git

type Repository interface {
	// FilesAt returns the contents of many paths as committed on branch, in one
	// operation. A path absent from the branch is absent from the result rather
	// than an error. Reading a document at a time cost a subprocess per
	// document, which was the whole of lint's running time on a repository of
	// any size.
	FilesAt(branch string, paths []string) (map[string][]byte, error)
	// Changed names which of paths differ between branch and the working tree,
	// as git itself judges it.
	//
	// git is asked rather than the bytes compared, because git applies checkout
	// filters between the blob it stores and the file it writes to disk. Under
	// end-of-line normalisation, which is the default on Windows, every frozen
	// document differed byte for byte while git reported the tree clean, so the
	// rule this tool exists to enforce failed on every document there.
	Changed(branch string, paths []string) (map[string]bool, error)
	// HasCommits reports whether the repository holds any commit at all. A
	// freshly initialised one holds none, so no document can be frozen yet and
	// the configured branch being absent is expected rather than a fault.
	HasCommits() (bool, error)
	// BranchExists reports whether branch resolves to a commit. L11 needs this
	// to tell a repository with no such branch from one where every document is
	// new, which would otherwise pass silently.
	BranchExists(branch string) (bool, error)
	// ListFiles names every path committed on branch, sorted. L11 needs it to
	// notice a frozen document deleted from the working tree, which discovery
	// cannot see.
	ListFiles(branch string) ([]string, error)
	// CurrentBranch is the checked-out branch.
	CurrentBranch() (string, error)
	// RepoRoot is the absolute path of the repository's top level.
	RepoRoot() (string, error)
	// Prefix is the path from the repository root down to the directory this
	// Repository was opened in, slash-separated, empty when they are the same.
	//
	// Asked of git rather than computed with filepath.Rel, because that
	// compares two paths obtained by different means: git reports a name as it
	// is written on disk and os.Getwd reports what the caller typed. On a
	// case-insensitive filesystem the two spellings of one directory diverge,
	// and Rel then walks out of the repository and back in. That produced a
	// generated workflow naming a path no checkout could contain, so the job
	// failed before archdoc ran.
	Prefix() (string, error)
}