Add generated file

This PR adds generated files under pkg/client and vendor folder.

vendor/golang.org/x/tools/godoc/vfs/emptyvfs.go

@@ -0,0 +1,89 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package vfs
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+// NewNameSpace returns a NameSpace pre-initialized with an empty
+// emulated directory mounted on the root mount point "/". This
+// allows directory traversal routines to work properly even if
+// a folder is not explicitly mounted at root by the user.
+func NewNameSpace() NameSpace {
+	ns := NameSpace{}
+	ns.Bind("/", &emptyVFS{}, "/", BindReplace)
+	return ns
+}
+
+// type emptyVFS emulates a FileSystem consisting of an empty directory
+type emptyVFS struct{}
+
+// Open implements Opener. Since emptyVFS is an empty directory, all
+// attempts to open a file should returns errors.
+func (e *emptyVFS) Open(path string) (ReadSeekCloser, error) {
+	if path == "/" {
+		return nil, fmt.Errorf("open: / is a directory")
+	}
+	return nil, os.ErrNotExist
+}
+
+// Stat returns os.FileInfo  for an empty directory if the path is
+// is root "/" or error. os.FileInfo is implemented by emptyVFS
+func (e *emptyVFS) Stat(path string) (os.FileInfo, error) {
+	if path == "/" {
+		return e, nil
+	}
+	return nil, os.ErrNotExist
+}
+
+func (e *emptyVFS) Lstat(path string) (os.FileInfo, error) {
+	return e.Stat(path)
+}
+
+// ReadDir returns an empty os.FileInfo slice for "/", else error.
+func (e *emptyVFS) ReadDir(path string) ([]os.FileInfo, error) {
+	if path == "/" {
+		return []os.FileInfo{}, nil
+	}
+	return nil, os.ErrNotExist
+}
+
+func (e *emptyVFS) String() string {
+	return "emptyVFS(/)"
+}
+
+func (e *emptyVFS) RootType(path string) RootType {
+	return ""
+}
+
+// These functions below implement os.FileInfo for the single
+// empty emulated directory.
+
+func (e *emptyVFS) Name() string {
+	return "/"
+}
+
+func (e *emptyVFS) Size() int64 {
+	return 0
+}
+
+func (e *emptyVFS) Mode() os.FileMode {
+	return os.ModeDir | os.ModePerm
+}
+
+func (e *emptyVFS) ModTime() time.Time {
+	return time.Time{}
+}
+
+func (e *emptyVFS) IsDir() bool {
+	return true
+}
+
+func (e *emptyVFS) Sys() interface{} {
+	return nil
+}

vendor/golang.org/x/tools/godoc/vfs/emptyvfs_test.go

@@ -0,0 +1,58 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package vfs_test
+
+import (
+	"testing"
+	"time"
+
+	"golang.org/x/tools/godoc/vfs"
+	"golang.org/x/tools/godoc/vfs/mapfs"
+)
+
+func TestNewNameSpace(t *testing.T) {
+
+	// We will mount this filesystem under /fs1
+	mount := mapfs.New(map[string]string{"fs1file": "abcdefgh"})
+
+	// Existing process. This should give error on Stat("/")
+	t1 := vfs.NameSpace{}
+	t1.Bind("/fs1", mount, "/", vfs.BindReplace)
+
+	// using NewNameSpace. This should work fine.
+	t2 := vfs.NewNameSpace()
+	t2.Bind("/fs1", mount, "/", vfs.BindReplace)
+
+	testcases := map[string][]bool{
+		"/":            {false, true},
+		"/fs1":         {true, true},
+		"/fs1/fs1file": {true, true},
+	}
+
+	fss := []vfs.FileSystem{t1, t2}
+
+	for j, fs := range fss {
+		for k, v := range testcases {
+			_, err := fs.Stat(k)
+			result := err == nil
+			if result != v[j] {
+				t.Errorf("fs: %d, testcase: %s, want: %v, got: %v, err: %s", j, k, v[j], result, err)
+			}
+		}
+	}
+
+	fi, err := t2.Stat("/")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if fi.Name() != "/" {
+		t.Errorf("t2.Name() : want:%s got:%s", "/", fi.Name())
+	}
+
+	if !fi.ModTime().IsZero() {
+		t.Errorf("t2.Modime() : want:%v got:%v", time.Time{}, fi.ModTime())
+	}
+}

vendor/golang.org/x/tools/godoc/vfs/gatefs/gatefs.go

@@ -0,0 +1,93 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package gatefs provides an implementation of the FileSystem
+// interface that wraps another FileSystem and limits its concurrency.
+package gatefs // import "golang.org/x/tools/godoc/vfs/gatefs"
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/tools/godoc/vfs"
+)
+
+// New returns a new FileSystem that delegates to fs.
+// If gateCh is non-nil and buffered, it's used as a gate
+// to limit concurrency on calls to fs.
+func New(fs vfs.FileSystem, gateCh chan bool) vfs.FileSystem {
+	if cap(gateCh) == 0 {
+		return fs
+	}
+	return gatefs{fs, gate(gateCh)}
+}
+
+type gate chan bool
+
+func (g gate) enter() { g <- true }
+func (g gate) leave() { <-g }
+
+type gatefs struct {
+	fs vfs.FileSystem
+	gate
+}
+
+func (fs gatefs) String() string {
+	return fmt.Sprintf("gated(%s, %d)", fs.fs.String(), cap(fs.gate))
+}
+
+func (fs gatefs) RootType(path string) vfs.RootType {
+	return fs.fs.RootType(path)
+}
+
+func (fs gatefs) Open(p string) (vfs.ReadSeekCloser, error) {
+	fs.enter()
+	defer fs.leave()
+	rsc, err := fs.fs.Open(p)
+	if err != nil {
+		return nil, err
+	}
+	return gatef{rsc, fs.gate}, nil
+}
+
+func (fs gatefs) Lstat(p string) (os.FileInfo, error) {
+	fs.enter()
+	defer fs.leave()
+	return fs.fs.Lstat(p)
+}
+
+func (fs gatefs) Stat(p string) (os.FileInfo, error) {
+	fs.enter()
+	defer fs.leave()
+	return fs.fs.Stat(p)
+}
+
+func (fs gatefs) ReadDir(p string) ([]os.FileInfo, error) {
+	fs.enter()
+	defer fs.leave()
+	return fs.fs.ReadDir(p)
+}
+
+type gatef struct {
+	rsc vfs.ReadSeekCloser
+	gate
+}
+
+func (f gatef) Read(p []byte) (n int, err error) {
+	f.enter()
+	defer f.leave()
+	return f.rsc.Read(p)
+}
+
+func (f gatef) Seek(offset int64, whence int) (ret int64, err error) {
+	f.enter()
+	defer f.leave()
+	return f.rsc.Seek(offset, whence)
+}
+
+func (f gatef) Close() error {
+	f.enter()
+	defer f.leave()
+	return f.rsc.Close()
+}

vendor/golang.org/x/tools/godoc/vfs/gatefs/gatefs_test.go

@@ -0,0 +1,39 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gatefs_test
+
+import (
+	"os"
+	"runtime"
+	"testing"
+
+	"golang.org/x/tools/godoc/vfs"
+	"golang.org/x/tools/godoc/vfs/gatefs"
+)
+
+func TestRootType(t *testing.T) {
+	goPath := os.Getenv("GOPATH")
+	var expectedType vfs.RootType
+	if goPath == "" {
+		expectedType = ""
+	} else {
+		expectedType = vfs.RootTypeGoPath
+	}
+	tests := []struct {
+		path   string
+		fsType vfs.RootType
+	}{
+		{runtime.GOROOT(), vfs.RootTypeGoRoot},
+		{goPath, expectedType},
+		{"/tmp/", ""},
+	}
+
+	for _, item := range tests {
+		fs := gatefs.New(vfs.OS(item.path), make(chan bool, 1))
+		if fs.RootType("path") != item.fsType {
+			t.Errorf("unexpected fsType. Expected- %v, Got- %v", item.fsType, fs.RootType("path"))
+		}
+	}
+}

vendor/golang.org/x/tools/godoc/vfs/httpfs/httpfs.go

@@ -0,0 +1,94 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package httpfs implements http.FileSystem using a godoc vfs.FileSystem.
+package httpfs // import "golang.org/x/tools/godoc/vfs/httpfs"
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+
+	"golang.org/x/tools/godoc/vfs"
+)
+
+func New(fs vfs.FileSystem) http.FileSystem {
+	return &httpFS{fs}
+}
+
+type httpFS struct {
+	fs vfs.FileSystem
+}
+
+func (h *httpFS) Open(name string) (http.File, error) {
+	fi, err := h.fs.Stat(name)
+	if err != nil {
+		return nil, err
+	}
+	if fi.IsDir() {
+		return &httpDir{h.fs, name, nil}, nil
+	}
+	f, err := h.fs.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return &httpFile{h.fs, f, name}, nil
+}
+
+// httpDir implements http.File for a directory in a FileSystem.
+type httpDir struct {
+	fs      vfs.FileSystem
+	name    string
+	pending []os.FileInfo
+}
+
+func (h *httpDir) Close() error               { return nil }
+func (h *httpDir) Stat() (os.FileInfo, error) { return h.fs.Stat(h.name) }
+func (h *httpDir) Read([]byte) (int, error) {
+	return 0, fmt.Errorf("cannot Read from directory %s", h.name)
+}
+
+func (h *httpDir) Seek(offset int64, whence int) (int64, error) {
+	if offset == 0 && whence == 0 {
+		h.pending = nil
+		return 0, nil
+	}
+	return 0, fmt.Errorf("unsupported Seek in directory %s", h.name)
+}
+
+func (h *httpDir) Readdir(count int) ([]os.FileInfo, error) {
+	if h.pending == nil {
+		d, err := h.fs.ReadDir(h.name)
+		if err != nil {
+			return nil, err
+		}
+		if d == nil {
+			d = []os.FileInfo{} // not nil
+		}
+		h.pending = d
+	}
+
+	if len(h.pending) == 0 && count > 0 {
+		return nil, io.EOF
+	}
+	if count <= 0 || count > len(h.pending) {
+		count = len(h.pending)
+	}
+	d := h.pending[:count]
+	h.pending = h.pending[count:]
+	return d, nil
+}
+
+// httpFile implements http.File for a file (not directory) in a FileSystem.
+type httpFile struct {
+	fs vfs.FileSystem
+	vfs.ReadSeekCloser
+	name string
+}
+
+func (h *httpFile) Stat() (os.FileInfo, error) { return h.fs.Stat(h.name) }
+func (h *httpFile) Readdir(int) ([]os.FileInfo, error) {
+	return nil, fmt.Errorf("cannot Readdir from file %s", h.name)
+}

vendor/golang.org/x/tools/godoc/vfs/mapfs/mapfs.go

@@ -0,0 +1,156 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package mapfs file provides an implementation of the FileSystem
+// interface based on the contents of a map[string]string.
+package mapfs // import "golang.org/x/tools/godoc/vfs/mapfs"
+
+import (
+	"io"
+	"os"
+	pathpkg "path"
+	"sort"
+	"strings"
+	"time"
+
+	"golang.org/x/tools/godoc/vfs"
+)
+
+// New returns a new FileSystem from the provided map.
+// Map keys should be forward slash-separated pathnames
+// and not contain a leading slash.
+func New(m map[string]string) vfs.FileSystem {
+	return mapFS(m)
+}
+
+// mapFS is the map based implementation of FileSystem
+type mapFS map[string]string
+
+func (fs mapFS) String() string { return "mapfs" }
+
+func (fs mapFS) RootType(p string) vfs.RootType {
+	return ""
+}
+
+func (fs mapFS) Close() error { return nil }
+
+func filename(p string) string {
+	return strings.TrimPrefix(p, "/")
+}
+
+func (fs mapFS) Open(p string) (vfs.ReadSeekCloser, error) {
+	b, ok := fs[filename(p)]
+	if !ok {
+		return nil, os.ErrNotExist
+	}
+	return nopCloser{strings.NewReader(b)}, nil
+}
+
+func fileInfo(name, contents string) os.FileInfo {
+	return mapFI{name: pathpkg.Base(name), size: len(contents)}
+}
+
+func dirInfo(name string) os.FileInfo {
+	return mapFI{name: pathpkg.Base(name), dir: true}
+}
+
+func (fs mapFS) Lstat(p string) (os.FileInfo, error) {
+	b, ok := fs[filename(p)]
+	if ok {
+		return fileInfo(p, b), nil
+	}
+	ents, _ := fs.ReadDir(p)
+	if len(ents) > 0 {
+		return dirInfo(p), nil
+	}
+	return nil, os.ErrNotExist
+}
+
+func (fs mapFS) Stat(p string) (os.FileInfo, error) {
+	return fs.Lstat(p)
+}
+
+// slashdir returns path.Dir(p), but special-cases paths not beginning
+// with a slash to be in the root.
+func slashdir(p string) string {
+	d := pathpkg.Dir(p)
+	if d == "." {
+		return "/"
+	}
+	if strings.HasPrefix(p, "/") {
+		return d
+	}
+	return "/" + d
+}
+
+func (fs mapFS) ReadDir(p string) ([]os.FileInfo, error) {
+	p = pathpkg.Clean(p)
+	var ents []string
+	fim := make(map[string]os.FileInfo) // base -> fi
+	for fn, b := range fs {
+		dir := slashdir(fn)
+		isFile := true
+		var lastBase string
+		for {
+			if dir == p {
+				base := lastBase
+				if isFile {
+					base = pathpkg.Base(fn)
+				}
+				if fim[base] == nil {
+					var fi os.FileInfo
+					if isFile {
+						fi = fileInfo(fn, b)
+					} else {
+						fi = dirInfo(base)
+					}
+					ents = append(ents, base)
+					fim[base] = fi
+				}
+			}
+			if dir == "/" {
+				break
+			} else {
+				isFile = false
+				lastBase = pathpkg.Base(dir)
+				dir = pathpkg.Dir(dir)
+			}
+		}
+	}
+	if len(ents) == 0 {
+		return nil, os.ErrNotExist
+	}
+
+	sort.Strings(ents)
+	var list []os.FileInfo
+	for _, dir := range ents {
+		list = append(list, fim[dir])
+	}
+	return list, nil
+}
+
+// mapFI is the map-based implementation of FileInfo.
+type mapFI struct {
+	name string
+	size int
+	dir  bool
+}
+
+func (fi mapFI) IsDir() bool        { return fi.dir }
+func (fi mapFI) ModTime() time.Time { return time.Time{} }
+func (fi mapFI) Mode() os.FileMode {
+	if fi.IsDir() {
+		return 0755 | os.ModeDir
+	}
+	return 0444
+}
+func (fi mapFI) Name() string     { return pathpkg.Base(fi.name) }
+func (fi mapFI) Size() int64      { return int64(fi.size) }
+func (fi mapFI) Sys() interface{} { return nil }
+
+type nopCloser struct {
+	io.ReadSeeker
+}
+
+func (nc nopCloser) Close() error { return nil }

vendor/golang.org/x/tools/godoc/vfs/mapfs/mapfs_test.go

@@ -0,0 +1,111 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mapfs
+
+import (
+	"io/ioutil"
+	"os"
+	"reflect"
+	"testing"
+)
+
+func TestOpenRoot(t *testing.T) {
+	fs := New(map[string]string{
+		"foo/bar/three.txt": "a",
+		"foo/bar.txt":       "b",
+		"top.txt":           "c",
+		"other-top.txt":     "d",
+	})
+	tests := []struct {
+		path string
+		want string
+	}{
+		{"/foo/bar/three.txt", "a"},
+		{"foo/bar/three.txt", "a"},
+		{"foo/bar.txt", "b"},
+		{"top.txt", "c"},
+		{"/top.txt", "c"},
+		{"other-top.txt", "d"},
+		{"/other-top.txt", "d"},
+	}
+	for _, tt := range tests {
+		rsc, err := fs.Open(tt.path)
+		if err != nil {
+			t.Errorf("Open(%q) = %v", tt.path, err)
+			continue
+		}
+		slurp, err := ioutil.ReadAll(rsc)
+		if err != nil {
+			t.Error(err)
+		}
+		if string(slurp) != tt.want {
+			t.Errorf("Read(%q) = %q; want %q", tt.path, tt.want, slurp)
+		}
+		rsc.Close()
+	}
+
+	_, err := fs.Open("/xxxx")
+	if !os.IsNotExist(err) {
+		t.Errorf("ReadDir /xxxx = %v; want os.IsNotExist error", err)
+	}
+}
+
+func TestReaddir(t *testing.T) {
+	fs := New(map[string]string{
+		"foo/bar/three.txt": "333",
+		"foo/bar.txt":       "22",
+		"top.txt":           "top.txt file",
+		"other-top.txt":     "other-top.txt file",
+	})
+	tests := []struct {
+		dir  string
+		want []os.FileInfo
+	}{
+		{
+			dir: "/",
+			want: []os.FileInfo{
+				mapFI{name: "foo", dir: true},
+				mapFI{name: "other-top.txt", size: len("other-top.txt file")},
+				mapFI{name: "top.txt", size: len("top.txt file")},
+			},
+		},
+		{
+			dir: "/foo",
+			want: []os.FileInfo{
+				mapFI{name: "bar", dir: true},
+				mapFI{name: "bar.txt", size: 2},
+			},
+		},
+		{
+			dir: "/foo/",
+			want: []os.FileInfo{
+				mapFI{name: "bar", dir: true},
+				mapFI{name: "bar.txt", size: 2},
+			},
+		},
+		{
+			dir: "/foo/bar",
+			want: []os.FileInfo{
+				mapFI{name: "three.txt", size: 3},
+			},
+		},
+	}
+	for _, tt := range tests {
+		fis, err := fs.ReadDir(tt.dir)
+		if err != nil {
+			t.Errorf("ReadDir(%q) = %v", tt.dir, err)
+			continue
+		}
+		if !reflect.DeepEqual(fis, tt.want) {
+			t.Errorf("ReadDir(%q) = %#v; want %#v", tt.dir, fis, tt.want)
+			continue
+		}
+	}
+
+	_, err := fs.ReadDir("/xxxx")
+	if !os.IsNotExist(err) {
+		t.Errorf("ReadDir /xxxx = %v; want os.IsNotExist error", err)
+	}
+}

vendor/golang.org/x/tools/godoc/vfs/namespace.go

@@ -0,0 +1,403 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package vfs
+
+import (
+	"fmt"
+	"io"
+	"os"
+	pathpkg "path"
+	"sort"
+	"strings"
+	"time"
+)
+
+// Setting debugNS = true will enable debugging prints about
+// name space translations.
+const debugNS = false
+
+// A NameSpace is a file system made up of other file systems
+// mounted at specific locations in the name space.
+//
+// The representation is a map from mount point locations
+// to the list of file systems mounted at that location.  A traditional
+// Unix mount table would use a single file system per mount point,
+// but we want to be able to mount multiple file systems on a single
+// mount point and have the system behave as if the union of those
+// file systems were present at the mount point.
+// For example, if the OS file system has a Go installation in
+// c:\Go and additional Go path trees in  d:\Work1 and d:\Work2, then
+// this name space creates the view we want for the godoc server:
+//
+//	NameSpace{
+//		"/": {
+//			{old: "/", fs: OS(`c:\Go`), new: "/"},
+//		},
+//		"/src/pkg": {
+//			{old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
+//			{old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
+//			{old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
+//		},
+//	}
+//
+// This is created by executing:
+//
+//	ns := NameSpace{}
+//	ns.Bind("/", OS(`c:\Go`), "/", BindReplace)
+//	ns.Bind("/src/pkg", OS(`d:\Work1`), "/src", BindAfter)
+//	ns.Bind("/src/pkg", OS(`d:\Work2`), "/src", BindAfter)
+//
+// A particular mount point entry is a triple (old, fs, new), meaning that to
+// operate on a path beginning with old, replace that prefix (old) with new
+// and then pass that path to the FileSystem implementation fs.
+//
+// If you do not explicitly mount a FileSystem at the root mountpoint "/" of the
+// NameSpace like above, Stat("/") will return a "not found" error which could
+// break typical directory traversal routines. In such cases, use NewNameSpace()
+// to get a NameSpace pre-initialized with an emulated empty directory at root.
+//
+// Given this name space, a ReadDir of /src/pkg/code will check each prefix
+// of the path for a mount point (first /src/pkg/code, then /src/pkg, then /src,
+// then /), stopping when it finds one.  For the above example, /src/pkg/code
+// will find the mount point at /src/pkg:
+//
+//	{old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
+//	{old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
+//	{old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
+//
+// ReadDir will when execute these three calls and merge the results:
+//
+//	OS(`c:\Go`).ReadDir("/src/pkg/code")
+//	OS(`d:\Work1').ReadDir("/src/code")
+//	OS(`d:\Work2').ReadDir("/src/code")
+//
+// Note that the "/src/pkg" in "/src/pkg/code" has been replaced by
+// just "/src" in the final two calls.
+//
+// OS is itself an implementation of a file system: it implements
+// OS(`c:\Go`).ReadDir("/src/pkg/code") as ioutil.ReadDir(`c:\Go\src\pkg\code`).
+//
+// Because the new path is evaluated by fs (here OS(root)), another way
+// to read the mount table is to mentally combine fs+new, so that this table:
+//
+//	{old: "/src/pkg", fs: OS(`c:\Go`), new: "/src/pkg"},
+//	{old: "/src/pkg", fs: OS(`d:\Work1`), new: "/src"},
+//	{old: "/src/pkg", fs: OS(`d:\Work2`), new: "/src"},
+//
+// reads as:
+//
+//	"/src/pkg" -> c:\Go\src\pkg
+//	"/src/pkg" -> d:\Work1\src
+//	"/src/pkg" -> d:\Work2\src
+//
+// An invariant (a redundancy) of the name space representation is that
+// ns[mtpt][i].old is always equal to mtpt (in the example, ns["/src/pkg"]'s
+// mount table entries always have old == "/src/pkg").  The 'old' field is
+// useful to callers, because they receive just a []mountedFS and not any
+// other indication of which mount point was found.
+//
+type NameSpace map[string][]mountedFS
+
+// A mountedFS handles requests for path by replacing
+// a prefix 'old' with 'new' and then calling the fs methods.
+type mountedFS struct {
+	old string
+	fs  FileSystem
+	new string
+}
+
+// hasPathPrefix returns true if x == y or x == y + "/" + more
+func hasPathPrefix(x, y string) bool {
+	return x == y || strings.HasPrefix(x, y) && (strings.HasSuffix(y, "/") || strings.HasPrefix(x[len(y):], "/"))
+}
+
+// translate translates path for use in m, replacing old with new.
+//
+// mountedFS{"/src/pkg", fs, "/src"}.translate("/src/pkg/code") == "/src/code".
+func (m mountedFS) translate(path string) string {
+	path = pathpkg.Clean("/" + path)
+	if !hasPathPrefix(path, m.old) {
+		panic("translate " + path + " but old=" + m.old)
+	}
+	return pathpkg.Join(m.new, path[len(m.old):])
+}
+
+func (NameSpace) String() string {
+	return "ns"
+}
+
+// Fprint writes a text representation of the name space to w.
+func (ns NameSpace) Fprint(w io.Writer) {
+	fmt.Fprint(w, "name space {\n")
+	var all []string
+	for mtpt := range ns {
+		all = append(all, mtpt)
+	}
+	sort.Strings(all)
+	for _, mtpt := range all {
+		fmt.Fprintf(w, "\t%s:\n", mtpt)
+		for _, m := range ns[mtpt] {
+			fmt.Fprintf(w, "\t\t%s %s\n", m.fs, m.new)
+		}
+	}
+	fmt.Fprint(w, "}\n")
+}
+
+// clean returns a cleaned, rooted path for evaluation.
+// It canonicalizes the path so that we can use string operations
+// to analyze it.
+func (NameSpace) clean(path string) string {
+	return pathpkg.Clean("/" + path)
+}
+
+type BindMode int
+
+const (
+	BindReplace BindMode = iota
+	BindBefore
+	BindAfter
+)
+
+// Bind causes references to old to redirect to the path new in newfs.
+// If mode is BindReplace, old redirections are discarded.
+// If mode is BindBefore, this redirection takes priority over existing ones,
+// but earlier ones are still consulted for paths that do not exist in newfs.
+// If mode is BindAfter, this redirection happens only after existing ones
+// have been tried and failed.
+func (ns NameSpace) Bind(old string, newfs FileSystem, new string, mode BindMode) {
+	old = ns.clean(old)
+	new = ns.clean(new)
+	m := mountedFS{old, newfs, new}
+	var mtpt []mountedFS
+	switch mode {
+	case BindReplace:
+		mtpt = append(mtpt, m)
+	case BindAfter:
+		mtpt = append(mtpt, ns.resolve(old)...)
+		mtpt = append(mtpt, m)
+	case BindBefore:
+		mtpt = append(mtpt, m)
+		mtpt = append(mtpt, ns.resolve(old)...)
+	}
+
+	// Extend m.old, m.new in inherited mount point entries.
+	for i := range mtpt {
+		m := &mtpt[i]
+		if m.old != old {
+			if !hasPathPrefix(old, m.old) {
+				// This should not happen.  If it does, panic so
+				// that we can see the call trace that led to it.
+				panic(fmt.Sprintf("invalid Bind: old=%q m={%q, %s, %q}", old, m.old, m.fs.String(), m.new))
+			}
+			suffix := old[len(m.old):]
+			m.old = pathpkg.Join(m.old, suffix)
+			m.new = pathpkg.Join(m.new, suffix)
+		}
+	}
+
+	ns[old] = mtpt
+}
+
+// resolve resolves a path to the list of mountedFS to use for path.
+func (ns NameSpace) resolve(path string) []mountedFS {
+	path = ns.clean(path)
+	for {
+		if m := ns[path]; m != nil {
+			if debugNS {
+				fmt.Printf("resolve %s: %v\n", path, m)
+			}
+			return m
+		}
+		if path == "/" {
+			break
+		}
+		path = pathpkg.Dir(path)
+	}
+	return nil
+}
+
+// Open implements the FileSystem Open method.
+func (ns NameSpace) Open(path string) (ReadSeekCloser, error) {
+	var err error
+	for _, m := range ns.resolve(path) {
+		if debugNS {
+			fmt.Printf("tx %s: %v\n", path, m.translate(path))
+		}
+		tp := m.translate(path)
+		r, err1 := m.fs.Open(tp)
+		if err1 == nil {
+			return r, nil
+		}
+		// IsNotExist errors in overlay FSes can mask real errors in
+		// the underlying FS, so ignore them if there is another error.
+		if err == nil || os.IsNotExist(err) {
+			err = err1
+		}
+	}
+	if err == nil {
+		err = &os.PathError{Op: "open", Path: path, Err: os.ErrNotExist}
+	}
+	return nil, err
+}
+
+// stat implements the FileSystem Stat and Lstat methods.
+func (ns NameSpace) stat(path string, f func(FileSystem, string) (os.FileInfo, error)) (os.FileInfo, error) {
+	var err error
+	for _, m := range ns.resolve(path) {
+		fi, err1 := f(m.fs, m.translate(path))
+		if err1 == nil {
+			return fi, nil
+		}
+		if err == nil {
+			err = err1
+		}
+	}
+	if err == nil {
+		err = &os.PathError{Op: "stat", Path: path, Err: os.ErrNotExist}
+	}
+	return nil, err
+}
+
+func (ns NameSpace) Stat(path string) (os.FileInfo, error) {
+	return ns.stat(path, FileSystem.Stat)
+}
+
+func (ns NameSpace) Lstat(path string) (os.FileInfo, error) {
+	return ns.stat(path, FileSystem.Lstat)
+}
+
+// dirInfo is a trivial implementation of os.FileInfo for a directory.
+type dirInfo string
+
+func (d dirInfo) Name() string       { return string(d) }
+func (d dirInfo) Size() int64        { return 0 }
+func (d dirInfo) Mode() os.FileMode  { return os.ModeDir | 0555 }
+func (d dirInfo) ModTime() time.Time { return startTime }
+func (d dirInfo) IsDir() bool        { return true }
+func (d dirInfo) Sys() interface{}   { return nil }
+
+var startTime = time.Now()
+
+// ReadDir implements the FileSystem ReadDir method.  It's where most of the magic is.
+// (The rest is in resolve.)
+//
+// Logically, ReadDir must return the union of all the directories that are named
+// by path.  In order to avoid misinterpreting Go packages, of all the directories
+// that contain Go source code, we only include the files from the first,
+// but we include subdirectories from all.
+//
+// ReadDir must also return directory entries needed to reach mount points.
+// If the name space looks like the example in the type NameSpace comment,
+// but c:\Go does not have a src/pkg subdirectory, we still want to be able
+// to find that subdirectory, because we've mounted d:\Work1 and d:\Work2
+// there.  So if we don't see "src" in the directory listing for c:\Go, we add an
+// entry for it before returning.
+//
+func (ns NameSpace) ReadDir(path string) ([]os.FileInfo, error) {
+	path = ns.clean(path)
+
+	var (
+		haveGo   = false
+		haveName = map[string]bool{}
+		all      []os.FileInfo
+		err      error
+		first    []os.FileInfo
+	)
+
+	for _, m := range ns.resolve(path) {
+		dir, err1 := m.fs.ReadDir(m.translate(path))
+		if err1 != nil {
+			if err == nil {
+				err = err1
+			}
+			continue
+		}
+
+		if dir == nil {
+			dir = []os.FileInfo{}
+		}
+
+		if first == nil {
+			first = dir
+		}
+
+		// If we don't yet have Go files in 'all' and this directory
+		// has some, add all the files from this directory.
+		// Otherwise, only add subdirectories.
+		useFiles := false
+		if !haveGo {
+			for _, d := range dir {
+				if strings.HasSuffix(d.Name(), ".go") {
+					useFiles = true
+					haveGo = true
+					break
+				}
+			}
+		}
+
+		for _, d := range dir {
+			name := d.Name()
+			if (d.IsDir() || useFiles) && !haveName[name] {
+				haveName[name] = true
+				all = append(all, d)
+			}
+		}
+	}
+
+	// We didn't find any directories containing Go files.
+	// If some directory returned successfully, use that.
+	if !haveGo {
+		for _, d := range first {
+			if !haveName[d.Name()] {
+				haveName[d.Name()] = true
+				all = append(all, d)
+			}
+		}
+	}
+
+	// Built union.  Add any missing directories needed to reach mount points.
+	for old := range ns {
+		if hasPathPrefix(old, path) && old != path {
+			// Find next element after path in old.
+			elem := old[len(path):]
+			elem = strings.TrimPrefix(elem, "/")
+			if i := strings.Index(elem, "/"); i >= 0 {
+				elem = elem[:i]
+			}
+			if !haveName[elem] {
+				haveName[elem] = true
+				all = append(all, dirInfo(elem))
+			}
+		}
+	}
+
+	if len(all) == 0 {
+		return nil, err
+	}
+
+	sort.Sort(byName(all))
+	return all, nil
+}
+
+// RootType returns the RootType for the given path in the namespace.
+func (ns NameSpace) RootType(path string) RootType {
+	// We resolve the given path to a list of mountedFS and then return
+	// the root type for the filesystem which contains the path.
+	for _, m := range ns.resolve(path) {
+		_, err := m.fs.ReadDir(m.translate(path))
+		// Found a match, return the filesystem's root type
+		if err == nil {
+			return m.fs.RootType(path)
+		}
+	}
+	return ""
+}
+
+// byName implements sort.Interface.
+type byName []os.FileInfo
+
+func (f byName) Len() int           { return len(f) }
+func (f byName) Less(i, j int) bool { return f[i].Name() < f[j].Name() }
+func (f byName) Swap(i, j int)      { f[i], f[j] = f[j], f[i] }

vendor/golang.org/x/tools/godoc/vfs/os.go

@@ -0,0 +1,97 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package vfs
+
+import (
+	"fmt"
+	"go/build"
+	"io/ioutil"
+	"os"
+	pathpkg "path"
+	"path/filepath"
+	"runtime"
+)
+
+// OS returns an implementation of FileSystem reading from the
+// tree rooted at root.  Recording a root is convenient everywhere
+// but necessary on Windows, because the slash-separated path
+// passed to Open has no way to specify a drive letter.  Using a root
+// lets code refer to OS(`c:\`), OS(`d:\`) and so on.
+func OS(root string) FileSystem {
+	var t RootType
+	switch {
+	case root == runtime.GOROOT():
+		t = RootTypeGoRoot
+	case isGoPath(root):
+		t = RootTypeGoPath
+	}
+	return osFS{rootPath: root, rootType: t}
+}
+
+type osFS struct {
+	rootPath string
+	rootType RootType
+}
+
+func isGoPath(path string) bool {
+	for _, bp := range filepath.SplitList(build.Default.GOPATH) {
+		for _, gp := range filepath.SplitList(path) {
+			if bp == gp {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (root osFS) String() string { return "os(" + root.rootPath + ")" }
+
+// RootType returns the root type for the filesystem.
+//
+// Note that we ignore the path argument because roottype is a property of
+// this filesystem. But for other filesystems, the roottype might need to be
+// dynamically deduced at call time.
+func (root osFS) RootType(path string) RootType {
+	return root.rootType
+}
+
+func (root osFS) resolve(path string) string {
+	// Clean the path so that it cannot possibly begin with ../.
+	// If it did, the result of filepath.Join would be outside the
+	// tree rooted at root.  We probably won't ever see a path
+	// with .. in it, but be safe anyway.
+	path = pathpkg.Clean("/" + path)
+
+	return filepath.Join(root.rootPath, path)
+}
+
+func (root osFS) Open(path string) (ReadSeekCloser, error) {
+	f, err := os.Open(root.resolve(path))
+	if err != nil {
+		return nil, err
+	}
+	fi, err := f.Stat()
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	if fi.IsDir() {
+		f.Close()
+		return nil, fmt.Errorf("Open: %s is a directory", path)
+	}
+	return f, nil
+}
+
+func (root osFS) Lstat(path string) (os.FileInfo, error) {
+	return os.Lstat(root.resolve(path))
+}
+
+func (root osFS) Stat(path string) (os.FileInfo, error) {
+	return os.Stat(root.resolve(path))
+}
+
+func (root osFS) ReadDir(path string) ([]os.FileInfo, error) {
+	return ioutil.ReadDir(root.resolve(path)) // is sorted
+}

vendor/golang.org/x/tools/godoc/vfs/os_test.go

@@ -0,0 +1,38 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package vfs_test
+
+import (
+	"os"
+	"runtime"
+	"testing"
+
+	"golang.org/x/tools/godoc/vfs"
+)
+
+func TestRootType(t *testing.T) {
+	goPath := os.Getenv("GOPATH")
+	var expectedType vfs.RootType
+	if goPath == "" {
+		expectedType = ""
+	} else {
+		expectedType = vfs.RootTypeGoPath
+	}
+	tests := []struct {
+		path   string
+		fsType vfs.RootType
+	}{
+		{runtime.GOROOT(), vfs.RootTypeGoRoot},
+		{goPath, expectedType},
+		{"/tmp/", ""},
+	}
+
+	for _, item := range tests {
+		fs := vfs.OS(item.path)
+		if fs.RootType("path") != item.fsType {
+			t.Errorf("unexpected fsType. Expected- %v, Got- %v", item.fsType, fs.RootType("path"))
+		}
+	}
+}

vendor/golang.org/x/tools/godoc/vfs/vfs.go

@@ -0,0 +1,58 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package vfs defines types for abstract file system access and provides an
+// implementation accessing the file system of the underlying OS.
+package vfs // import "golang.org/x/tools/godoc/vfs"
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+)
+
+// RootType indicates the type of files contained within a directory.
+//
+// It is used to indicate whether a directory is the root
+// of a GOROOT, a GOPATH, or neither.
+// An empty string represents the case when a directory is neither.
+type RootType string
+
+const (
+	RootTypeGoRoot RootType = "GOROOT"
+	RootTypeGoPath RootType = "GOPATH"
+)
+
+// The FileSystem interface specifies the methods godoc is using
+// to access the file system for which it serves documentation.
+type FileSystem interface {
+	Opener
+	Lstat(path string) (os.FileInfo, error)
+	Stat(path string) (os.FileInfo, error)
+	ReadDir(path string) ([]os.FileInfo, error)
+	RootType(path string) RootType
+	String() string
+}
+
+// Opener is a minimal virtual filesystem that can only open regular files.
+type Opener interface {
+	Open(name string) (ReadSeekCloser, error)
+}
+
+// A ReadSeekCloser can Read, Seek, and Close.
+type ReadSeekCloser interface {
+	io.Reader
+	io.Seeker
+	io.Closer
+}
+
+// ReadFile reads the file named by path from fs and returns the contents.
+func ReadFile(fs Opener, path string) ([]byte, error) {
+	rc, err := fs.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer rc.Close()
+	return ioutil.ReadAll(rc)
+}

vendor/golang.org/x/tools/godoc/vfs/zipfs/zipfs.go

@@ -0,0 +1,287 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package zipfs file provides an implementation of the FileSystem
+// interface based on the contents of a .zip file.
+//
+// Assumptions:
+//
+// - The file paths stored in the zip file must use a slash ('/') as path
+//   separator; and they must be relative (i.e., they must not start with
+//   a '/' - this is usually the case if the file was created w/o special
+//   options).
+// - The zip file system treats the file paths found in the zip internally
+//   like absolute paths w/o a leading '/'; i.e., the paths are considered
+//   relative to the root of the file system.
+// - All path arguments to file system methods must be absolute paths.
+package zipfs // import "golang.org/x/tools/godoc/vfs/zipfs"
+
+import (
+	"archive/zip"
+	"fmt"
+	"go/build"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"runtime"
+	"sort"
+	"strings"
+	"time"
+
+	"golang.org/x/tools/godoc/vfs"
+)
+
+// zipFI is the zip-file based implementation of FileInfo
+type zipFI struct {
+	name string    // directory-local name
+	file *zip.File // nil for a directory
+}
+
+func (fi zipFI) Name() string {
+	return fi.name
+}
+
+func (fi zipFI) Size() int64 {
+	if f := fi.file; f != nil {
+		return int64(f.UncompressedSize)
+	}
+	return 0 // directory
+}
+
+func (fi zipFI) ModTime() time.Time {
+	if f := fi.file; f != nil {
+		return f.ModTime()
+	}
+	return time.Time{} // directory has no modified time entry
+}
+
+func (fi zipFI) Mode() os.FileMode {
+	if fi.file == nil {
+		// Unix directories typically are executable, hence 555.
+		return os.ModeDir | 0555
+	}
+	return 0444
+}
+
+func (fi zipFI) IsDir() bool {
+	return fi.file == nil
+}
+
+func (fi zipFI) Sys() interface{} {
+	return nil
+}
+
+// zipFS is the zip-file based implementation of FileSystem
+type zipFS struct {
+	*zip.ReadCloser
+	list zipList
+	name string
+}
+
+func (fs *zipFS) String() string {
+	return "zip(" + fs.name + ")"
+}
+
+func (fs *zipFS) RootType(abspath string) vfs.RootType {
+	var t vfs.RootType
+	switch {
+	case abspath == runtime.GOROOT():
+		t = vfs.RootTypeGoRoot
+	case isGoPath(abspath):
+		t = vfs.RootTypeGoPath
+	}
+	return t
+}
+
+func isGoPath(path string) bool {
+	for _, p := range filepath.SplitList(build.Default.GOPATH) {
+		if p == path {
+			return true
+		}
+	}
+	return false
+}
+
+func (fs *zipFS) Close() error {
+	fs.list = nil
+	return fs.ReadCloser.Close()
+}
+
+func zipPath(name string) (string, error) {
+	name = path.Clean(name)
+	if !path.IsAbs(name) {
+		return "", fmt.Errorf("stat: not an absolute path: %s", name)
+	}
+	return name[1:], nil // strip leading '/'
+}
+
+func isRoot(abspath string) bool {
+	return path.Clean(abspath) == "/"
+}
+
+func (fs *zipFS) stat(abspath string) (int, zipFI, error) {
+	if isRoot(abspath) {
+		return 0, zipFI{
+			name: "",
+			file: nil,
+		}, nil
+	}
+	zippath, err := zipPath(abspath)
+	if err != nil {
+		return 0, zipFI{}, err
+	}
+	i, exact := fs.list.lookup(zippath)
+	if i < 0 {
+		// zippath has leading '/' stripped - print it explicitly
+		return -1, zipFI{}, &os.PathError{Path: "/" + zippath, Err: os.ErrNotExist}
+	}
+	_, name := path.Split(zippath)
+	var file *zip.File
+	if exact {
+		file = fs.list[i] // exact match found - must be a file
+	}
+	return i, zipFI{name, file}, nil
+}
+
+func (fs *zipFS) Open(abspath string) (vfs.ReadSeekCloser, error) {
+	_, fi, err := fs.stat(abspath)
+	if err != nil {
+		return nil, err
+	}
+	if fi.IsDir() {
+		return nil, fmt.Errorf("Open: %s is a directory", abspath)
+	}
+	r, err := fi.file.Open()
+	if err != nil {
+		return nil, err
+	}
+	return &zipSeek{fi.file, r}, nil
+}
+
+type zipSeek struct {
+	file *zip.File
+	io.ReadCloser
+}
+
+func (f *zipSeek) Seek(offset int64, whence int) (int64, error) {
+	if whence == 0 && offset == 0 {
+		r, err := f.file.Open()
+		if err != nil {
+			return 0, err
+		}
+		f.Close()
+		f.ReadCloser = r
+		return 0, nil
+	}
+	return 0, fmt.Errorf("unsupported Seek in %s", f.file.Name)
+}
+
+func (fs *zipFS) Lstat(abspath string) (os.FileInfo, error) {
+	_, fi, err := fs.stat(abspath)
+	return fi, err
+}
+
+func (fs *zipFS) Stat(abspath string) (os.FileInfo, error) {
+	_, fi, err := fs.stat(abspath)
+	return fi, err
+}
+
+func (fs *zipFS) ReadDir(abspath string) ([]os.FileInfo, error) {
+	i, fi, err := fs.stat(abspath)
+	if err != nil {
+		return nil, err
+	}
+	if !fi.IsDir() {
+		return nil, fmt.Errorf("ReadDir: %s is not a directory", abspath)
+	}
+
+	var list []os.FileInfo
+
+	// make dirname the prefix that file names must start with to be considered
+	// in this directory. we must special case the root directory because, per
+	// the spec of this package, zip file entries MUST NOT start with /, so we
+	// should not append /, as we would in every other case.
+	var dirname string
+	if isRoot(abspath) {
+		dirname = ""
+	} else {
+		zippath, err := zipPath(abspath)
+		if err != nil {
+			return nil, err
+		}
+		dirname = zippath + "/"
+	}
+	prevname := ""
+	for _, e := range fs.list[i:] {
+		if !strings.HasPrefix(e.Name, dirname) {
+			break // not in the same directory anymore
+		}
+		name := e.Name[len(dirname):] // local name
+		file := e
+		if i := strings.IndexRune(name, '/'); i >= 0 {
+			// We infer directories from files in subdirectories.
+			// If we have x/y, return a directory entry for x.
+			name = name[0:i] // keep local directory name only
+			file = nil
+		}
+		// If we have x/y and x/z, don't return two directory entries for x.
+		// TODO(gri): It should be possible to do this more efficiently
+		// by determining the (fs.list) range of local directory entries
+		// (via two binary searches).
+		if name != prevname {
+			list = append(list, zipFI{name, file})
+			prevname = name
+		}
+	}
+
+	return list, nil
+}
+
+func New(rc *zip.ReadCloser, name string) vfs.FileSystem {
+	list := make(zipList, len(rc.File))
+	copy(list, rc.File) // sort a copy of rc.File
+	sort.Sort(list)
+	return &zipFS{rc, list, name}
+}
+
+type zipList []*zip.File
+
+// zipList implements sort.Interface
+func (z zipList) Len() int           { return len(z) }
+func (z zipList) Less(i, j int) bool { return z[i].Name < z[j].Name }
+func (z zipList) Swap(i, j int)      { z[i], z[j] = z[j], z[i] }
+
+// lookup returns the smallest index of an entry with an exact match
+// for name, or an inexact match starting with name/. If there is no
+// such entry, the result is -1, false.
+func (z zipList) lookup(name string) (index int, exact bool) {
+	// look for exact match first (name comes before name/ in z)
+	i := sort.Search(len(z), func(i int) bool {
+		return name <= z[i].Name
+	})
+	if i >= len(z) {
+		return -1, false
+	}
+	// 0 <= i < len(z)
+	if z[i].Name == name {
+		return i, true
+	}
+
+	// look for inexact match (must be in z[i:], if present)
+	z = z[i:]
+	name += "/"
+	j := sort.Search(len(z), func(i int) bool {
+		return name <= z[i].Name
+	})
+	if j >= len(z) {
+		return -1, false
+	}
+	// 0 <= j < len(z)
+	if strings.HasPrefix(z[j].Name, name) {
+		return i + j, false
+	}
+
+	return -1, false
+}

vendor/golang.org/x/tools/godoc/vfs/zipfs/zipfs_test.go

@@ -0,0 +1,189 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.package zipfs
+package zipfs
+
+import (
+	"archive/zip"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"reflect"
+	"testing"
+
+	"golang.org/x/tools/godoc/vfs"
+)
+
+var (
+
+	// files to use to build zip used by zipfs in testing; maps path : contents
+	files = map[string]string{"foo": "foo", "bar/baz": "baz", "a/b/c": "c"}
+
+	// expected info for each entry in a file system described by files
+	tests = []struct {
+		Path      string
+		IsDir     bool
+		IsRegular bool
+		Name      string
+		Contents  string
+		Files     map[string]bool
+	}{
+		{"/", true, false, "", "", map[string]bool{"foo": true, "bar": true, "a": true}},
+		{"//", true, false, "", "", map[string]bool{"foo": true, "bar": true, "a": true}},
+		{"/foo", false, true, "foo", "foo", nil},
+		{"/foo/", false, true, "foo", "foo", nil},
+		{"/foo//", false, true, "foo", "foo", nil},
+		{"/bar", true, false, "bar", "", map[string]bool{"baz": true}},
+		{"/bar/", true, false, "bar", "", map[string]bool{"baz": true}},
+		{"/bar/baz", false, true, "baz", "baz", nil},
+		{"//bar//baz", false, true, "baz", "baz", nil},
+		{"/a/b", true, false, "b", "", map[string]bool{"c": true}},
+	}
+
+	// to be initialized in setup()
+	fs        vfs.FileSystem
+	statFuncs []statFunc
+)
+
+type statFunc struct {
+	Name string
+	Func func(string) (os.FileInfo, error)
+}
+
+func TestMain(t *testing.M) {
+	if err := setup(); err != nil {
+		fmt.Fprintf(os.Stderr, "Error setting up zipfs testing state: %v.\n", err)
+		os.Exit(1)
+	}
+	os.Exit(t.Run())
+}
+
+// setups state each of the tests uses
+func setup() error {
+	// create zipfs
+	b := new(bytes.Buffer)
+	zw := zip.NewWriter(b)
+	for file, contents := range files {
+		w, err := zw.Create(file)
+		if err != nil {
+			return err
+		}
+		_, err = io.WriteString(w, contents)
+		if err != nil {
+			return err
+		}
+	}
+	zw.Close()
+	zr, err := zip.NewReader(bytes.NewReader(b.Bytes()), int64(b.Len()))
+	if err != nil {
+		return err
+	}
+	rc := &zip.ReadCloser{
+		Reader: *zr,
+	}
+	fs = New(rc, "foo")
+
+	// pull out different stat functions
+	statFuncs = []statFunc{
+		{"Stat", fs.Stat},
+		{"Lstat", fs.Lstat},
+	}
+
+	return nil
+}
+
+func TestZipFSReadDir(t *testing.T) {
+	for _, test := range tests {
+		if test.IsDir {
+			infos, err := fs.ReadDir(test.Path)
+			if err != nil {
+				t.Errorf("Failed to read directory %v\n", test.Path)
+				continue
+			}
+			got := make(map[string]bool)
+			for _, info := range infos {
+				got[info.Name()] = true
+			}
+			if want := test.Files; !reflect.DeepEqual(got, want) {
+				t.Errorf("ReadDir %v got %v\nwanted %v\n", test.Path, got, want)
+			}
+		}
+	}
+}
+
+func TestZipFSStatFuncs(t *testing.T) {
+	for _, test := range tests {
+		for _, statFunc := range statFuncs {
+
+			// test can stat
+			info, err := statFunc.Func(test.Path)
+			if err != nil {
+				t.Errorf("Unexpected error using %v for %v: %v\n", statFunc.Name, test.Path, err)
+				continue
+			}
+
+			// test info.Name()
+			if got, want := info.Name(), test.Name; got != want {
+				t.Errorf("Using %v for %v info.Name() got %v wanted %v\n", statFunc.Name, test.Path, got, want)
+			}
+			// test info.IsDir()
+			if got, want := info.IsDir(), test.IsDir; got != want {
+				t.Errorf("Using %v for %v info.IsDir() got %v wanted %v\n", statFunc.Name, test.Path, got, want)
+			}
+			// test info.Mode().IsDir()
+			if got, want := info.Mode().IsDir(), test.IsDir; got != want {
+				t.Errorf("Using %v for %v info.Mode().IsDir() got %v wanted %v\n", statFunc.Name, test.Path, got, want)
+			}
+			// test info.Mode().IsRegular()
+			if got, want := info.Mode().IsRegular(), test.IsRegular; got != want {
+				t.Errorf("Using %v for %v info.Mode().IsRegular() got %v wanted %v\n", statFunc.Name, test.Path, got, want)
+			}
+			// test info.Size()
+			if test.IsRegular {
+				if got, want := info.Size(), int64(len(test.Contents)); got != want {
+					t.Errorf("Using %v for %v inf.Size() got %v wanted %v", statFunc.Name, test.Path, got, want)
+				}
+			}
+		}
+	}
+}
+
+func TestZipFSNotExist(t *testing.T) {
+	_, err := fs.Open("/does-not-exist")
+	if err == nil {
+		t.Fatalf("Expected an error.\n")
+	}
+	if !os.IsNotExist(err) {
+		t.Errorf("Expected an error satisfying os.IsNotExist: %v\n", err)
+	}
+}
+
+func TestZipFSOpenSeek(t *testing.T) {
+	for _, test := range tests {
+		if test.IsRegular {
+
+			// test Open()
+			f, err := fs.Open(test.Path)
+			if err != nil {
+				t.Error(err)
+				return
+			}
+			defer f.Close()
+
+			// test Seek() multiple times
+			for i := 0; i < 3; i++ {
+				all, err := ioutil.ReadAll(f)
+				if err != nil {
+					t.Error(err)
+					return
+				}
+				if got, want := string(all), test.Contents; got != want {
+					t.Errorf("File contents for %v got %v wanted %v\n", test.Path, got, want)
+				}
+				f.Seek(0, 0)
+			}
+		}
+	}
+}