Add a new integration test framework

I have had this living in a separate branch for now, but we need this in the main branch sooner rather than later.

One big advantage of this is that integration tests can live in any package, not just hugolib.

go.mod

@@ -60,9 +60,10 @@ require (
 	github.com/yuin/goldmark-highlighting v0.0.0-20200307114337-60d527fdb691
 	gocloud.dev v0.20.0
 	golang.org/x/image v0.0.0-20211028202545-6944b10bf410
-	golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d
+	golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
 	golang.org/x/text v0.3.7
+	golang.org/x/tools v0.1.9 // indirect
 	google.golang.org/api v0.63.0
 	gopkg.in/yaml.v2 v2.4.0
 )

go.sum

@@ -619,6 +619,7 @@ github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/yuin/goldmark v1.4.4 h1:zNWRjYUW32G9KirMXYHQHVNFkXvMI7LpgNW2AgYAoIs=
 github.com/yuin/goldmark v1.4.4/go.mod h1:rmuwmfZ0+bvzB24eSC//bk1R1Zp3hM0OXYv/G2LIilg=
 github.com/yuin/goldmark-highlighting v0.0.0-20200307114337-60d527fdb691 h1:VWSxtAiQNh3zgHJpdpkpVYjTPqRE3P6UZCOPa1nRDio=
@@ -695,6 +696,7 @@ golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.5.0/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181023162649-9b4f9f5ad519/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -744,6 +746,8 @@ golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420/go.mod h1:9nx3DQGgdP8bBQD5qx
 golang.org/x/net v0.0.0-20210614182718-04defd469f4e/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d h1:LO7XpTYMwTqxjLcGWPijK3vRXg1aWdlNOVOHRq45d7c=
 golang.org/x/net v0.0.0-20210813160813-60bc85c4be6d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f h1:OfiFi4JbukWwe3lzw+xunroH1mnC1e2Gy5cxNJApiSY=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190402181905-9f3314589c9a/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
@@ -845,6 +849,7 @@ golang.org/x/sys v0.0.0-20210823070655-63515b42dcdf/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20210908233432-aa78b53d3365/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211007075335-d3039528d8ac/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20211210111614-af8b64212486 h1:5hpz5aRr+W1erYCL5JRhSUBJRph7l9XkNveoExlrKYk=
 golang.org/x/sys v0.0.0-20211210111614-af8b64212486/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
@@ -924,6 +929,8 @@ golang.org/x/tools v0.1.2/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.3/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.4/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
 golang.org/x/tools v0.1.5/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/tools v0.1.9 h1:j9KsMiaP1c3B0OTQGth0/k+miLGTgLsAFUCrF2vLcF8=
+golang.org/x/tools v0.1.9/go.mod h1:nABZi5QlRsZVlzPpHl034qft6wpY4eDcsTt5AaioBiU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

hugolib/hugo_sites.go

@@ -117,6 +117,7 @@ func (h *HugoSites) getContentMaps() *pageMaps {
 // Only used in tests.
 type testCounters struct {
 	contentRenderCounter uint64
+	pageRenderCounter    uint64
 }
 
 func (h *testCounters) IncrContentRender() {
@@ -126,6 +127,13 @@ func (h *testCounters) IncrContentRender() {
 	atomic.AddUint64(&h.contentRenderCounter, 1)
 }
 
+func (h *testCounters) IncrPageRender() {
+	if h == nil {
+		return
+	}
+	atomic.AddUint64(&h.pageRenderCounter, 1)
+}
+
 type fatalErrorHandler struct {
 	mu sync.Mutex
 

hugolib/integrationtest_builder.go

@@ -0,0 +1,448 @@
+package hugolib
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+
+	jww "github.com/spf13/jwalterweatherman"
+
+	qt "github.com/frankban/quicktest"
+	"github.com/fsnotify/fsnotify"
+	"github.com/gohugoio/hugo/common/herrors"
+	"github.com/gohugoio/hugo/common/hexec"
+	"github.com/gohugoio/hugo/common/loggers"
+	"github.com/gohugoio/hugo/config"
+	"github.com/gohugoio/hugo/config/security"
+	"github.com/gohugoio/hugo/deps"
+	"github.com/gohugoio/hugo/helpers"
+	"github.com/gohugoio/hugo/htesting"
+	"github.com/gohugoio/hugo/hugofs"
+	"github.com/spf13/afero"
+	"golang.org/x/tools/txtar"
+)
+
+func NewIntegrationTestBuilder(conf IntegrationTestConfig) *IntegrationTestBuilder {
+	data := txtar.Parse([]byte(conf.TxtarString))
+
+	c, ok := conf.T.(*qt.C)
+	if !ok {
+		c = qt.New(conf.T)
+	}
+
+	if conf.NeedsOsFS {
+		doClean := true
+		tempDir, clean, err := htesting.CreateTempDir(hugofs.Os, "hugo-integration-test")
+		c.Assert(err, qt.IsNil)
+		conf.WorkingDir = filepath.Join(tempDir, conf.WorkingDir)
+		if doClean {
+			c.Cleanup(clean)
+		}
+	}
+
+	return &IntegrationTestBuilder{
+		Cfg:  conf,
+		C:    c,
+		data: data,
+	}
+}
+
+// IntegrationTestBuilder is a (partial) rewrite of sitesBuilder.
+// The main problem with the "old" one was that it was that the test data was often a little hidden,
+// so it became hard to look at a test and determine what it should do, especially coming back to the
+// test after a year or so.
+type IntegrationTestBuilder struct {
+	*qt.C
+
+	data *txtar.Archive
+
+	fs *hugofs.Fs
+	H  *HugoSites
+
+	Cfg IntegrationTestConfig
+
+	changedFiles []string
+	createdFiles []string
+	removedFiles []string
+	renamedFiles []string
+
+	buildCount int
+	counters   *testCounters
+	logBuff    lockingBuffer
+
+	builderInit sync.Once
+}
+
+type lockingBuffer struct {
+	sync.Mutex
+	bytes.Buffer
+}
+
+func (b *lockingBuffer) Write(p []byte) (n int, err error) {
+	b.Lock()
+	n, err = b.Buffer.Write(p)
+	b.Unlock()
+	return
+}
+
+func (s *IntegrationTestBuilder) AssertLogContains(text string) {
+	s.Helper()
+	s.Assert(s.logBuff.String(), qt.Contains, text)
+}
+
+func (s *IntegrationTestBuilder) AssertBuildCountData(count int) {
+	s.Helper()
+	s.Assert(s.H.init.data.InitCount(), qt.Equals, count)
+}
+
+func (s *IntegrationTestBuilder) AssertBuildCountGitInfo(count int) {
+	s.Helper()
+	s.Assert(s.H.init.gitInfo.InitCount(), qt.Equals, count)
+}
+
+func (s *IntegrationTestBuilder) AssertBuildCountLayouts(count int) {
+	s.Helper()
+	s.Assert(s.H.init.layouts.InitCount(), qt.Equals, count)
+}
+
+func (s *IntegrationTestBuilder) AssertBuildCountTranslations(count int) {
+	s.Helper()
+	s.Assert(s.H.init.translations.InitCount(), qt.Equals, count)
+}
+
+func (s *IntegrationTestBuilder) AssertFileContent(filename string, matches ...string) {
+	s.Helper()
+	content := strings.TrimSpace(s.FileContent(filename))
+	for _, m := range matches {
+		lines := strings.Split(m, "\n")
+		for _, match := range lines {
+			match = strings.TrimSpace(match)
+			if match == "" || strings.HasPrefix(match, "#") {
+				continue
+			}
+			s.Assert(content, qt.Contains, match, qt.Commentf(content))
+		}
+	}
+}
+
+func (s *IntegrationTestBuilder) AssertDestinationExists(filename string, b bool) {
+	checker := qt.IsTrue
+	if !b {
+		checker = qt.IsFalse
+	}
+	s.Assert(s.destinationExists(filepath.Clean(filename)), checker)
+}
+
+func (s *IntegrationTestBuilder) destinationExists(filename string) bool {
+	b, err := helpers.Exists(filename, s.fs.Destination)
+	if err != nil {
+		panic(err)
+	}
+	return b
+}
+
+func (s *IntegrationTestBuilder) AssertIsFileError(err error) {
+	var ferr *herrors.ErrorWithFileContext
+	s.Assert(err, qt.ErrorAs, &ferr)
+}
+
+func (s *IntegrationTestBuilder) AssertRenderCountContent(count int) {
+	s.Helper()
+	s.Assert(s.counters.contentRenderCounter, qt.Equals, uint64(count))
+}
+
+func (s *IntegrationTestBuilder) AssertRenderCountPage(count int) {
+	s.Helper()
+	s.Assert(s.counters.pageRenderCounter, qt.Equals, uint64(count))
+}
+
+func (s *IntegrationTestBuilder) Build() *IntegrationTestBuilder {
+	s.Helper()
+	_, err := s.BuildE()
+	if s.Cfg.Verbose {
+		fmt.Println(s.logBuff.String())
+	}
+	s.Assert(err, qt.IsNil)
+	return s
+}
+
+func (s *IntegrationTestBuilder) BuildE() (*IntegrationTestBuilder, error) {
+	s.Helper()
+	s.initBuilder()
+	err := s.build(BuildCfg{})
+	return s, err
+}
+
+type IntegrationTestDebugConfig struct {
+	Out io.Writer
+
+	PrintDestinationFs bool
+	PrintPagemap       bool
+
+	PrefixDestinationFs string
+	PrefixPagemap       string
+}
+
+func (s *IntegrationTestBuilder) EditFileReplace(filename string, replacementFunc func(s string) string) *IntegrationTestBuilder {
+	absFilename := s.absFilename(filename)
+	b, err := afero.ReadFile(s.fs.Source, absFilename)
+	s.Assert(err, qt.IsNil)
+	s.changedFiles = append(s.changedFiles, absFilename)
+	oldContent := string(b)
+	s.writeSource(absFilename, replacementFunc(oldContent))
+	return s
+}
+
+func (s *IntegrationTestBuilder) EditFiles(filenameContent ...string) *IntegrationTestBuilder {
+	for i := 0; i < len(filenameContent); i += 2 {
+		filename, content := filepath.FromSlash(filenameContent[i]), filenameContent[i+1]
+		absFilename := s.absFilename(filename)
+		s.changedFiles = append(s.changedFiles, absFilename)
+		s.writeSource(absFilename, content)
+	}
+	return s
+}
+
+func (s *IntegrationTestBuilder) AddFiles(filenameContent ...string) *IntegrationTestBuilder {
+	for i := 0; i < len(filenameContent); i += 2 {
+		filename, content := filepath.FromSlash(filenameContent[i]), filenameContent[i+1]
+		absFilename := s.absFilename(filename)
+		s.createdFiles = append(s.createdFiles, absFilename)
+		s.writeSource(absFilename, content)
+	}
+	return s
+}
+
+func (s *IntegrationTestBuilder) RemoveFiles(filenames ...string) *IntegrationTestBuilder {
+	for _, filename := range filenames {
+		absFilename := s.absFilename(filename)
+		s.removedFiles = append(s.removedFiles, absFilename)
+		s.Assert(s.fs.Source.Remove(absFilename), qt.IsNil)
+
+	}
+
+	return s
+}
+
+func (s *IntegrationTestBuilder) RenameFile(old, new string) *IntegrationTestBuilder {
+	absOldFilename := s.absFilename(old)
+	absNewFilename := s.absFilename(new)
+	s.renamedFiles = append(s.renamedFiles, absOldFilename)
+	s.createdFiles = append(s.createdFiles, absNewFilename)
+	s.Assert(s.fs.Source.Rename(absOldFilename, absNewFilename), qt.IsNil)
+	return s
+}
+
+func (s *IntegrationTestBuilder) FileContent(filename string) string {
+	s.Helper()
+	filename = filepath.FromSlash(filename)
+	if !strings.HasPrefix(filename, s.Cfg.WorkingDir) {
+		filename = filepath.Join(s.Cfg.WorkingDir, filename)
+	}
+	return s.readDestination(s, s.fs, filename)
+}
+
+func (s *IntegrationTestBuilder) initBuilder() {
+	s.builderInit.Do(func() {
+		var afs afero.Fs
+		if s.Cfg.NeedsOsFS {
+			afs = afero.NewOsFs()
+		} else {
+			afs = afero.NewMemMapFs()
+		}
+
+		if s.Cfg.LogLevel == 0 {
+			s.Cfg.LogLevel = jww.LevelWarn
+		}
+
+		logger := loggers.NewBasicLoggerForWriter(s.Cfg.LogLevel, &s.logBuff)
+
+		fs := hugofs.NewFrom(afs, config.New())
+
+		for _, f := range s.data.Files {
+			filename := filepath.Join(s.Cfg.WorkingDir, f.Name)
+			s.Assert(afs.MkdirAll(filepath.Dir(filename), 0777), qt.IsNil)
+			s.Assert(afero.WriteFile(afs, filename, bytes.TrimSuffix(f.Data, []byte("\n")), 0666), qt.IsNil)
+		}
+
+		cfg, _, err := LoadConfig(
+			ConfigSourceDescriptor{
+				WorkingDir: s.Cfg.WorkingDir,
+				Fs:         afs,
+				Logger:     logger,
+				Environ:    []string{},
+				Filename:   "config.toml",
+			},
+			func(cfg config.Provider) error {
+				return nil
+			},
+		)
+
+		s.Assert(err, qt.IsNil)
+
+		cfg.Set("workingDir", s.Cfg.WorkingDir)
+
+		depsCfg := deps.DepsCfg{Cfg: cfg, Fs: fs, Running: s.Cfg.Running, Logger: logger}
+		sites, err := NewHugoSites(depsCfg)
+		s.Assert(err, qt.IsNil)
+
+		s.H = sites
+		s.fs = fs
+
+		if s.Cfg.NeedsNpmInstall {
+			wd, _ := os.Getwd()
+			s.Assert(os.Chdir(s.Cfg.WorkingDir), qt.IsNil)
+			s.C.Cleanup(func() { os.Chdir(wd) })
+			sc := security.DefaultConfig
+			sc.Exec.Allow = security.NewWhitelist("npm")
+			ex := hexec.New(sc)
+			command, err := ex.New("npm", "install")
+			s.Assert(err, qt.IsNil)
+			s.Assert(command.Run(), qt.IsNil)
+
+		}
+	})
+}
+
+func (s *IntegrationTestBuilder) absFilename(filename string) string {
+	filename = filepath.FromSlash(filename)
+	if filepath.IsAbs(filename) {
+		return filename
+	}
+	if s.Cfg.WorkingDir != "" && !strings.HasPrefix(filename, s.Cfg.WorkingDir) {
+		filename = filepath.Join(s.Cfg.WorkingDir, filename)
+	}
+	return filename
+}
+
+func (s *IntegrationTestBuilder) build(cfg BuildCfg) error {
+	s.Helper()
+	defer func() {
+		s.changedFiles = nil
+		s.createdFiles = nil
+		s.removedFiles = nil
+		s.renamedFiles = nil
+	}()
+
+	changeEvents := s.changeEvents()
+	s.logBuff.Reset()
+	s.counters = &testCounters{}
+	cfg.testCounters = s.counters
+
+	if s.buildCount > 0 && (len(changeEvents) == 0) {
+		return nil
+	}
+
+	s.buildCount++
+
+	err := s.H.Build(cfg, changeEvents...)
+	if err != nil {
+		return err
+	}
+	logErrorCount := s.H.NumLogErrors()
+	if logErrorCount > 0 {
+		return fmt.Errorf("logged %d error(s): %s", logErrorCount, s.logBuff.String())
+	}
+
+	return nil
+}
+
+func (s *IntegrationTestBuilder) changeEvents() []fsnotify.Event {
+	var events []fsnotify.Event
+	for _, v := range s.removedFiles {
+		events = append(events, fsnotify.Event{
+			Name: v,
+			Op:   fsnotify.Remove,
+		})
+	}
+	for _, v := range s.renamedFiles {
+		events = append(events, fsnotify.Event{
+			Name: v,
+			Op:   fsnotify.Rename,
+		})
+	}
+	for _, v := range s.changedFiles {
+		events = append(events, fsnotify.Event{
+			Name: v,
+			Op:   fsnotify.Write,
+		})
+	}
+	for _, v := range s.createdFiles {
+		events = append(events, fsnotify.Event{
+			Name: v,
+			Op:   fsnotify.Create,
+		})
+	}
+
+	return events
+}
+
+func (s *IntegrationTestBuilder) readDestination(t testing.TB, fs *hugofs.Fs, filename string) string {
+	t.Helper()
+	return s.readFileFromFs(t, fs.Destination, filename)
+}
+
+func (s *IntegrationTestBuilder) readFileFromFs(t testing.TB, fs afero.Fs, filename string) string {
+	t.Helper()
+	filename = filepath.Clean(filename)
+	b, err := afero.ReadFile(fs, filename)
+	if err != nil {
+		// Print some debug info
+		hadSlash := strings.HasPrefix(filename, helpers.FilePathSeparator)
+		start := 0
+		if hadSlash {
+			start = 1
+		}
+		end := start + 1
+
+		parts := strings.Split(filename, helpers.FilePathSeparator)
+		if parts[start] == "work" {
+			end++
+		}
+
+		s.Assert(err, qt.IsNil)
+
+	}
+	return string(b)
+}
+
+func (s *IntegrationTestBuilder) writeSource(filename, content string) {
+	s.Helper()
+	s.writeToFs(s.fs.Source, filename, content)
+}
+
+func (s *IntegrationTestBuilder) writeToFs(fs afero.Fs, filename, content string) {
+	s.Helper()
+	if err := afero.WriteFile(fs, filepath.FromSlash(filename), []byte(content), 0755); err != nil {
+		s.Fatalf("Failed to write file: %s", err)
+	}
+}
+
+type IntegrationTestConfig struct {
+	T testing.TB
+
+	// The files to use on txtar format, see
+	// https://pkg.go.dev/golang.org/x/exp/cmd/txtar
+	TxtarString string
+
+	// Whether to simulate server mode.
+	Running bool
+
+	// Will print the log buffer after the build
+	Verbose bool
+
+	LogLevel jww.Threshold
+
+	// Whether it needs the real file system (e.g. for js.Build tests).
+	NeedsOsFS bool
+
+	// Whether to run npm install before Build.
+	NeedsNpmInstall bool
+
+	WorkingDir string
+}

hugolib/site.go

@@ -1719,6 +1719,7 @@ func (s *Site) renderAndWriteXML(statCounter *uint64, name string, targetPath st
 
 func (s *Site) renderAndWritePage(statCounter *uint64, name string, targetPath string, p *pageState, templ tpl.Template) error {
 	s.Log.Debugf("Render %s to %q", name, targetPath)
+	s.h.IncrPageRender()
 	renderBuffer := bp.GetBuffer()
 	defer bp.PutBuffer(renderBuffer)
 

lazy/init.go

@@ -16,6 +16,7 @@ package lazy
 import (
 	"context"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/pkg/errors"
@@ -28,6 +29,9 @@ func New() *Init {
 
 // Init holds a graph of lazily initialized dependencies.
 type Init struct {
+	// Used in tests
+	initCount uint64
+
 	mu sync.Mutex
 
 	prev     *Init
@@ -47,6 +51,12 @@ func (ini *Init) Add(initFn func() (interface{}, error)) *Init {
 	return ini.add(false, initFn)
 }
 
+// InitCount gets the number of this this Init has been initialized.
+func (ini *Init) InitCount() int {
+	i := atomic.LoadUint64(&ini.initCount)
+	return int(i)
+}
+
 // AddWithTimeout is same as Add, but with a timeout that aborts initialization.
 func (ini *Init) AddWithTimeout(timeout time.Duration, f func(ctx context.Context) (interface{}, error)) *Init {
 	return ini.Add(func() (interface{}, error) {
@@ -77,6 +87,7 @@ func (ini *Init) Do() (interface{}, error) {
 	}
 
 	ini.init.Do(func() {
+		atomic.AddUint64(&ini.initCount, 1)
 		prev := ini.prev
 		if prev != nil {
 			// A branch. Initialize the ancestors.