod and go.sum files are needed for the go tool modules queries,
// and the testdata directories for tests.  It is common for tests to
// reach out into testdata from parent packages.
func adbCopyTree(deviceCwd, subdir string) error {
	dir := ""
	for {

        // received file changes for all the files inside.
        def inputSubdirectories = (1..changesLimit).collect { inputDir.createDir("subdir${it}")}
        def inputFiles = inputSubdirectories.collect { inputDir.file("input.txt") }
        when:
        succeeds("theTask")
        inputFiles.each { it.createFile() }

        then:

        def destinationDir = spec.getDestinationDir()
        createNewFile(new File(destinationDir, "file.txt"))
        createNewFile(new File(destinationDir, "subDir/another-file.txt"))
        createNewFile(new File(destinationDir, "subDir/some-dest-file.class"))
        def annotationOutput = createNewDirectory(file("annotationOut"))
        createNewFile(new File(annotationOutput, "some-ann-file.ann"))

	// remains up to date. If so, whatever cached object it was
	// taken from can be reused.
	// The subdir gives subdirectory name where the module root is expected to be found,
	// "" for the root or "sub/dir" for a subdirectory (no trailing slash).
	CheckReuse(ctx context.Context, old *Origin, subdir string) error

	// Tags lists all tags with the given prefix.
	Tags(ctx context.Context, prefix string) (*Tags, error)

	if old == nil {
		return fmt.Errorf("missing origin")
	}
	if old.VCS != "git" || old.URL != r.remoteURL {
		return fmt.Errorf("origin moved from %v %q to %v %q", old.VCS, old.URL, "git", r.remoteURL)
	}
	if old.Subdir != subdir {
		return fmt.Errorf("origin moved from %v %q %q to %v %q %q", old.VCS, old.URL, old.Subdir, "git", r.remoteURL, subdir)
	}

		if !strings.HasPrefix(zf.Name, subdir) || strings.HasSuffix(zf.Name, "/") {
			continue
		}

		n := strings.TrimPrefix(zf.Name, subdir)
		if n == "" {
			continue
		}
		n = strings.TrimPrefix(n, "/")

		fs = append(fs, zipFile{
			name: n,
			f:    zf,
		})
		if n == "LICENSE" {
			haveLICENSE = true
		}
	}

	if !haveLICENSE && subdir != "" {

! stdout '"Reuse": true'
stdout '"URL": ".*/git/tagtests"'

# reuse with stale Dir
cp tagtestsv022.json tagtestsv022baddir.json
replace '\t\t\"Ref\":' '\t\t\"Subdir\": \"subdir\",\n\t\t\"Ref\":' tagtestsv022baddir.json
go mod download -reuse=tagtestsv022baddir.json -x -json vcs-test.golang.org/git/tagtests.git@v0.2.2
! stdout '"Reuse": true'
stdout '"URL": ".*/git/tagtests"'

	// We subtract an additional mtimeInterval
	// to account for the imprecision of our "last used" mtimes.
	cutoff := now.Add(-trimLimit - mtimeInterval)
	for i := 0; i < 256; i++ {
		subdir := filepath.Join(c.dir, fmt.Sprintf("%02x", i))
		c.trimSubdir(subdir, cutoff)
	}

	// Ignore errors from here: if we don't write the complete timestamp, the
	// cache will appear older than it is, and we'll trim it again next time.
	var b bytes.Buffer