integration_test.go - third_party/github.com/protocolbuffers/protobuf-go - Git at Google

 // Copyright 2019 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 main

 import (
 	"archive/tar"
 	"archive/zip"
 	"bytes"
 	"compress/gzip"
 	"crypto/sha256"
 	"flag"
 	"fmt"
 	"io"
 	"io/fs"
 	"net/http"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"reflect"
 	"regexp"
 	"runtime"
 	"runtime/debug"
 	"strings"
 	"sync"
 	"testing"
 	"time"

 	"google.golang.org/protobuf/internal/version"
 )

 var (
 	regenerate   = flag.Bool("regenerate", false, "regenerate files")
 	buildRelease = flag.Bool("buildRelease", false, "build release binaries")

 	protobufVersion = "27.0-rc1"

 	golangVersions = func() []string {
 		// Version policy: same version as is in the x/ repos' go.mod.
 		return []string{
 			"1.17.13",
 			"1.18.10",
 			"1.19.13",
 			"1.20.12",
 			"1.21.5",
 		}
 	}()
 	golangLatest = golangVersions[len(golangVersions)-1]

 	staticcheckVersion = "2023.1.6"
 	staticcheckSHA256s = map[string]string{
 		"darwin/amd64": "b14a0cbd3c238713f5f9db41550893ea7d75d8d7822491c7f4e33e2fe43f6305",
 		"darwin/arm64": "f1c869abe6be2c6ab727dc9d6049766c947534766d71a1798c12a37526ea2b6f",
 		"linux/386":    "02859a7c44c7b5ab41a70d9b8107c01ab8d2c94075bae3d0b02157aff743ca42",
 		"linux/amd64":  "45337834da5dc7b8eff01cb6b3837e3759503cfbb8edf36b09e42f32bccb1f6e",
 	}

 	// purgeTimeout determines the maximum age of unused sub-directories.
 	purgeTimeout = 30 * 24 * time.Hour // 1 month

 	// Variables initialized by mustInitDeps.
 	modulePath   string
 	protobufPath string
 )

 func TestIntegration(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping integration test in short mode")
 	}
 	if os.Getenv("GO_BUILDER_NAME") != "" {
 		// To start off, run on longtest builders, not longtest-race ones.
 		if race() {
 			t.Skip("skipping integration test in race mode on builders")
 		}
 		// When on a builder, run even if it's not explicitly requested
 		// provided our caller isn't already running it.
 		if os.Getenv("GO_PROTOBUF_INTEGRATION_TEST_RUNNING") == "1" {
 			t.Skip("protobuf integration test is already running, skipping nested invocation")
 		}
 		os.Setenv("GO_PROTOBUF_INTEGRATION_TEST_RUNNING", "1")
 	} else if flag.Lookup("test.run").Value.String() != "^TestIntegration$" {
 		t.Skip("not running integration test if not explicitly requested via test.bash")
 	}

 	mustInitDeps(t)
 	mustHandleFlags(t)

 	// Report dirt in the working tree quickly, rather than after
 	// going through all the presubmits.
 	//
 	// Fail the test late, so we can test uncommitted changes with -failfast.
 	gitDiff := mustRunCommand(t, "git", "diff", "HEAD")
 	if strings.TrimSpace(gitDiff) != "" {
 		fmt.Printf("WARNING: working tree contains uncommitted changes:\n%v\n", gitDiff)
 	}
 	gitUntracked := mustRunCommand(t, "git", "ls-files", "--others", "--exclude-standard")
 	if strings.TrimSpace(gitUntracked) != "" {
 		fmt.Printf("WARNING: working tree contains untracked files:\n%v\n", gitUntracked)
 	}

 	// Do the relatively fast checks up-front.
 	t.Run("GeneratedGoFiles", func(t *testing.T) {
 		diff := mustRunCommand(t, "go", "run", "-tags", "protolegacy", "./internal/cmd/generate-types")
 		if strings.TrimSpace(diff) != "" {
 			t.Fatalf("stale generated files:\n%v", diff)
 		}
 		diff = mustRunCommand(t, "go", "run", "-tags", "protolegacy", "./internal/cmd/generate-protos")
 		if strings.TrimSpace(diff) != "" {
 			t.Fatalf("stale generated files:\n%v", diff)
 		}
 	})
 	t.Run("FormattedGoFiles", func(t *testing.T) {
 		files := strings.Split(strings.TrimSpace(mustRunCommand(t, "git", "ls-files", "*.go")), "\n")
 		diff := mustRunCommand(t, append([]string{"gofmt", "-d"}, files...)...)
 		if strings.TrimSpace(diff) != "" {
 			t.Fatalf("unformatted source files:\n%v", diff)
 		}
 	})
 	t.Run("CopyrightHeaders", func(t *testing.T) {
 		files := strings.Split(strings.TrimSpace(mustRunCommand(t, "git", "ls-files", "*.go", "*.proto")), "\n")
 		mustHaveCopyrightHeader(t, files)
 	})

 	var wg sync.WaitGroup
 	sema := make(chan bool, (runtime.NumCPU()+1)/2)
 	for i := range golangVersions {
 		goVersion := golangVersions[i]
 		goLabel := "Go" + goVersion
 		runGo := func(label string, cmd command, args ...string) {
 			wg.Add(1)
 			sema <- true
 			go func() {
 				defer wg.Done()
 				defer func() { <-sema }()
 				t.Run(goLabel+"/"+label, func(t *testing.T) {
 					args[0] += goVersion
 					cmd.mustRun(t, args...)
 				})
 			}()
 		}

 		runGo("Normal", command{}, "go", "test", "-race", "./...")
 		runGo("PureGo", command{}, "go", "test", "-race", "-tags", "purego", "./...")
 		runGo("Reflect", command{}, "go", "test", "-race", "-tags", "protoreflect", "./...")
 		if goVersion == golangLatest {
 			runGo("ProtoLegacyRace", command{}, "go", "test", "-race", "-tags", "protolegacy", "./...")
 			runGo("ProtoLegacy", command{}, "go", "test", "-tags", "protolegacy", "./...")
 			runGo("ProtocGenGo", command{Dir: "cmd/protoc-gen-go/testdata"}, "go", "test")
 			runGo("Conformance", command{Dir: "internal/conformance"}, "go", "test", "-execute")

 			// Only run the 32-bit compatibility tests for Linux;
 			// avoid Darwin since 10.15 dropped support i386 code execution.
 			if runtime.GOOS == "linux" {
 				runGo("Arch32Bit", command{Env: append(os.Environ(), "GOARCH=386")}, "go", "test", "./...")
 			}
 		}
 	}
 	wg.Wait()

 	t.Run("GoStaticCheck", func(t *testing.T) {
 		checks := []string{
 			"all",     // start with all checks enabled
 			"-SA1019", // disable deprecated usage check
 			"-S*",     // disable code simplification checks
 			"-ST*",    // disable coding style checks
 			"-U*",     // disable unused declaration checks
 		}
 		out := mustRunCommand(t, "staticcheck", "-checks="+strings.Join(checks, ","), "-fail=none", "./...")

 		// Filter out findings from certain paths.
 		var findings []string
 		for _, finding := range strings.Split(strings.TrimSpace(out), "\n") {
 			switch {
 			case strings.HasPrefix(finding, "internal/testprotos/legacy/"):
 			default:
 				findings = append(findings, finding)
 			}
 		}
 		if len(findings) > 0 {
 			t.Fatalf("staticcheck findings:\n%v", strings.Join(findings, "\n"))
 		}
 	})
 	t.Run("CommittedGitChanges", func(t *testing.T) {
 		if strings.TrimSpace(gitDiff) != "" {
 			t.Fatalf("uncommitted changes")
 		}
 	})
 	t.Run("TrackedGitFiles", func(t *testing.T) {
 		if strings.TrimSpace(gitUntracked) != "" {
 			t.Fatalf("untracked files")
 		}
 	})
 }

 func mustInitDeps(t *testing.T) {
 	check := func(err error) {
 		t.Helper()
 		if err != nil {
 			t.Fatal(err)
 		}
 	}

 	// Determine the directory to place the test directory.
 	repoRoot, err := os.Getwd()
 	check(err)
 	testDir := filepath.Join(repoRoot, ".cache")
 	check(os.MkdirAll(testDir, 0775))

 	// Delete the current directory if non-empty,
 	// which only occurs if a dependency failed to initialize properly.
 	var workingDir string
 	finishedDirs := map[string]bool{}
 	defer func() {
 		if workingDir != "" {
 			os.RemoveAll(workingDir) // best-effort
 		}
 	}()
 	startWork := func(name string) string {
 		workingDir = filepath.Join(testDir, name)
 		return workingDir
 	}
 	finishWork := func() {
 		finishedDirs[workingDir] = true
 		workingDir = ""
 	}

 	// Delete other sub-directories that are no longer relevant.
 	defer func() {
 		now := time.Now()
 		fis, _ := os.ReadDir(testDir)
 		for _, fi := range fis {
 			dir := filepath.Join(testDir, fi.Name())
 			if finishedDirs[dir] {
 				os.Chtimes(dir, now, now) // best-effort
 				continue
 			}
 			fii, err := fi.Info()
 			check(err)
 			if now.Sub(fii.ModTime()) < purgeTimeout {
 				continue
 			}
 			fmt.Printf("delete %v\n", fi.Name())
 			os.RemoveAll(dir) // best-effort
 		}
 	}()

 	// The bin directory contains symlinks to each tool by version.
 	// It is safe to delete this directory and run the test script from scratch.
 	binPath := startWork("bin")
 	check(os.RemoveAll(binPath))
 	check(os.Mkdir(binPath, 0775))
 	check(os.Setenv("PATH", binPath+":"+os.Getenv("PATH")))
 	registerBinary := func(name, path string) {
 		check(os.Symlink(path, filepath.Join(binPath, name)))
 	}
 	finishWork()

 	// Get the protobuf toolchain.
 	protobufPath = startWork("protobuf-" + protobufVersion)
 	if _, err := os.Stat(protobufPath); err != nil {
 		fmt.Printf("download %v\n", filepath.Base(protobufPath))
 		checkoutVersion := protobufVersion
 		if isCommit := strings.Trim(protobufVersion, "0123456789abcdef") == ""; !isCommit {
 			// release tags have "v" prefix
 			checkoutVersion = "v" + protobufVersion
 		}
 		command{Dir: testDir}.mustRun(t, "git", "clone", "https://github.com/protocolbuffers/protobuf", "protobuf-"+protobufVersion)
 		command{Dir: protobufPath}.mustRun(t, "git", "checkout", checkoutVersion)

 		if os.Getenv("GO_BUILDER_NAME") != "" {
 			// If this is running on the Go build infrastructure,
 			// use pre-built versions of these binaries that the
 			// builders are configured to provide in $PATH.
 			protocPath, err := exec.LookPath("protoc")
 			check(err)
 			confTestRunnerPath, err := exec.LookPath("conformance_test_runner")
 			check(err)
 			check(os.MkdirAll(filepath.Join(protobufPath, "bazel-bin", "conformance"), 0775))
 			check(os.Symlink(protocPath, filepath.Join(protobufPath, "bazel-bin", "protoc")))
 			check(os.Symlink(confTestRunnerPath, filepath.Join(protobufPath, "bazel-bin", "conformance", "conformance_test_runner")))
 		} else {
 			// In other environments, download and build the protobuf toolchain.
 			// We avoid downloading the pre-compiled binaries since they do not contain
 			// the conformance test runner.
 			fmt.Printf("build %v\n", filepath.Base(protobufPath))
 			env := os.Environ()
 			args := []string{
 				"bazel", "build",
 				":protoc",
 				"//conformance:conformance_test_runner",
 			}
 			if runtime.GOOS == "darwin" {
 				// Adding this environment variable appears to be necessary for macOS builds.
 				env = append(env, "CC=clang")
 				// And this flag.
 				args = append(args,
 					"--macos_minimum_os=13.0",
 					"--host_macos_minimum_os=13.0",
 				)
 			}
 			command{
 				Dir: protobufPath,
 				Env: env,
 			}.mustRun(t, args...)
 		}
 	}
 	check(os.Setenv("PROTOBUF_ROOT", protobufPath)) // for generate-protos
 	registerBinary("conform-test-runner", filepath.Join(protobufPath, "bazel-bin", "conformance", "conformance_test_runner"))
 	registerBinary("protoc", filepath.Join(protobufPath, "bazel-bin", "protoc"))
 	finishWork()

 	// Download each Go toolchain version.
 	for _, v := range golangVersions {
 		goDir := startWork("go" + v)
 		if _, err := os.Stat(goDir); err != nil {
 			fmt.Printf("download %v\n", filepath.Base(goDir))
 			url := fmt.Sprintf("https://dl.google.com/go/go%v.%v-%v.tar.gz", v, runtime.GOOS, runtime.GOARCH)
 			downloadArchive(check, goDir, url, "go", "") // skip SHA256 check as we fetch over https from a trusted domain
 		}
 		registerBinary("go"+v, filepath.Join(goDir, "bin", "go"))
 		finishWork()
 	}
 	registerBinary("go", filepath.Join(testDir, "go"+golangLatest, "bin", "go"))
 	registerBinary("gofmt", filepath.Join(testDir, "go"+golangLatest, "bin", "gofmt"))

 	// Download the staticcheck tool.
 	checkDir := startWork("staticcheck-" + staticcheckVersion)
 	if _, err := os.Stat(checkDir); err != nil {
 		fmt.Printf("download %v\n", filepath.Base(checkDir))
 		url := fmt.Sprintf("https://github.com/dominikh/go-tools/releases/download/%v/staticcheck_%v_%v.tar.gz", staticcheckVersion, runtime.GOOS, runtime.GOARCH)
 		downloadArchive(check, checkDir, url, "staticcheck", staticcheckSHA256s[runtime.GOOS+"/"+runtime.GOARCH])
 	}
 	registerBinary("staticcheck", filepath.Join(checkDir, "staticcheck"))
 	finishWork()

 	// GitHub actions sets GOROOT, which confuses invocations of the Go toolchain.
 	// Explicitly clear GOROOT, so each toolchain uses their default GOROOT.
 	check(os.Unsetenv("GOROOT"))

 	// Set a cache directory outside the test directory.
 	check(os.Setenv("GOCACHE", filepath.Join(repoRoot, ".gocache")))
 }

 func downloadFile(check func(error), dstPath, srcURL string, perm fs.FileMode) {
 	resp, err := http.Get(srcURL)
 	check(err)
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(io.LimitReader(resp.Body, 4<<10))
 		check(fmt.Errorf("GET %q: non-200 OK status code: %v body: %q", srcURL, resp.Status, body))
 	}

 	check(os.MkdirAll(filepath.Dir(dstPath), 0775))
 	f, err := os.OpenFile(dstPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
 	check(err)

 	_, err = io.Copy(f, resp.Body)
 	check(err)

 	check(f.Close())
 }

 func downloadArchive(check func(error), dstPath, srcURL, skipPrefix, wantSHA256 string) {
 	check(os.RemoveAll(dstPath))

 	resp, err := http.Get(srcURL)
 	check(err)
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(io.LimitReader(resp.Body, 4<<10))
 		check(fmt.Errorf("GET %q: non-200 OK status code: %v body: %q", srcURL, resp.Status, body))
 	}

 	var r io.Reader = resp.Body
 	if wantSHA256 != "" {
 		b, err := io.ReadAll(resp.Body)
 		check(err)
 		r = bytes.NewReader(b)

 		if gotSHA256 := fmt.Sprintf("%x", sha256.Sum256(b)); gotSHA256 != wantSHA256 {
 			check(fmt.Errorf("checksum validation error:\ngot  %v\nwant %v", gotSHA256, wantSHA256))
 		}
 	}

 	zr, err := gzip.NewReader(r)
 	check(err)

 	tr := tar.NewReader(zr)
 	for {
 		h, err := tr.Next()
 		if err == io.EOF {
 			return
 		}
 		check(err)

 		// Skip directories or files outside the prefix directory.
 		if len(skipPrefix) > 0 {
 			if !strings.HasPrefix(h.Name, skipPrefix) {
 				continue
 			}
 			if len(h.Name) > len(skipPrefix) && h.Name[len(skipPrefix)] != '/' {
 				continue
 			}
 		}

 		path := strings.TrimPrefix(strings.TrimPrefix(h.Name, skipPrefix), "/")
 		path = filepath.Join(dstPath, filepath.FromSlash(path))
 		mode := os.FileMode(h.Mode & 0777)
 		switch h.Typeflag {
 		case tar.TypeReg:
 			b, err := io.ReadAll(tr)
 			check(err)
 			check(os.WriteFile(path, b, mode))
 		case tar.TypeDir:
 			check(os.Mkdir(path, mode))
 		}
 	}
 }

 func mustHandleFlags(t *testing.T) {
 	if *regenerate {
 		t.Run("Generate", func(t *testing.T) {
 			fmt.Print(mustRunCommand(t, "go", "generate", "./internal/cmd/generate-types"))
 			fmt.Print(mustRunCommand(t, "go", "generate", "./internal/cmd/generate-protos"))
 			files := strings.Split(strings.TrimSpace(mustRunCommand(t, "git", "ls-files", "*.go")), "\n")
 			mustRunCommand(t, append([]string{"gofmt", "-w"}, files...)...)
 		})
 	}
 	if *buildRelease {
 		t.Run("BuildRelease", func(t *testing.T) {
 			v := version.String()
 			for _, goos := range []string{"linux", "darwin", "windows"} {
 				for _, goarch := range []string{"386", "amd64", "arm64"} {
 					// Avoid Darwin since 10.15 dropped support for i386.
 					if goos == "darwin" && goarch == "386" {
 						continue
 					}

 					binPath := filepath.Join("bin", fmt.Sprintf("protoc-gen-go.%v.%v.%v", v, goos, goarch))

 					// Build the binary.
 					cmd := command{Env: append(os.Environ(), "GOOS="+goos, "GOARCH="+goarch)}
 					cmd.mustRun(t, "go", "build", "-trimpath", "-ldflags", "-s -w -buildid=", "-o", binPath, "./cmd/protoc-gen-go")

 					// Archive and compress the binary.
 					in, err := os.ReadFile(binPath)
 					if err != nil {
 						t.Fatal(err)
 					}
 					out := new(bytes.Buffer)
 					suffix := ""
 					comment := fmt.Sprintf("protoc-gen-go VERSION=%v GOOS=%v GOARCH=%v", v, goos, goarch)
 					switch goos {
 					case "windows":
 						suffix = ".zip"
 						zw := zip.NewWriter(out)
 						zw.SetComment(comment)
 						fw, _ := zw.Create("protoc-gen-go.exe")
 						fw.Write(in)
 						zw.Close()
 					default:
 						suffix = ".tar.gz"
 						gz, _ := gzip.NewWriterLevel(out, gzip.BestCompression)
 						gz.Comment = comment
 						tw := tar.NewWriter(gz)
 						tw.WriteHeader(&tar.Header{
 							Name: "protoc-gen-go",
 							Mode: int64(0775),
 							Size: int64(len(in)),
 						})
 						tw.Write(in)
 						tw.Close()
 						gz.Close()
 					}
 					if err := os.WriteFile(binPath+suffix, out.Bytes(), 0664); err != nil {
 						t.Fatal(err)
 					}
 				}
 			}
 		})
 	}
 	if *regenerate || *buildRelease {
 		t.SkipNow()
 	}
 }

 var copyrightRegex = []*regexp.Regexp{
 	regexp.MustCompile(`^// Copyright \d\d\d\d 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\.
 `),
 	// Generated .pb.go files from main protobuf repo.
 	regexp.MustCompile(`^// Protocol Buffers - Google's data interchange format
 // Copyright \d\d\d\d Google Inc\.  All rights reserved\.
 `),
 }

 func mustHaveCopyrightHeader(t *testing.T, files []string) {
 	var bad []string
 File:
 	for _, file := range files {
 		if strings.HasSuffix(file, "internal/testprotos/conformance/editions/test_messages_edition2023.pb.go") {
 			// TODO(lassefolger) the underlying proto file is checked into
 			// the protobuf repo without a copyright header. Fix is pending but
 			// might require a release.
 			continue
 		}
 		b, err := os.ReadFile(file)
 		if err != nil {
 			t.Fatal(err)
 		}
 		for _, re := range copyrightRegex {
 			if loc := re.FindIndex(b); loc != nil && loc[0] == 0 {
 				continue File
 			}
 		}
 		bad = append(bad, file)
 	}
 	if len(bad) > 0 {
 		t.Fatalf("files with missing/bad copyright headers:\n  %v", strings.Join(bad, "\n  "))
 	}
 }

 type command struct {
 	Dir string
 	Env []string
 }

 func (c command) mustRun(t *testing.T, args ...string) string {
 	t.Helper()
 	stdout := new(bytes.Buffer)
 	stderr := new(bytes.Buffer)
 	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Dir = "."
 	if c.Dir != "" {
 		cmd.Dir = c.Dir
 	}
 	cmd.Env = os.Environ()
 	if c.Env != nil {
 		cmd.Env = c.Env
 	}
 	cmd.Env = append(cmd.Env, "PWD="+cmd.Dir)
 	cmd.Stdout = stdout
 	cmd.Stderr = stderr
 	if err := cmd.Run(); err != nil {
 		t.Fatalf("executing (%v): %v\n%s%s", strings.Join(args, " "), err, stdout.String(), stderr.String())
 	}
 	return stdout.String()
 }

 func mustRunCommand(t *testing.T, args ...string) string {
 	t.Helper()
 	return command{}.mustRun(t, args...)
 }

 // race is an approximation of whether the race detector is on.
 // It's used to skip the integration test on builders, without
 // preventing the integration test from running under the race
 // detector as a '//go:build !race' build constraint would.
 func race() bool {
 	bi, ok := debug.ReadBuildInfo()
 	if !ok {
 		return false
 	}
 	// Use reflect because the debug.BuildInfo.Settings field
 	// isn't available in Go 1.17.
 	s := reflect.ValueOf(bi).Elem().FieldByName("Settings")
 	if !s.IsValid() {
 		return false
 	}
 	for i := 0; i < s.Len(); i++ {
 		if s.Index(i).FieldByName("Key").String() == "-race" {
 			return s.Index(i).FieldByName("Value").String() == "true"
 		}
 	}
 	return false
 }
	// Copyright 2019 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 main

	import (
	"archive/tar"
	"archive/zip"
	"bytes"
	"compress/gzip"
	"crypto/sha256"
	"flag"
	"fmt"
	"io"
	"io/fs"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"reflect"
	"regexp"
	"runtime"
	"runtime/debug"
	"strings"
	"sync"
	"testing"
	"time"

	"google.golang.org/protobuf/internal/version"
	)

	var (
	regenerate = flag.Bool("regenerate", false, "regenerate files")
	buildRelease = flag.Bool("buildRelease", false, "build release binaries")

	protobufVersion = "27.0-rc1"

	golangVersions = func() []string {
	// Version policy: same version as is in the x/ repos' go.mod.
	return []string{
	"1.17.13",
	"1.18.10",
	"1.19.13",
	"1.20.12",
	"1.21.5",
	}
	}()
	golangLatest = golangVersions[len(golangVersions)-1]

	staticcheckVersion = "2023.1.6"
	staticcheckSHA256s = map[string]string{
	"darwin/amd64": "b14a0cbd3c238713f5f9db41550893ea7d75d8d7822491c7f4e33e2fe43f6305",
	"darwin/arm64": "f1c869abe6be2c6ab727dc9d6049766c947534766d71a1798c12a37526ea2b6f",
	"linux/386": "02859a7c44c7b5ab41a70d9b8107c01ab8d2c94075bae3d0b02157aff743ca42",
	"linux/amd64": "45337834da5dc7b8eff01cb6b3837e3759503cfbb8edf36b09e42f32bccb1f6e",
	}

	// purgeTimeout determines the maximum age of unused sub-directories.
	purgeTimeout = 30 * 24 * time.Hour // 1 month

	// Variables initialized by mustInitDeps.
	modulePath string
	protobufPath string
	)

	func TestIntegration(t *testing.T) {
	if testing.Short() {
	t.Skip("skipping integration test in short mode")
	}
	if os.Getenv("GO_BUILDER_NAME") != "" {
	// To start off, run on longtest builders, not longtest-race ones.
	if race() {
	t.Skip("skipping integration test in race mode on builders")
	}
	// When on a builder, run even if it's not explicitly requested
	// provided our caller isn't already running it.
	if os.Getenv("GO_PROTOBUF_INTEGRATION_TEST_RUNNING") == "1" {
	t.Skip("protobuf integration test is already running, skipping nested invocation")
	}
	os.Setenv("GO_PROTOBUF_INTEGRATION_TEST_RUNNING", "1")
	} else if flag.Lookup("test.run").Value.String() != "^TestIntegration$" {
	t.Skip("not running integration test if not explicitly requested via test.bash")
	}

	mustInitDeps(t)
	mustHandleFlags(t)

	// Report dirt in the working tree quickly, rather than after
	// going through all the presubmits.
	//
	// Fail the test late, so we can test uncommitted changes with -failfast.
	gitDiff := mustRunCommand(t, "git", "diff", "HEAD")
	if strings.TrimSpace(gitDiff) != "" {
	fmt.Printf("WARNING: working tree contains uncommitted changes:\n%v\n", gitDiff)
	}
	gitUntracked := mustRunCommand(t, "git", "ls-files", "--others", "--exclude-standard")
	if strings.TrimSpace(gitUntracked) != "" {
	fmt.Printf("WARNING: working tree contains untracked files:\n%v\n", gitUntracked)
	}

	// Do the relatively fast checks up-front.
	t.Run("GeneratedGoFiles", func(t *testing.T) {
	diff := mustRunCommand(t, "go", "run", "-tags", "protolegacy", "./internal/cmd/generate-types")
	if strings.TrimSpace(diff) != "" {
	t.Fatalf("stale generated files:\n%v", diff)
	}
	diff = mustRunCommand(t, "go", "run", "-tags", "protolegacy", "./internal/cmd/generate-protos")
	if strings.TrimSpace(diff) != "" {
	t.Fatalf("stale generated files:\n%v", diff)
	}
	})
	t.Run("FormattedGoFiles", func(t *testing.T) {
	files := strings.Split(strings.TrimSpace(mustRunCommand(t, "git", "ls-files", "*.go")), "\n")
	diff := mustRunCommand(t, append([]string{"gofmt", "-d"}, files...)...)
	if strings.TrimSpace(diff) != "" {
	t.Fatalf("unformatted source files:\n%v", diff)
	}
	})
	t.Run("CopyrightHeaders", func(t *testing.T) {
	files := strings.Split(strings.TrimSpace(mustRunCommand(t, "git", "ls-files", ".go", ".proto")), "\n")
	mustHaveCopyrightHeader(t, files)
	})

	var wg sync.WaitGroup
	sema := make(chan bool, (runtime.NumCPU()+1)/2)
	for i := range golangVersions {
	goVersion := golangVersions[i]
	goLabel := "Go" + goVersion
	runGo := func(label string, cmd command, args ...string) {
	wg.Add(1)
	sema <- true
	go func() {
	defer wg.Done()
	defer func() { <-sema }()
	t.Run(goLabel+"/"+label, func(t *testing.T) {
	args[0] += goVersion
	cmd.mustRun(t, args...)
	})
	}()
	}

	runGo("Normal", command{}, "go", "test", "-race", "./...")
	runGo("PureGo", command{}, "go", "test", "-race", "-tags", "purego", "./...")
	runGo("Reflect", command{}, "go", "test", "-race", "-tags", "protoreflect", "./...")
	if goVersion == golangLatest {
	runGo("ProtoLegacyRace", command{}, "go", "test", "-race", "-tags", "protolegacy", "./...")
	runGo("ProtoLegacy", command{}, "go", "test", "-tags", "protolegacy", "./...")
	runGo("ProtocGenGo", command{Dir: "cmd/protoc-gen-go/testdata"}, "go", "test")
	runGo("Conformance", command{Dir: "internal/conformance"}, "go", "test", "-execute")

	// Only run the 32-bit compatibility tests for Linux;
	// avoid Darwin since 10.15 dropped support i386 code execution.
	if runtime.GOOS == "linux" {
	runGo("Arch32Bit", command{Env: append(os.Environ(), "GOARCH=386")}, "go", "test", "./...")
	}
	}
	}
	wg.Wait()

	t.Run("GoStaticCheck", func(t *testing.T) {
	checks := []string{
	"all", // start with all checks enabled
	"-SA1019", // disable deprecated usage check
	"-S*", // disable code simplification checks
	"-ST*", // disable coding style checks
	"-U*", // disable unused declaration checks
	}
	out := mustRunCommand(t, "staticcheck", "-checks="+strings.Join(checks, ","), "-fail=none", "./...")

	// Filter out findings from certain paths.
	var findings []string
	for _, finding := range strings.Split(strings.TrimSpace(out), "\n") {
	switch {
	case strings.HasPrefix(finding, "internal/testprotos/legacy/"):
	default:
	findings = append(findings, finding)
	}
	}
	if len(findings) > 0 {
	t.Fatalf("staticcheck findings:\n%v", strings.Join(findings, "\n"))
	}
	})
	t.Run("CommittedGitChanges", func(t *testing.T) {
	if strings.TrimSpace(gitDiff) != "" {
	t.Fatalf("uncommitted changes")
	}
	})
	t.Run("TrackedGitFiles", func(t *testing.T) {
	if strings.TrimSpace(gitUntracked) != "" {
	t.Fatalf("untracked files")
	}
	})
	}

	func mustInitDeps(t *testing.T) {
	check := func(err error) {
	t.Helper()
	if err != nil {
	t.Fatal(err)
	}
	}

	// Determine the directory to place the test directory.
	repoRoot, err := os.Getwd()
	check(err)
	testDir := filepath.Join(repoRoot, ".cache")
	check(os.MkdirAll(testDir, 0775))

	// Delete the current directory if non-empty,
	// which only occurs if a dependency failed to initialize properly.
	var workingDir string
	finishedDirs := map[string]bool{}
	defer func() {
	if workingDir != "" {
	os.RemoveAll(workingDir) // best-effort
	}
	}()
	startWork := func(name string) string {
	workingDir = filepath.Join(testDir, name)
	return workingDir
	}
	finishWork := func() {
	finishedDirs[workingDir] = true
	workingDir = ""
	}

	// Delete other sub-directories that are no longer relevant.
	defer func() {
	now := time.Now()
	fis, _ := os.ReadDir(testDir)
	for _, fi := range fis {
	dir := filepath.Join(testDir, fi.Name())
	if finishedDirs[dir] {
	os.Chtimes(dir, now, now) // best-effort
	continue
	}
	fii, err := fi.Info()
	check(err)
	if now.Sub(fii.ModTime()) < purgeTimeout {
	continue
	}
	fmt.Printf("delete %v\n", fi.Name())
	os.RemoveAll(dir) // best-effort
	}
	}()

	// The bin directory contains symlinks to each tool by version.
	// It is safe to delete this directory and run the test script from scratch.
	binPath := startWork("bin")
	check(os.RemoveAll(binPath))
	check(os.Mkdir(binPath, 0775))
	check(os.Setenv("PATH", binPath+":"+os.Getenv("PATH")))
	registerBinary := func(name, path string) {
	check(os.Symlink(path, filepath.Join(binPath, name)))
	}
	finishWork()

	// Get the protobuf toolchain.
	protobufPath = startWork("protobuf-" + protobufVersion)
	if _, err := os.Stat(protobufPath); err != nil {
	fmt.Printf("download %v\n", filepath.Base(protobufPath))
	checkoutVersion := protobufVersion
	if isCommit := strings.Trim(protobufVersion, "0123456789abcdef") == ""; !isCommit {
	// release tags have "v" prefix
	checkoutVersion = "v" + protobufVersion
	}
	command{Dir: testDir}.mustRun(t, "git", "clone", "https://github.com/protocolbuffers/protobuf", "protobuf-"+protobufVersion)
	command{Dir: protobufPath}.mustRun(t, "git", "checkout", checkoutVersion)

	if os.Getenv("GO_BUILDER_NAME") != "" {
	// If this is running on the Go build infrastructure,
	// use pre-built versions of these binaries that the
	// builders are configured to provide in $PATH.
	protocPath, err := exec.LookPath("protoc")
	check(err)
	confTestRunnerPath, err := exec.LookPath("conformance_test_runner")
	check(err)
	check(os.MkdirAll(filepath.Join(protobufPath, "bazel-bin", "conformance"), 0775))
	check(os.Symlink(protocPath, filepath.Join(protobufPath, "bazel-bin", "protoc")))
	check(os.Symlink(confTestRunnerPath, filepath.Join(protobufPath, "bazel-bin", "conformance", "conformance_test_runner")))
	} else {
	// In other environments, download and build the protobuf toolchain.
	// We avoid downloading the pre-compiled binaries since they do not contain
	// the conformance test runner.
	fmt.Printf("build %v\n", filepath.Base(protobufPath))
	env := os.Environ()
	args := []string{
	"bazel", "build",
	":protoc",
	"//conformance:conformance_test_runner",
	}
	if runtime.GOOS == "darwin" {
	// Adding this environment variable appears to be necessary for macOS builds.
	env = append(env, "CC=clang")
	// And this flag.
	args = append(args,
	"--macos_minimum_os=13.0",
	"--host_macos_minimum_os=13.0",
	)
	}
	command{
	Dir: protobufPath,
	Env: env,
	}.mustRun(t, args...)
	}
	}
	check(os.Setenv("PROTOBUF_ROOT", protobufPath)) // for generate-protos
	registerBinary("conform-test-runner", filepath.Join(protobufPath, "bazel-bin", "conformance", "conformance_test_runner"))
	registerBinary("protoc", filepath.Join(protobufPath, "bazel-bin", "protoc"))
	finishWork()

	// Download each Go toolchain version.
	for _, v := range golangVersions {
	goDir := startWork("go" + v)
	if _, err := os.Stat(goDir); err != nil {
	fmt.Printf("download %v\n", filepath.Base(goDir))
	url := fmt.Sprintf("https://dl.google.com/go/go%v.%v-%v.tar.gz", v, runtime.GOOS, runtime.GOARCH)
	downloadArchive(check, goDir, url, "go", "") // skip SHA256 check as we fetch over https from a trusted domain
	}
	registerBinary("go"+v, filepath.Join(goDir, "bin", "go"))
	finishWork()
	}
	registerBinary("go", filepath.Join(testDir, "go"+golangLatest, "bin", "go"))
	registerBinary("gofmt", filepath.Join(testDir, "go"+golangLatest, "bin", "gofmt"))

	// Download the staticcheck tool.
	checkDir := startWork("staticcheck-" + staticcheckVersion)
	if _, err := os.Stat(checkDir); err != nil {
	fmt.Printf("download %v\n", filepath.Base(checkDir))
	url := fmt.Sprintf("https://github.com/dominikh/go-tools/releases/download/%v/staticcheck_%v_%v.tar.gz", staticcheckVersion, runtime.GOOS, runtime.GOARCH)
	downloadArchive(check, checkDir, url, "staticcheck", staticcheckSHA256s[runtime.GOOS+"/"+runtime.GOARCH])
	}
	registerBinary("staticcheck", filepath.Join(checkDir, "staticcheck"))
	finishWork()

	// GitHub actions sets GOROOT, which confuses invocations of the Go toolchain.
	// Explicitly clear GOROOT, so each toolchain uses their default GOROOT.
	check(os.Unsetenv("GOROOT"))

	// Set a cache directory outside the test directory.
	check(os.Setenv("GOCACHE", filepath.Join(repoRoot, ".gocache")))
	}

	func downloadFile(check func(error), dstPath, srcURL string, perm fs.FileMode) {
	resp, err := http.Get(srcURL)
	check(err)
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
	body, _ := io.ReadAll(io.LimitReader(resp.Body, 4<<10))
	check(fmt.Errorf("GET %q: non-200 OK status code: %v body: %q", srcURL, resp.Status, body))
	}

	check(os.MkdirAll(filepath.Dir(dstPath), 0775))
	f, err := os.OpenFile(dstPath, os.O_WRONLY\|os.O_CREATE\|os.O_TRUNC, perm)
	check(err)

	_, err = io.Copy(f, resp.Body)
	check(err)

	check(f.Close())
	}

	func downloadArchive(check func(error), dstPath, srcURL, skipPrefix, wantSHA256 string) {
	check(os.RemoveAll(dstPath))

	resp, err := http.Get(srcURL)
	check(err)
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
	body, _ := io.ReadAll(io.LimitReader(resp.Body, 4<<10))
	check(fmt.Errorf("GET %q: non-200 OK status code: %v body: %q", srcURL, resp.Status, body))
	}

	var r io.Reader = resp.Body
	if wantSHA256 != "" {
	b, err := io.ReadAll(resp.Body)
	check(err)
	r = bytes.NewReader(b)

	if gotSHA256 := fmt.Sprintf("%x", sha256.Sum256(b)); gotSHA256 != wantSHA256 {
	check(fmt.Errorf("checksum validation error:\ngot %v\nwant %v", gotSHA256, wantSHA256))
	}
	}

	zr, err := gzip.NewReader(r)
	check(err)

	tr := tar.NewReader(zr)
	for {
	h, err := tr.Next()
	if err == io.EOF {
	return
	}
	check(err)

	// Skip directories or files outside the prefix directory.
	if len(skipPrefix) > 0 {
	if !strings.HasPrefix(h.Name, skipPrefix) {
	continue
	}
	if len(h.Name) > len(skipPrefix) && h.Name[len(skipPrefix)] != '/' {
	continue
	}
	}

	path := strings.TrimPrefix(strings.TrimPrefix(h.Name, skipPrefix), "/")
	path = filepath.Join(dstPath, filepath.FromSlash(path))
	mode := os.FileMode(h.Mode & 0777)
	switch h.Typeflag {
	case tar.TypeReg:
	b, err := io.ReadAll(tr)
	check(err)
	check(os.WriteFile(path, b, mode))
	case tar.TypeDir:
	check(os.Mkdir(path, mode))
	}
	}
	}

	func mustHandleFlags(t *testing.T) {
	if *regenerate {
	t.Run("Generate", func(t *testing.T) {
	fmt.Print(mustRunCommand(t, "go", "generate", "./internal/cmd/generate-types"))
	fmt.Print(mustRunCommand(t, "go", "generate", "./internal/cmd/generate-protos"))
	files := strings.Split(strings.TrimSpace(mustRunCommand(t, "git", "ls-files", "*.go")), "\n")
	mustRunCommand(t, append([]string{"gofmt", "-w"}, files...)...)
	})
	}
	if *buildRelease {
	t.Run("BuildRelease", func(t *testing.T) {
	v := version.String()
	for _, goos := range []string{"linux", "darwin", "windows"} {
	for _, goarch := range []string{"386", "amd64", "arm64"} {
	// Avoid Darwin since 10.15 dropped support for i386.
	if goos == "darwin" && goarch == "386" {
	continue
	}

	binPath := filepath.Join("bin", fmt.Sprintf("protoc-gen-go.%v.%v.%v", v, goos, goarch))

	// Build the binary.
	cmd := command{Env: append(os.Environ(), "GOOS="+goos, "GOARCH="+goarch)}
	cmd.mustRun(t, "go", "build", "-trimpath", "-ldflags", "-s -w -buildid=", "-o", binPath, "./cmd/protoc-gen-go")

	// Archive and compress the binary.
	in, err := os.ReadFile(binPath)
	if err != nil {
	t.Fatal(err)
	}
	out := new(bytes.Buffer)
	suffix := ""
	comment := fmt.Sprintf("protoc-gen-go VERSION=%v GOOS=%v GOARCH=%v", v, goos, goarch)
	switch goos {
	case "windows":
	suffix = ".zip"
	zw := zip.NewWriter(out)
	zw.SetComment(comment)
	fw, _ := zw.Create("protoc-gen-go.exe")
	fw.Write(in)
	zw.Close()
	default:
	suffix = ".tar.gz"
	gz, _ := gzip.NewWriterLevel(out, gzip.BestCompression)
	gz.Comment = comment
	tw := tar.NewWriter(gz)
	tw.WriteHeader(&tar.Header{
	Name: "protoc-gen-go",
	Mode: int64(0775),
	Size: int64(len(in)),
	})
	tw.Write(in)
	tw.Close()
	gz.Close()
	}
	if err := os.WriteFile(binPath+suffix, out.Bytes(), 0664); err != nil {
	t.Fatal(err)
	}
	}
	}
	})
	}
	if regenerate \|\| buildRelease {
	t.SkipNow()
	}
	}

	var copyrightRegex = []*regexp.Regexp{
	regexp.MustCompile(`^// Copyright \d\d\d\d 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\.
	`),
	// Generated .pb.go files from main protobuf repo.
	regexp.MustCompile(`^// Protocol Buffers - Google's data interchange format
	// Copyright \d\d\d\d Google Inc\. All rights reserved\.
	`),
	}

	func mustHaveCopyrightHeader(t *testing.T, files []string) {
	var bad []string
	File:
	for _, file := range files {
	if strings.HasSuffix(file, "internal/testprotos/conformance/editions/test_messages_edition2023.pb.go") {
	// TODO(lassefolger) the underlying proto file is checked into
	// the protobuf repo without a copyright header. Fix is pending but
	// might require a release.
	continue
	}
	b, err := os.ReadFile(file)
	if err != nil {
	t.Fatal(err)
	}
	for _, re := range copyrightRegex {
	if loc := re.FindIndex(b); loc != nil && loc[0] == 0 {
	continue File
	}
	}
	bad = append(bad, file)
	}
	if len(bad) > 0 {
	t.Fatalf("files with missing/bad copyright headers:\n %v", strings.Join(bad, "\n "))
	}
	}

	type command struct {
	Dir string
	Env []string
	}

	func (c command) mustRun(t *testing.T, args ...string) string {
	t.Helper()
	stdout := new(bytes.Buffer)
	stderr := new(bytes.Buffer)
	cmd := exec.Command(args[0], args[1:]...)
	cmd.Dir = "."
	if c.Dir != "" {
	cmd.Dir = c.Dir
	}
	cmd.Env = os.Environ()
	if c.Env != nil {
	cmd.Env = c.Env
	}
	cmd.Env = append(cmd.Env, "PWD="+cmd.Dir)
	cmd.Stdout = stdout
	cmd.Stderr = stderr
	if err := cmd.Run(); err != nil {
	t.Fatalf("executing (%v): %v\n%s%s", strings.Join(args, " "), err, stdout.String(), stderr.String())
	}
	return stdout.String()
	}

	func mustRunCommand(t *testing.T, args ...string) string {
	t.Helper()
	return command{}.mustRun(t, args...)
	}

	// race is an approximation of whether the race detector is on.
	// It's used to skip the integration test on builders, without
	// preventing the integration test from running under the race
	// detector as a '//go:build !race' build constraint would.
	func race() bool {
	bi, ok := debug.ReadBuildInfo()
	if !ok {
	return false
	}
	// Use reflect because the debug.BuildInfo.Settings field
	// isn't available in Go 1.17.
	s := reflect.ValueOf(bi).Elem().FieldByName("Settings")
	if !s.IsValid() {
	return false
	}
	for i := 0; i < s.Len(); i++ {
	if s.Index(i).FieldByName("Key").String() == "-race" {
	return s.Index(i).FieldByName("Value").String() == "true"
	}
	}
	return false
	}