populate/e2e_test.go - gitfs - Git at Google

 // Copyright 2016 Google Inc. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //    http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package populate

 import (
 	"fmt"
 	"io/ioutil"
 	"log"
 	"net"
 	"os"
 	"path/filepath"
 	"reflect"
 	"testing"

 	"gopkg.in/src-d/go-git.v4/plumbing"

 	"github.com/google/slothfs/cache"
 	"github.com/google/slothfs/fs"
 	"github.com/google/slothfs/gitiles"
 	"github.com/google/slothfs/manifest"
 	"github.com/hanwen/go-fuse/fuse"
 	"github.com/hanwen/go-fuse/fuse/nodefs"
 )

 // a bunch of random sha1s.
 var ids = []string{
 	"f065f1478dc8bfebdc59f20fb2fc1f8da4d7c334",
 	"ae6d11c113a0a20be662df287899046f74092abe",
 	"9200e4a97b6e051dd56d3de5378febae40a367e9",
 	"7ba00d0407ed4467c874ab45bb47fcb82fe63fac",
 }

 func getID(s string) *plumbing.Hash {
 	h, err := parseID(s)
 	if err != nil {
 		log.Panic(err)
 	}
 	return h
 }

 func newInt(i int) *int {
 	return &i
 }

 func newString(s string) *string {
 	return &s
 }

 func abortListener(l net.Listener) {
 	for {
 		conn, err := l.Accept()
 		if err != nil {
 			break
 		}
 		conn.Close()
 	}
 }

 type fixture struct {
 	dir          string
 	cache        *cache.Cache
 	fsServer     *fuse.Server
 	abortGitiles net.Listener
 }

 func (f *fixture) Cleanup() {
 	if f.abortGitiles != nil {
 		f.abortGitiles.Close()
 	}
 	if f.fsServer != nil {
 		if err := f.fsServer.Unmount(); err != nil {
 			return
 		}
 	}
 	os.RemoveAll(f.dir)
 }

 func (f *fixture) addWorkspace(name string, mf *manifest.Manifest) error {
 	bytes1, err := mf.MarshalXML()
 	if err != nil {
 		return err
 	}

 	dir := f.dir

 	if err := ioutil.WriteFile(filepath.Join(dir, name+".xml"), bytes1, 0644); err != nil {
 		return err
 	}
 	if err := os.Symlink(filepath.Join(dir, name+".xml"), filepath.Join(dir, "mnt", "config", name)); err != nil {
 		return err
 	}
 	return nil
 }

 func newFixture() (*fixture, error) {
 	dir, err := ioutil.TempDir("", "")
 	if err != nil {
 		return nil, err
 	}

 	fix := fixture{dir: dir}
 	for _, d := range []string{"mnt", "ws", "cache"} {
 		if err := os.MkdirAll(filepath.Join(dir, d), 0755); err != nil {
 			return nil, err
 		}
 	}

 	fix.cache, err = cache.NewCache(filepath.Join(dir, "cache"), cache.Options{})
 	if err != nil {
 		return nil, err
 	}

 	// Setup a fake gitiles; make sure we never talk to it.
 	fix.abortGitiles, err = net.Listen("tcp", ":0")
 	if err != nil {
 		return nil, err
 	}
 	go abortListener(fix.abortGitiles)

 	service, err := gitiles.NewService(gitiles.Options{
 		Address: fmt.Sprintf("http://%s/", fix.abortGitiles.Addr()),
 	})
 	if err != nil {
 		log.Printf("NewService: %v", err)
 	}

 	opts := fs.MultiManifestFSOptions{}

 	root := fs.NewMultiManifestFS(service, fix.cache, opts)
 	fuseOpts := nodefs.NewOptions()
 	fix.fsServer, _, err = nodefs.MountRoot(filepath.Join(dir, "mnt"), root, fuseOpts)
 	if err != nil {
 		return nil, err
 	}

 	go fix.fsServer.Serve()

 	return &fix, nil
 }

 func TestCopyEntries(t *testing.T) {
 	fixture, err := newFixture()
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer fixture.Cleanup()

 	// We avoid talking to gitiles by inserting entries into the
 	// cache manually.
 	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
 		ID: ids[0],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "a",
 				Type: "blob",
 				ID:   ids[1],
 				Size: newInt(42),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}

 	if err := fixture.addWorkspace("m", &manifest.Manifest{
 		Project: []manifest.Project{{
 			Name:     "platform/project",
 			Path:     newString("p"),
 			Revision: ids[0],
 			Copyfile: []manifest.Copyfile{
 				{Src: "a", Dest: "bla"},
 			},
 		}}}); err != nil {
 		t.Fatalf("addWorkspace: %v", err)
 	}

 	ws := filepath.Join(fixture.dir, "ws")
 	roRoot := filepath.Join(fixture.dir, "mnt", "m")
 	if _, _, err := Checkout(roRoot, ws); err != nil {
 		t.Fatalf("Checkout: %v", err)
 	}

 	if dest, err := os.Readlink(filepath.Join(ws, "bla")); err != nil {
 		t.Fatal(err)
 	} else if want := filepath.Join(roRoot, "bla"); dest != want {
 		t.Fatalf("Readlink(ws/sub): got %q, want %q", dest, want)
 	}

 }

 func TestBrokenWorkspaceLink(t *testing.T) {
 	fixture, err := newFixture()
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer fixture.Cleanup()

 	// We avoid talking to gitiles by inserting entries into the
 	// cache manually.
 	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
 		ID: ids[0],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "a",
 				Type: "blob",
 				ID:   ids[1],
 				Size: newInt(42),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}

 	for i := 0; i <= 1; i++ {
 		if err := fixture.addWorkspace(fmt.Sprintf("m%d", i), &manifest.Manifest{
 			Project: []manifest.Project{{
 				Name:     "platform/project",
 				Path:     newString("p"),
 				Revision: ids[0],
 			}}}); err != nil {
 			t.Fatalf("addWorkspace(%d): %v", i, err)
 		}
 	}

 	ws := filepath.Join(fixture.dir, "ws")
 	m0 := filepath.Join(fixture.dir, "mnt", "m0")
 	if _, _, err := Checkout(m0, ws); err != nil {
 		t.Fatalf("Checkout(m0): %v", err)
 	}

 	if err := os.Remove(filepath.Join(fixture.dir, "mnt", "config", "m0")); err != nil {
 		log.Fatalf("Remove: %v", err)
 	}

 	m1 := filepath.Join(fixture.dir, "mnt", "m1")
 	if _, changed, err := Checkout(m1, ws); err != nil {
 		t.Fatalf("Checkout(m1): %v", err)
 	} else if len(changed) > 0 {
 		t.Errorf("Got changed files %v relative to broken link", changed)
 	}
 }

 func TestFUSESymlink(t *testing.T) {
 	fixture, err := newFixture()
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer fixture.Cleanup()

 	// We avoid talking to gitiles by inserting entries into the
 	// cache manually.
 	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
 		ID: ids[0],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "a",
 				Type: "blob",
 				ID:   ids[1],
 				Size: newInt(42),
 			},
 			{
 				Mode:   0100644,
 				Name:   "link",
 				Type:   "blob",
 				ID:     ids[2],
 				Size:   newInt(1),
 				Target: newString("non-existent"),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}

 	// We avoid talking to gitiles by inserting entries into the
 	// cache manually.
 	if err := fixture.cache.Tree.Add(gitID(ids[1]), &gitiles.Tree{
 		ID: ids[1],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "a",
 				Type: "blob",
 				ID:   ids[1],
 				Size: newInt(42),
 			},
 			{
 				Mode:   0100644,
 				Name:   "link",
 				Type:   "blob",
 				ID:     ids[3],
 				Size:   newInt(1),
 				Target: newString("a"),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}

 	for i := 0; i <= 1; i++ {
 		if err := fixture.addWorkspace(fmt.Sprintf("m%d", i), &manifest.Manifest{
 			Project: []manifest.Project{{
 				Name:     "platform/project",
 				Path:     newString("p"),
 				Revision: ids[i],
 			}}}); err != nil {
 			t.Fatalf("addWorkspace(%d): %v", i, err)
 		}
 	}

 	ws := filepath.Join(fixture.dir, "ws")
 	m0 := filepath.Join(fixture.dir, "mnt", "m0")
 	added, changed, err := Checkout(m0, ws)
 	if err != nil {
 		t.Fatalf("Checkout m0: %v", err)
 	}
 	if len(changed) > 0 {
 		t.Errorf("got changed files %v on fresh checkout", changed)
 	}
 	if want := []string{filepath.Join(m0, "p/a"), filepath.Join(m0, "p/link")}; !reflect.DeepEqual(added, want) {
 		t.Errorf("got added %v want %v on fresh checkout", added, want)
 	}

 	m1 := filepath.Join(fixture.dir, "mnt", "m1")
 	added, changed, err = Checkout(m1, ws)
 	if len(added) > 0 {
 		t.Errorf("got added files %v on sync", added)
 	}
 	if want := []string{filepath.Join(m1, "p/link")}; !reflect.DeepEqual(changed, want) {
 		t.Errorf("got changed files %v, want %v", changed, want)
 	}
 }

 func TestBasic(t *testing.T) {
 	fixture, err := newFixture()
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer fixture.Cleanup()
 	dir := fixture.dir

 	// We avoid talking to gitiles by inserting entries into the
 	// cache manually.
 	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
 		ID: ids[0],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "a",
 				Type: "blob",
 				ID:   ids[1],
 				Size: newInt(1),
 			},
 			{
 				Mode: 0100644,
 				Name: "b/c",
 				Type: "blob",
 				ID:   ids[2],
 				Size: newInt(1),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}
 	if err := fixture.cache.Tree.Add(gitID(ids[1]), &gitiles.Tree{
 		ID: ids[1],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "a",
 				Type: "blob",
 				ID:   ids[2],
 				Size: newInt(1),
 			},
 			{
 				Mode: 0100644,
 				Name: "b/c",
 				Type: "blob",
 				ID:   ids[2],
 				Size: newInt(1),
 			},
 			{
 				Mode: 0100644,
 				Name: "new",
 				Type: "blob",
 				ID:   ids[3],
 				Size: newInt(1),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}

 	if err := fixture.cache.Tree.Add(gitID(ids[2]), &gitiles.Tree{
 		ID: ids[2],
 		Entries: []gitiles.TreeEntry{
 			{
 				Mode: 0100644,
 				Name: "d",
 				Type: "blob",
 				ID:   ids[3],
 				Size: newInt(1),
 			},
 		},
 	}); err != nil {
 		t.Fatal(err)
 	}

 	if err := fixture.addWorkspace("m1", &manifest.Manifest{
 		Project: []manifest.Project{{
 			Name:     "platform/project",
 			Path:     newString("project"),
 			Revision: ids[0],
 		}}}); err != nil {
 		t.Fatalf("addWorkspace(m1): %v", err)
 	}

 	if err := fixture.addWorkspace("m2", &manifest.Manifest{
 		Project: []manifest.Project{
 			{
 				Name:     "platform/project",
 				Path:     newString("project"),
 				Revision: ids[1],
 			}, {
 				Name:     "platform/sub",
 				Path:     newString("sub"),
 				Revision: ids[2],
 			}},
 	}); err != nil {
 		t.Fatalf("addWorkspace(m2): %v", err)
 	}

 	testFile := filepath.Join(dir, "mnt", "m1", "project", "b/c")
 	if fi, err := os.Lstat(testFile); err != nil {
 		t.Fatalf("Lstat(%s): %v", testFile, err)
 	} else if fi.Size() != 1 {
 		t.Fatalf("%s has size %d", testFile, fi.Size())
 	}

 	ws := filepath.Join(dir, "ws")

 	if _, _, err := Checkout(filepath.Join(dir, "mnt", "m1"), ws); err != nil {
 		t.Fatal("Checkout m1:", err)
 	}

 	if dest, err := os.Readlink(filepath.Join(ws, "project")); err != nil {
 		t.Fatal(err)
 	} else if want := filepath.Join(dir, "mnt", "m1", "project"); dest != want {
 		t.Fatalf("got %q, want %q", dest, want)
 	}

 	// Make sure we detect changed files. We have to be careful in
 	// the test setup that no blobs are shared with newly
 	// appearing files, or they'll be touched for being new files.

 	added, changed, err := Checkout(filepath.Join(dir, "mnt", "m2"), ws)
 	if err != nil {
 		t.Fatal(err)
 	}

 	if want := []string{filepath.Join(dir, "mnt", "m2", "project/a")}; !reflect.DeepEqual(changed, want) {
 		t.Errorf("got changed %v, want %v", changed, want)
 	}

 	if want := []string{
 		filepath.Join(dir, "mnt", "m2", "project/new"),
 		filepath.Join(dir, "mnt", "m2", "sub/d"),
 	}; !reflect.DeepEqual(added, want) {
 		t.Errorf("got added %v, want %v", added, want)
 	}

 	if dest, err := os.Readlink(filepath.Join(ws, "sub")); err != nil {
 		t.Fatal(err)
 	} else if want := filepath.Join(dir, "mnt", "m2", "sub"); dest != want {
 		t.Fatalf("Readlink(ws/sub): got %q, want %q", dest, want)
 	}
 }
	// Copyright 2016 Google Inc. All rights reserved.
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package populate

	import (
	"fmt"
	"io/ioutil"
	"log"
	"net"
	"os"
	"path/filepath"
	"reflect"
	"testing"

	"gopkg.in/src-d/go-git.v4/plumbing"

	"github.com/google/slothfs/cache"
	"github.com/google/slothfs/fs"
	"github.com/google/slothfs/gitiles"
	"github.com/google/slothfs/manifest"
	"github.com/hanwen/go-fuse/fuse"
	"github.com/hanwen/go-fuse/fuse/nodefs"
	)

	// a bunch of random sha1s.
	var ids = []string{
	"f065f1478dc8bfebdc59f20fb2fc1f8da4d7c334",
	"ae6d11c113a0a20be662df287899046f74092abe",
	"9200e4a97b6e051dd56d3de5378febae40a367e9",
	"7ba00d0407ed4467c874ab45bb47fcb82fe63fac",
	}

	func getID(s string) *plumbing.Hash {
	h, err := parseID(s)
	if err != nil {
	log.Panic(err)
	}
	return h
	}

	func newInt(i int) *int {
	return &i
	}

	func newString(s string) *string {
	return &s
	}

	func abortListener(l net.Listener) {
	for {
	conn, err := l.Accept()
	if err != nil {
	break
	}
	conn.Close()
	}
	}

	type fixture struct {
	dir string
	cache *cache.Cache
	fsServer *fuse.Server
	abortGitiles net.Listener
	}

	func (f *fixture) Cleanup() {
	if f.abortGitiles != nil {
	f.abortGitiles.Close()
	}
	if f.fsServer != nil {
	if err := f.fsServer.Unmount(); err != nil {
	return
	}
	}
	os.RemoveAll(f.dir)
	}

	func (f fixture) addWorkspace(name string, mf manifest.Manifest) error {
	bytes1, err := mf.MarshalXML()
	if err != nil {
	return err
	}

	dir := f.dir

	if err := ioutil.WriteFile(filepath.Join(dir, name+".xml"), bytes1, 0644); err != nil {
	return err
	}
	if err := os.Symlink(filepath.Join(dir, name+".xml"), filepath.Join(dir, "mnt", "config", name)); err != nil {
	return err
	}
	return nil
	}

	func newFixture() (*fixture, error) {
	dir, err := ioutil.TempDir("", "")
	if err != nil {
	return nil, err
	}

	fix := fixture{dir: dir}
	for _, d := range []string{"mnt", "ws", "cache"} {
	if err := os.MkdirAll(filepath.Join(dir, d), 0755); err != nil {
	return nil, err
	}
	}

	fix.cache, err = cache.NewCache(filepath.Join(dir, "cache"), cache.Options{})
	if err != nil {
	return nil, err
	}

	// Setup a fake gitiles; make sure we never talk to it.
	fix.abortGitiles, err = net.Listen("tcp", ":0")
	if err != nil {
	return nil, err
	}
	go abortListener(fix.abortGitiles)

	service, err := gitiles.NewService(gitiles.Options{
	Address: fmt.Sprintf("http://%s/", fix.abortGitiles.Addr()),
	})
	if err != nil {
	log.Printf("NewService: %v", err)
	}

	opts := fs.MultiManifestFSOptions{}

	root := fs.NewMultiManifestFS(service, fix.cache, opts)
	fuseOpts := nodefs.NewOptions()
	fix.fsServer, _, err = nodefs.MountRoot(filepath.Join(dir, "mnt"), root, fuseOpts)
	if err != nil {
	return nil, err
	}

	go fix.fsServer.Serve()

	return &fix, nil
	}

	func TestCopyEntries(t *testing.T) {
	fixture, err := newFixture()
	if err != nil {
	t.Fatal(err)
	}
	defer fixture.Cleanup()

	// We avoid talking to gitiles by inserting entries into the
	// cache manually.
	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
	ID: ids[0],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "a",
	Type: "blob",
	ID: ids[1],
	Size: newInt(42),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}

	if err := fixture.addWorkspace("m", &manifest.Manifest{
	Project: []manifest.Project{{
	Name: "platform/project",
	Path: newString("p"),
	Revision: ids[0],
	Copyfile: []manifest.Copyfile{
	{Src: "a", Dest: "bla"},
	},
	}}}); err != nil {
	t.Fatalf("addWorkspace: %v", err)
	}

	ws := filepath.Join(fixture.dir, "ws")
	roRoot := filepath.Join(fixture.dir, "mnt", "m")
	if _, _, err := Checkout(roRoot, ws); err != nil {
	t.Fatalf("Checkout: %v", err)
	}

	if dest, err := os.Readlink(filepath.Join(ws, "bla")); err != nil {
	t.Fatal(err)
	} else if want := filepath.Join(roRoot, "bla"); dest != want {
	t.Fatalf("Readlink(ws/sub): got %q, want %q", dest, want)
	}

	}

	func TestBrokenWorkspaceLink(t *testing.T) {
	fixture, err := newFixture()
	if err != nil {
	t.Fatal(err)
	}
	defer fixture.Cleanup()

	// We avoid talking to gitiles by inserting entries into the
	// cache manually.
	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
	ID: ids[0],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "a",
	Type: "blob",
	ID: ids[1],
	Size: newInt(42),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}

	for i := 0; i <= 1; i++ {
	if err := fixture.addWorkspace(fmt.Sprintf("m%d", i), &manifest.Manifest{
	Project: []manifest.Project{{
	Name: "platform/project",
	Path: newString("p"),
	Revision: ids[0],
	}}}); err != nil {
	t.Fatalf("addWorkspace(%d): %v", i, err)
	}
	}

	ws := filepath.Join(fixture.dir, "ws")
	m0 := filepath.Join(fixture.dir, "mnt", "m0")
	if _, _, err := Checkout(m0, ws); err != nil {
	t.Fatalf("Checkout(m0): %v", err)
	}

	if err := os.Remove(filepath.Join(fixture.dir, "mnt", "config", "m0")); err != nil {
	log.Fatalf("Remove: %v", err)
	}

	m1 := filepath.Join(fixture.dir, "mnt", "m1")
	if _, changed, err := Checkout(m1, ws); err != nil {
	t.Fatalf("Checkout(m1): %v", err)
	} else if len(changed) > 0 {
	t.Errorf("Got changed files %v relative to broken link", changed)
	}
	}

	func TestFUSESymlink(t *testing.T) {
	fixture, err := newFixture()
	if err != nil {
	t.Fatal(err)
	}
	defer fixture.Cleanup()

	// We avoid talking to gitiles by inserting entries into the
	// cache manually.
	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
	ID: ids[0],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "a",
	Type: "blob",
	ID: ids[1],
	Size: newInt(42),
	},
	{
	Mode: 0100644,
	Name: "link",
	Type: "blob",
	ID: ids[2],
	Size: newInt(1),
	Target: newString("non-existent"),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}

	// We avoid talking to gitiles by inserting entries into the
	// cache manually.
	if err := fixture.cache.Tree.Add(gitID(ids[1]), &gitiles.Tree{
	ID: ids[1],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "a",
	Type: "blob",
	ID: ids[1],
	Size: newInt(42),
	},
	{
	Mode: 0100644,
	Name: "link",
	Type: "blob",
	ID: ids[3],
	Size: newInt(1),
	Target: newString("a"),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}

	for i := 0; i <= 1; i++ {
	if err := fixture.addWorkspace(fmt.Sprintf("m%d", i), &manifest.Manifest{
	Project: []manifest.Project{{
	Name: "platform/project",
	Path: newString("p"),
	Revision: ids[i],
	}}}); err != nil {
	t.Fatalf("addWorkspace(%d): %v", i, err)
	}
	}

	ws := filepath.Join(fixture.dir, "ws")
	m0 := filepath.Join(fixture.dir, "mnt", "m0")
	added, changed, err := Checkout(m0, ws)
	if err != nil {
	t.Fatalf("Checkout m0: %v", err)
	}
	if len(changed) > 0 {
	t.Errorf("got changed files %v on fresh checkout", changed)
	}
	if want := []string{filepath.Join(m0, "p/a"), filepath.Join(m0, "p/link")}; !reflect.DeepEqual(added, want) {
	t.Errorf("got added %v want %v on fresh checkout", added, want)
	}

	m1 := filepath.Join(fixture.dir, "mnt", "m1")
	added, changed, err = Checkout(m1, ws)
	if len(added) > 0 {
	t.Errorf("got added files %v on sync", added)
	}
	if want := []string{filepath.Join(m1, "p/link")}; !reflect.DeepEqual(changed, want) {
	t.Errorf("got changed files %v, want %v", changed, want)
	}
	}

	func TestBasic(t *testing.T) {
	fixture, err := newFixture()
	if err != nil {
	t.Fatal(err)
	}
	defer fixture.Cleanup()
	dir := fixture.dir

	// We avoid talking to gitiles by inserting entries into the
	// cache manually.
	if err := fixture.cache.Tree.Add(gitID(ids[0]), &gitiles.Tree{
	ID: ids[0],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "a",
	Type: "blob",
	ID: ids[1],
	Size: newInt(1),
	},
	{
	Mode: 0100644,
	Name: "b/c",
	Type: "blob",
	ID: ids[2],
	Size: newInt(1),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}
	if err := fixture.cache.Tree.Add(gitID(ids[1]), &gitiles.Tree{
	ID: ids[1],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "a",
	Type: "blob",
	ID: ids[2],
	Size: newInt(1),
	},
	{
	Mode: 0100644,
	Name: "b/c",
	Type: "blob",
	ID: ids[2],
	Size: newInt(1),
	},
	{
	Mode: 0100644,
	Name: "new",
	Type: "blob",
	ID: ids[3],
	Size: newInt(1),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}

	if err := fixture.cache.Tree.Add(gitID(ids[2]), &gitiles.Tree{
	ID: ids[2],
	Entries: []gitiles.TreeEntry{
	{
	Mode: 0100644,
	Name: "d",
	Type: "blob",
	ID: ids[3],
	Size: newInt(1),
	},
	},
	}); err != nil {
	t.Fatal(err)
	}

	if err := fixture.addWorkspace("m1", &manifest.Manifest{
	Project: []manifest.Project{{
	Name: "platform/project",
	Path: newString("project"),
	Revision: ids[0],
	}}}); err != nil {
	t.Fatalf("addWorkspace(m1): %v", err)
	}

	if err := fixture.addWorkspace("m2", &manifest.Manifest{
	Project: []manifest.Project{
	{
	Name: "platform/project",
	Path: newString("project"),
	Revision: ids[1],
	}, {
	Name: "platform/sub",
	Path: newString("sub"),
	Revision: ids[2],
	}},
	}); err != nil {
	t.Fatalf("addWorkspace(m2): %v", err)
	}

	testFile := filepath.Join(dir, "mnt", "m1", "project", "b/c")
	if fi, err := os.Lstat(testFile); err != nil {
	t.Fatalf("Lstat(%s): %v", testFile, err)
	} else if fi.Size() != 1 {
	t.Fatalf("%s has size %d", testFile, fi.Size())
	}

	ws := filepath.Join(dir, "ws")

	if _, _, err := Checkout(filepath.Join(dir, "mnt", "m1"), ws); err != nil {
	t.Fatal("Checkout m1:", err)
	}

	if dest, err := os.Readlink(filepath.Join(ws, "project")); err != nil {
	t.Fatal(err)
	} else if want := filepath.Join(dir, "mnt", "m1", "project"); dest != want {
	t.Fatalf("got %q, want %q", dest, want)
	}

	// Make sure we detect changed files. We have to be careful in
	// the test setup that no blobs are shared with newly
	// appearing files, or they'll be touched for being new files.

	added, changed, err := Checkout(filepath.Join(dir, "mnt", "m2"), ws)
	if err != nil {
	t.Fatal(err)
	}

	if want := []string{filepath.Join(dir, "mnt", "m2", "project/a")}; !reflect.DeepEqual(changed, want) {
	t.Errorf("got changed %v, want %v", changed, want)
	}

	if want := []string{
	filepath.Join(dir, "mnt", "m2", "project/new"),
	filepath.Join(dir, "mnt", "m2", "sub/d"),
	}; !reflect.DeepEqual(added, want) {
	t.Errorf("got added %v, want %v", added, want)
	}

	if dest, err := os.Readlink(filepath.Join(ws, "sub")); err != nil {
	t.Fatal(err)
	} else if want := filepath.Join(dir, "mnt", "m2", "sub"); dest != want {
	t.Fatalf("Readlink(ws/sub): got %q, want %q", dest, want)
	}
	}