type DifferentCase struct {
	Dir    string
	Query  string
	Actual string
}

type DirEntries struct {
	// contains filtered or unexported fields
}

type Entry struct {
	// contains filtered or unexported fields
}

type EntryKind uint8

const (
	DirEntry  EntryKind = 1
	FileEntry EntryKind = 2
)

type FS interface {
	// The returned map is immutable and is cached across invocations. Do not
	// mutate it.
	ReadDirectory(path string) (entries DirEntries, canonicalError error, originalError error)
	ReadFile(path string) (contents string, canonicalError error, originalError error)

	// This is a key made from the information returned by "stat". It is intended
	// to be different if the file has been edited, and to otherwise be equal if
	// the file has not been edited. It should usually work, but no guarantees.
	//
	// See https://apenwarr.ca/log/20181113 for more information about why this
	// can be broken. For example, writing to a file with mmap on WSL on Windows
	// won't change this key. Hopefully this isn't too much of an issue.
	//
	// Additional reading:
	// - https://github.com/npm/npm/pull/20027
	// - https://github.com/golang/go/commit/7dea509703eb5ad66a35628b12a678110fbb1f72
	ModKey(path string) (ModKey, error)

	// This is part of the interface because the mock interface used for tests
	// should not depend on file system behavior (i.e. different slashes for
	// Windows) while the real interface should.
	IsAbs(path string) bool
	Abs(path string) (string, bool)
	Dir(path string) string
	Base(path string) string
	Ext(path string) string
	Join(parts ...string) string
	Cwd() string
	Rel(base string, target string) (string, bool)

	// This is a set of all files used and all directories checked. The build
	// must be invalidated if any of these watched files change.
	WatchData() WatchData
	// contains filtered or unexported methods
}

type ModKey struct {
	// contains filtered or unexported fields
}

type RealFSOptions struct {
	WantWatchData bool
	AbsWorkingDir string
	DoNotCache    bool
}

type WatchData struct {
	// These functions return true if the file system entry has been modified
	Paths map[string]func() bool
}