sap-jenkins-library/pkg/mock/fileUtils.go

// +build !release

package mock

import (
	"fmt"
	"github.com/bmatcuk/doublestar"
	"os"
	"path/filepath"
	"sort"
	"strings"
)

var dirContent []byte

type fileProperties struct {
	content *[]byte
	mode    *os.FileMode
}

//FilesMock implements the functions from piperutils.Files with an in-memory file system.
type FilesMock struct {
	files        map[string]*fileProperties
	writtenFiles []string
	removedFiles []string
	currentDir   string
	Separator    string
}

func (f *FilesMock) init() {
	if f.files == nil {
		f.files = map[string]*fileProperties{}
	}
	if f.Separator == "" {
		f.Separator = string(os.PathSeparator)
	}
}

func (f *FilesMock) toAbsPath(path string) string {
	if !strings.HasPrefix(path, f.Separator) {
		path = f.Separator + filepath.Join(f.currentDir, path)
	}
	return path
}

// AddFile establishes the existence of a virtual file. The file is
// added with mode 644
func (f *FilesMock) AddFile(path string, contents []byte) {
	f.AddFileWithMode(path, contents, 0644)
}

// AddFileWithMode establishes the existence of a virtual file.
func (f *FilesMock) AddFileWithMode(path string, contents []byte, mode os.FileMode) {
	f.associateContent(path, &contents, &mode)
}

// AddDir establishes the existence of a virtual directory. The directory
// is add with default mode 755
func (f *FilesMock) AddDir(path string) {
	f.AddDirWithMode(path, 0755)
}

// AddDirWithMode establishes the existence of a virtual directory.
func (f *FilesMock) AddDirWithMode(path string, mode os.FileMode) {
	f.associateContent(path, &dirContent, &mode)
}

func (f *FilesMock) associateContent(path string, content *[]byte, mode *os.FileMode) {
	f.init()
	path = strings.ReplaceAll(path, "/", f.Separator)
	path = strings.ReplaceAll(path, "\\", f.Separator)
	path = f.toAbsPath(path)
	if _, ok := f.files[path]; !ok {
		f.files[path] = &fileProperties{}
	}
	props := f.files[path]
	props.content = content
	props.mode = mode
}

// HasFile returns true if the virtual file system contains an entry for the given path.
func (f *FilesMock) HasFile(path string) bool {
	_, exists := f.files[f.toAbsPath(path)]
	return exists
}

// HasRemovedFile returns true if the virtual file system at one point contained an entry for the given path,
// and it was removed via FileRemove().
func (f *FilesMock) HasRemovedFile(path string) bool {
	return contains(f.removedFiles, f.toAbsPath(path))
}

// HasWrittenFile returns true if the virtual file system at one point contained an entry for the given path,
// and it was written via FileWrite().
func (f *FilesMock) HasWrittenFile(path string) bool {
	return contains(f.writtenFiles, f.toAbsPath(path))
}

func contains(collection []string, name string) bool {
	for _, entry := range collection {
		if entry == name {
			return true
		}
	}
	return false
}

// FileExists returns true if file content has been associated with the given path, false otherwise.
// Only relative paths are supported.
func (f *FilesMock) FileExists(path string) (bool, error) {
	if f.files == nil {
		return false, nil
	}
	props, exists := f.files[f.toAbsPath(path)]
	if !exists {
		return false, nil
	}
	return props.content != &dirContent, nil
}

// DirExists returns true, if the given path is a previously added directory, or a parent directory for any of the
// previously added files.
func (f *FilesMock) DirExists(path string) (bool, error) {
	path = f.toAbsPath(path)
	for entry, props := range f.files {
		var dirComponents []string
		if props.content == &dirContent {
			dirComponents = strings.Split(entry, f.Separator)
		} else {
			dirComponents = strings.Split(filepath.Dir(entry), f.Separator)
		}
		if len(dirComponents) > 0 {
			dir := ""
			for i, component := range dirComponents {
				if i == 0 {
					dir = component
				} else {
					dir = dir + f.Separator + component
				}
				if dir == path {
					return true, nil
				}
			}
		}
	}
	return false, nil
}

// Copy checks if content has been associated with the given src path, and if so copies it under the given path dst.
func (f *FilesMock) Copy(src, dst string) (int64, error) {
	f.init()
	props, exists := f.files[f.toAbsPath(src)]
	if !exists || props.content == &dirContent {
		return 0, fmt.Errorf("cannot copy '%s': %w", src, os.ErrNotExist)
	}
	f.AddFileWithMode(dst, *props.content, *props.mode)
	return int64(len(*props.content)), nil
}

// FileRead returns the content previously associated with the given path via AddFile(), or an error if no
// content has been associated.
func (f *FilesMock) FileRead(path string) ([]byte, error) {
	f.init()
	props, exists := f.files[f.toAbsPath(path)]
	if !exists {
		return nil, fmt.Errorf("could not read '%s'", path)
	}
	// check if trying to open a directory for reading
	if props.content == &dirContent {
		return nil, fmt.Errorf("could not read '%s': %w", path, os.ErrInvalid)
	}
	return *props.content, nil
}

// FileWrite just forwards to AddFile(), i.e. the content is associated with the given path.
func (f *FilesMock) FileWrite(path string, content []byte, mode os.FileMode) error {
	f.init()
	// NOTE: FilesMock could be extended to have a set of paths for which FileWrite should fail.
	// This is why AddFile() exists separately, to differentiate the notion of setting up the mocking
	// versus implementing the methods from Files.
	f.writtenFiles = append(f.writtenFiles, f.toAbsPath(path))
	f.AddFileWithMode(path, content, mode)
	return nil
}

// FileRemove deletes the association of the given path with any content and records the removal of the file.
// If the path has not been registered before, it returns an error.
func (f *FilesMock) FileRemove(path string) error {
	if f.files == nil {
		return fmt.Errorf("the file '%s' does not exist: %w", path, os.ErrNotExist)
	}
	absPath := f.toAbsPath(path)
	_, exists := f.files[absPath]
	if !exists {
		return fmt.Errorf("the file '%s' does not exist: %w", path, os.ErrNotExist)
	}
	delete(f.files, absPath)
	f.removedFiles = append(f.removedFiles, absPath)
	return nil
}

// MkdirAll creates a directory in the in-memory file system, so that this path is established to exist.
func (f *FilesMock) MkdirAll(path string, mode os.FileMode) error {
	// NOTE: FilesMock could be extended to have a set of paths for which MkdirAll should fail.
	// This is why AddDir() exists separately, to differentiate the notion of setting up the mocking
	// versus implementing the methods from Files.
	f.AddDirWithMode(path, mode)
	return nil
}

// Glob returns an array of path strings which match the given glob-pattern. Double star matching is supported.
func (f *FilesMock) Glob(pattern string) ([]string, error) {
	var matches []string
	if f.files == nil {
		return matches, nil
	}
	for path := range f.files {
		path = strings.TrimLeft(path, f.Separator)
		matched, _ := doublestar.PathMatch(pattern, path)
		if matched {
			matches = append(matches, path)
		}
	}
	// The order in f.files is not deterministic, this would result in flaky tests.
	sort.Strings(matches)
	return matches, nil
}

// Getwd returns the rooted current virtual working directory
func (f *FilesMock) Getwd() (string, error) {
	f.init()
	return f.toAbsPath(""), nil
}

// Chdir changes virtually in to the given directory.
// The directory needs to exist according to the files and directories via AddFile() and AddDirectory().
// The implementation does not support relative path components such as "..".
func (f *FilesMock) Chdir(path string) error {
	if path == "." || path == "."+f.Separator {
		return nil
	}

	path = f.toAbsPath(path)

	exists, _ := f.DirExists(path)
	if !exists {
		return fmt.Errorf("failed to change current directory into '%s': %w", path, os.ErrNotExist)
	}

	f.currentDir = strings.TrimLeft(path, f.Separator)
	return nil
}