testenv.go

Documentation: golang.org/x/tools/internal/testenv

     1  // Copyright 2019 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package testenv contains helper functions for skipping tests
     6  // based on which tools are present in the environment.
     7  package testenv
     8  
     9  import (
    10  	"bytes"
    11  	"fmt"
    12  	"go/build"
    13  	"os"
    14  	"os/exec"
    15  	"path/filepath"
    16  	"runtime"
    17  	"runtime/debug"
    18  	"strings"
    19  	"sync"
    20  	"testing"
    21  	"time"
    22  
    23  	"golang.org/x/mod/modfile"
    24  	"golang.org/x/tools/internal/goroot"
    25  )
    26  
    27  // packageMainIsDevel reports whether the module containing package main
    28  // is a development version (if module information is available).
    29  func packageMainIsDevel() bool {
    30  	info, ok := debug.ReadBuildInfo()
    31  	if !ok {
    32  		// Most test binaries currently lack build info, but this should become more
    33  		// permissive once https://golang.org/issue/33976 is fixed.
    34  		return true
    35  	}
    36  
    37  	// Note: info.Main.Version describes the version of the module containing
    38  	// package main, not the version of “the main module”.
    39  	// See https://golang.org/issue/33975.
    40  	return info.Main.Version == "(devel)"
    41  }
    42  
    43  var checkGoBuild struct {
    44  	once sync.Once
    45  	err  error
    46  }
    47  
    48  // HasTool reports an error if the required tool is not available in PATH.
    49  //
    50  // For certain tools, it checks that the tool executable is correct.
    51  func HasTool(tool string) error {
    52  	if tool == "cgo" {
    53  		enabled, err := cgoEnabled(false)
    54  		if err != nil {
    55  			return fmt.Errorf("checking cgo: %v", err)
    56  		}
    57  		if !enabled {
    58  			return fmt.Errorf("cgo not enabled")
    59  		}
    60  		return nil
    61  	}
    62  
    63  	_, err := exec.LookPath(tool)
    64  	if err != nil {
    65  		return err
    66  	}
    67  
    68  	switch tool {
    69  	case "patch":
    70  		// check that the patch tools supports the -o argument
    71  		temp, err := os.CreateTemp("", "patch-test")
    72  		if err != nil {
    73  			return err
    74  		}
    75  		temp.Close()
    76  		defer os.Remove(temp.Name())
    77  		cmd := exec.Command(tool, "-o", temp.Name())
    78  		if err := cmd.Run(); err != nil {
    79  			return err
    80  		}
    81  
    82  	case "go":
    83  		checkGoBuild.once.Do(func() {
    84  			if runtime.GOROOT() != "" {
    85  				// Ensure that the 'go' command found by exec.LookPath is from the correct
    86  				// GOROOT. Otherwise, 'some/path/go test ./...' will test against some
    87  				// version of the 'go' binary other than 'some/path/go', which is almost
    88  				// certainly not what the user intended.
    89  				out, err := exec.Command(tool, "env", "GOROOT").Output()
    90  				if err != nil {
    91  					if exit, ok := err.(*exec.ExitError); ok && len(exit.Stderr) > 0 {
    92  						err = fmt.Errorf("%w\nstderr:\n%s)", err, exit.Stderr)
    93  					}
    94  					checkGoBuild.err = err
    95  					return
    96  				}
    97  				GOROOT := strings.TrimSpace(string(out))
    98  				if GOROOT != runtime.GOROOT() {
    99  					checkGoBuild.err = fmt.Errorf("'go env GOROOT' does not match runtime.GOROOT:\n\tgo env: %s\n\tGOROOT: %s", GOROOT, runtime.GOROOT())
   100  					return
   101  				}
   102  			}
   103  
   104  			dir, err := os.MkdirTemp("", "testenv-*")
   105  			if err != nil {
   106  				checkGoBuild.err = err
   107  				return
   108  			}
   109  			defer os.RemoveAll(dir)
   110  
   111  			mainGo := filepath.Join(dir, "main.go")
   112  			if err := os.WriteFile(mainGo, []byte("package main\nfunc main() {}\n"), 0644); err != nil {
   113  				checkGoBuild.err = err
   114  				return
   115  			}
   116  			cmd := exec.Command("go", "build", "-o", os.DevNull, mainGo)
   117  			cmd.Dir = dir
   118  			if out, err := cmd.CombinedOutput(); err != nil {
   119  				if len(out) > 0 {
   120  					checkGoBuild.err = fmt.Errorf("%v: %v\n%s", cmd, err, out)
   121  				} else {
   122  					checkGoBuild.err = fmt.Errorf("%v: %v", cmd, err)
   123  				}
   124  			}
   125  		})
   126  		if checkGoBuild.err != nil {
   127  			return checkGoBuild.err
   128  		}
   129  
   130  	case "diff":
   131  		// Check that diff is the GNU version, needed for the -u argument and
   132  		// to report missing newlines at the end of files.
   133  		out, err := exec.Command(tool, "-version").Output()
   134  		if err != nil {
   135  			return err
   136  		}
   137  		if !bytes.Contains(out, []byte("GNU diffutils")) {
   138  			return fmt.Errorf("diff is not the GNU version")
   139  		}
   140  	}
   141  
   142  	return nil
   143  }
   144  
   145  func cgoEnabled(bypassEnvironment bool) (bool, error) {
   146  	cmd := exec.Command("go", "env", "CGO_ENABLED")
   147  	if bypassEnvironment {
   148  		cmd.Env = append(append([]string(nil), os.Environ()...), "CGO_ENABLED=")
   149  	}
   150  	out, err := cmd.Output()
   151  	if err != nil {
   152  		if exit, ok := err.(*exec.ExitError); ok && len(exit.Stderr) > 0 {
   153  			err = fmt.Errorf("%w\nstderr:\n%s", err, exit.Stderr)
   154  		}
   155  		return false, err
   156  	}
   157  	enabled := strings.TrimSpace(string(out))
   158  	return enabled == "1", nil
   159  }
   160  
   161  func allowMissingTool(tool string) bool {
   162  	switch runtime.GOOS {
   163  	case "aix", "darwin", "dragonfly", "freebsd", "illumos", "linux", "netbsd", "openbsd", "plan9", "solaris", "windows":
   164  		// Known non-mobile OS. Expect a reasonably complete environment.
   165  	default:
   166  		return true
   167  	}
   168  
   169  	switch tool {
   170  	case "cgo":
   171  		if strings.HasSuffix(os.Getenv("GO_BUILDER_NAME"), "-nocgo") {
   172  			// Explicitly disabled on -nocgo builders.
   173  			return true
   174  		}
   175  		if enabled, err := cgoEnabled(true); err == nil && !enabled {
   176  			// No platform support.
   177  			return true
   178  		}
   179  	case "go":
   180  		if os.Getenv("GO_BUILDER_NAME") == "illumos-amd64-joyent" {
   181  			// Work around a misconfigured builder (see https://golang.org/issue/33950).
   182  			return true
   183  		}
   184  	case "diff":
   185  		if os.Getenv("GO_BUILDER_NAME") != "" {
   186  			return true
   187  		}
   188  	case "patch":
   189  		if os.Getenv("GO_BUILDER_NAME") != "" {
   190  			return true
   191  		}
   192  	}
   193  
   194  	// If a developer is actively working on this test, we expect them to have all
   195  	// of its dependencies installed. However, if it's just a dependency of some
   196  	// other module (for example, being run via 'go test all'), we should be more
   197  	// tolerant of unusual environments.
   198  	return !packageMainIsDevel()
   199  }
   200  
   201  // NeedsTool skips t if the named tool is not present in the path.
   202  // As a special case, "cgo" means "go" is present and can compile cgo programs.
   203  func NeedsTool(t testing.TB, tool string) {
   204  	err := HasTool(tool)
   205  	if err == nil {
   206  		return
   207  	}
   208  
   209  	t.Helper()
   210  	if allowMissingTool(tool) {
   211  		// TODO(adonovan): if we skip because of (e.g.)
   212  		// mismatched go env GOROOT and runtime.GOROOT, don't
   213  		// we risk some users not getting the coverage they expect?
   214  		// bcmills notes: this shouldn't be a concern as of CL 404134 (Go 1.19).
   215  		// We could probably safely get rid of that GOPATH consistency
   216  		// check entirely at this point.
   217  		t.Skipf("skipping because %s tool not available: %v", tool, err)
   218  	} else {
   219  		t.Fatalf("%s tool not available: %v", tool, err)
   220  	}
   221  }
   222  
   223  // NeedsGoPackages skips t if the go/packages driver (or 'go' tool) implied by
   224  // the current process environment is not present in the path.
   225  func NeedsGoPackages(t testing.TB) {
   226  	t.Helper()
   227  
   228  	tool := os.Getenv("GOPACKAGESDRIVER")
   229  	switch tool {
   230  	case "off":
   231  		// "off" forces go/packages to use the go command.
   232  		tool = "go"
   233  	case "":
   234  		if _, err := exec.LookPath("gopackagesdriver"); err == nil {
   235  			tool = "gopackagesdriver"
   236  		} else {
   237  			tool = "go"
   238  		}
   239  	}
   240  
   241  	NeedsTool(t, tool)
   242  }
   243  
   244  // NeedsGoPackagesEnv skips t if the go/packages driver (or 'go' tool) implied
   245  // by env is not present in the path.
   246  func NeedsGoPackagesEnv(t testing.TB, env []string) {
   247  	t.Helper()
   248  
   249  	for _, v := range env {
   250  		if strings.HasPrefix(v, "GOPACKAGESDRIVER=") {
   251  			tool := strings.TrimPrefix(v, "GOPACKAGESDRIVER=")
   252  			if tool == "off" {
   253  				NeedsTool(t, "go")
   254  			} else {
   255  				NeedsTool(t, tool)
   256  			}
   257  			return
   258  		}
   259  	}
   260  
   261  	NeedsGoPackages(t)
   262  }
   263  
   264  // NeedsGoBuild skips t if the current system can't build programs with “go build”
   265  // and then run them with os.StartProcess or exec.Command.
   266  // Android doesn't have the userspace go build needs to run,
   267  // and js/wasm doesn't support running subprocesses.
   268  func NeedsGoBuild(t testing.TB) {
   269  	t.Helper()
   270  
   271  	// This logic was derived from internal/testing.HasGoBuild and
   272  	// may need to be updated as that function evolves.
   273  
   274  	NeedsTool(t, "go")
   275  }
   276  
   277  // ExitIfSmallMachine emits a helpful diagnostic and calls os.Exit(0) if the
   278  // current machine is a builder known to have scarce resources.
   279  //
   280  // It should be called from within a TestMain function.
   281  func ExitIfSmallMachine() {
   282  	switch b := os.Getenv("GO_BUILDER_NAME"); b {
   283  	case "linux-arm-scaleway":
   284  		// "linux-arm" was renamed to "linux-arm-scaleway" in CL 303230.
   285  		fmt.Fprintln(os.Stderr, "skipping test: linux-arm-scaleway builder lacks sufficient memory (https://golang.org/issue/32834)")
   286  	case "plan9-arm":
   287  		fmt.Fprintln(os.Stderr, "skipping test: plan9-arm builder lacks sufficient memory (https://golang.org/issue/38772)")
   288  	case "netbsd-arm-bsiegert", "netbsd-arm64-bsiegert":
   289  		// As of 2021-06-02, these builders are running with GO_TEST_TIMEOUT_SCALE=10,
   290  		// and there is only one of each. We shouldn't waste those scarce resources
   291  		// running very slow tests.
   292  		fmt.Fprintf(os.Stderr, "skipping test: %s builder is very slow\n", b)
   293  	case "dragonfly-amd64":
   294  		// As of 2021-11-02, this builder is running with GO_TEST_TIMEOUT_SCALE=2,
   295  		// and seems to have unusually slow disk performance.
   296  		fmt.Fprintln(os.Stderr, "skipping test: dragonfly-amd64 has slow disk (https://golang.org/issue/45216)")
   297  	case "linux-riscv64-unmatched":
   298  		// As of 2021-11-03, this builder is empirically not fast enough to run
   299  		// gopls tests. Ideally we should make the tests faster in short mode
   300  		// and/or fix them to not assume arbitrary deadlines.
   301  		// For now, we'll skip them instead.
   302  		fmt.Fprintf(os.Stderr, "skipping test: %s builder is too slow (https://golang.org/issue/49321)\n", b)
   303  	default:
   304  		switch runtime.GOOS {
   305  		case "android", "ios":
   306  			fmt.Fprintf(os.Stderr, "skipping test: assuming that %s is resource-constrained\n", runtime.GOOS)
   307  		default:
   308  			return
   309  		}
   310  	}
   311  	os.Exit(0)
   312  }
   313  
   314  // Go1Point returns the x in Go 1.x.
   315  func Go1Point() int {
   316  	for i := len(build.Default.ReleaseTags) - 1; i >= 0; i-- {
   317  		var version int
   318  		if _, err := fmt.Sscanf(build.Default.ReleaseTags[i], "go1.%d", &version); err != nil {
   319  			continue
   320  		}
   321  		return version
   322  	}
   323  	panic("bad release tags")
   324  }
   325  
   326  // NeedsGo1Point skips t if the Go version used to run the test is older than
   327  // 1.x.
   328  func NeedsGo1Point(t testing.TB, x int) {
   329  	if Go1Point() < x {
   330  		t.Helper()
   331  		t.Skipf("running Go version %q is version 1.%d, older than required 1.%d", runtime.Version(), Go1Point(), x)
   332  	}
   333  }
   334  
   335  // SkipAfterGo1Point skips t if the Go version used to run the test is newer than
   336  // 1.x.
   337  func SkipAfterGo1Point(t testing.TB, x int) {
   338  	if Go1Point() > x {
   339  		t.Helper()
   340  		t.Skipf("running Go version %q is version 1.%d, newer than maximum 1.%d", runtime.Version(), Go1Point(), x)
   341  	}
   342  }
   343  
   344  // NeedsLocalhostNet skips t if networking does not work for ports opened
   345  // with "localhost".
   346  func NeedsLocalhostNet(t testing.TB) {
   347  	switch runtime.GOOS {
   348  	case "js", "wasip1":
   349  		t.Skipf(`Listening on "localhost" fails on %s; see https://go.dev/issue/59718`, runtime.GOOS)
   350  	}
   351  }
   352  
   353  // Deadline returns the deadline of t, if known,
   354  // using the Deadline method added in Go 1.15.
   355  func Deadline(t testing.TB) (time.Time, bool) {
   356  	td, ok := t.(interface {
   357  		Deadline() (time.Time, bool)
   358  	})
   359  	if !ok {
   360  		return time.Time{}, false
   361  	}
   362  	return td.Deadline()
   363  }
   364  
   365  // WriteImportcfg writes an importcfg file used by the compiler or linker to
   366  // dstPath containing entries for the packages in std and cmd in addition
   367  // to the package to package file mappings in additionalPackageFiles.
   368  func WriteImportcfg(t testing.TB, dstPath string, additionalPackageFiles map[string]string) {
   369  	importcfg, err := goroot.Importcfg()
   370  	for k, v := range additionalPackageFiles {
   371  		importcfg += fmt.Sprintf("\npackagefile %s=%s", k, v)
   372  	}
   373  	if err != nil {
   374  		t.Fatalf("preparing the importcfg failed: %s", err)
   375  	}
   376  	os.WriteFile(dstPath, []byte(importcfg), 0655)
   377  	if err != nil {
   378  		t.Fatalf("writing the importcfg failed: %s", err)
   379  	}
   380  }
   381  
   382  var (
   383  	gorootOnce sync.Once
   384  	gorootPath string
   385  	gorootErr  error
   386  )
   387  
   388  func findGOROOT() (string, error) {
   389  	gorootOnce.Do(func() {
   390  		gorootPath = runtime.GOROOT()
   391  		if gorootPath != "" {
   392  			// If runtime.GOROOT() is non-empty, assume that it is valid. (It might
   393  			// not be: for example, the user may have explicitly set GOROOT
   394  			// to the wrong directory.)
   395  			return
   396  		}
   397  
   398  		cmd := exec.Command("go", "env", "GOROOT")
   399  		out, err := cmd.Output()
   400  		if err != nil {
   401  			gorootErr = fmt.Errorf("%v: %v", cmd, err)
   402  		}
   403  		gorootPath = strings.TrimSpace(string(out))
   404  	})
   405  
   406  	return gorootPath, gorootErr
   407  }
   408  
   409  // GOROOT reports the path to the directory containing the root of the Go
   410  // project source tree. This is normally equivalent to runtime.GOROOT, but
   411  // works even if the test binary was built with -trimpath.
   412  //
   413  // If GOROOT cannot be found, GOROOT skips t if t is non-nil,
   414  // or panics otherwise.
   415  func GOROOT(t testing.TB) string {
   416  	path, err := findGOROOT()
   417  	if err != nil {
   418  		if t == nil {
   419  			panic(err)
   420  		}
   421  		t.Helper()
   422  		t.Skip(err)
   423  	}
   424  	return path
   425  }
   426  
   427  // NeedsLocalXTools skips t if the golang.org/x/tools module is replaced and
   428  // its replacement directory does not exist (or does not contain the module).
   429  func NeedsLocalXTools(t testing.TB) {
   430  	t.Helper()
   431  
   432  	NeedsTool(t, "go")
   433  
   434  	cmd := Command(t, "go", "list", "-f", "{{with .Replace}}{{.Dir}}{{end}}", "-m", "golang.org/x/tools")
   435  	out, err := cmd.Output()
   436  	if err != nil {
   437  		if ee, ok := err.(*exec.ExitError); ok && len(ee.Stderr) > 0 {
   438  			t.Skipf("skipping test: %v: %v\n%s", cmd, err, ee.Stderr)
   439  		}
   440  		t.Skipf("skipping test: %v: %v", cmd, err)
   441  	}
   442  
   443  	dir := string(bytes.TrimSpace(out))
   444  	if dir == "" {
   445  		// No replacement directory, and (since we didn't set -e) no error either.
   446  		// Maybe x/tools isn't replaced at all (as in a gopls release, or when
   447  		// using a go.work file that includes the x/tools module).
   448  		return
   449  	}
   450  
   451  	// We found the directory where x/tools would exist if we're in a clone of the
   452  	// repo. Is it there? (If not, we're probably in the module cache instead.)
   453  	modFilePath := filepath.Join(dir, "go.mod")
   454  	b, err := os.ReadFile(modFilePath)
   455  	if err != nil {
   456  		t.Skipf("skipping test: x/tools replacement not found: %v", err)
   457  	}
   458  	modulePath := modfile.ModulePath(b)
   459  
   460  	if want := "golang.org/x/tools"; modulePath != want {
   461  		t.Skipf("skipping test: %s module path is %q, not %q", modFilePath, modulePath, want)
   462  	}
   463  }
   464  
   465  // NeedsGoExperiment skips t if the current process environment does not
   466  // have a GOEXPERIMENT flag set.
   467  func NeedsGoExperiment(t testing.TB, flag string) {
   468  	t.Helper()
   469  
   470  	goexp := os.Getenv("GOEXPERIMENT")
   471  	set := false
   472  	for _, f := range strings.Split(goexp, ",") {
   473  		if f == "" {
   474  			continue
   475  		}
   476  		if f == "none" {
   477  			// GOEXPERIMENT=none disables all experiment flags.
   478  			set = false
   479  			break
   480  		}
   481  		val := true
   482  		if strings.HasPrefix(f, "no") {
   483  			f, val = f[2:], false
   484  		}
   485  		if f == flag {
   486  			set = val
   487  		}
   488  	}
   489  	if !set {
   490  		t.Skipf("skipping test: flag %q is not set in GOEXPERIMENT=%q", flag, goexp)
   491  	}
   492  }
   493
View as plain text