cmd/stringer/endtoend_test.go - tools.git - Git at Google

 // Copyright 2014 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.

 // go command is not available on android

 //go:build !android

 package main

 import (
 	"bytes"
 	"flag"
 	"fmt"
 	"io"
 	"os"
 	"path"
 	"path/filepath"
 	"reflect"
 	"slices"
 	"strings"
 	"sync"
 	"testing"

 	"golang.org/x/tools/internal/testenv"
 )

 // This file contains a test that compiles and runs each program in testdata
 // after generating the string method for its type. The rule is that for testdata/x.go
 // we run stringer -type X and then compile and run the program. The resulting
 // binary panics if the String method for X is not correct, including for error cases.

 func TestMain(m *testing.M) {
 	if os.Getenv("STRINGER_TEST_IS_STRINGER") != "" {
 		main()
 		os.Exit(0)
 	}

 	// Inform subprocesses that they should run the cmd/stringer main instead of
 	// running tests. It's a close approximation to building and running the real
 	// command, and much less complicated and expensive to build and clean up.
 	os.Setenv("STRINGER_TEST_IS_STRINGER", "1")

 	flag.Parse()
 	if testing.Verbose() {
 		os.Setenv("GOPACKAGESDEBUG", "true")
 	}

 	os.Exit(m.Run())
 }

 func TestEndToEnd(t *testing.T) {
 	testenv.NeedsTool(t, "go")

 	stringer := stringerPath(t)
 	// Read the testdata directory.
 	fd, err := os.Open("testdata")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer fd.Close()
 	names, err := fd.Readdirnames(-1)
 	if err != nil {
 		t.Fatalf("Readdirnames: %s", err)
 	}
 	// Generate, compile, and run the test programs.
 	for _, name := range names {
 		if name == "typeparams" {
 			// ignore the directory containing the tests with type params
 			continue
 		}
 		if !strings.HasSuffix(name, ".go") {
 			t.Errorf("%s is not a Go file", name)
 			continue
 		}
 		if strings.HasPrefix(name, "tag_") || strings.HasPrefix(name, "vary_") {
 			// This file is used for tag processing in TestTags or TestConstValueChange, below.
 			continue
 		}
 		t.Run(name, func(t *testing.T) {
 			if name == "cgo.go" {
 				testenv.NeedsTool(t, "cgo")
 			}
 			stringerCompileAndRun(t, t.TempDir(), stringer, typeName(name), name)
 		})
 	}
 }

 // a type name for stringer. use the last component of the file name with the .go
 func typeName(fname string) string {
 	// file names are known to be ascii and end .go
 	base := path.Base(fname)
 	return fmt.Sprintf("%c%s", base[0]+'A'-'a', base[1:len(base)-len(".go")])
 }

 // TestTags verifies that the -tags flag works as advertised.
 func TestTags(t *testing.T) {
 	stringer := stringerPath(t)
 	dir := t.TempDir()
 	var (
 		protectedConst = []byte("TagProtected")
 		output         = filepath.Join(dir, "const_string.go")
 	)
 	for _, file := range []string{"tag_main.go", "tag_tag.go"} {
 		err := copy(filepath.Join(dir, file), filepath.Join("testdata", file))
 		if err != nil {
 			t.Fatal(err)
 		}
 	}
 	// Run stringer in the directory that contains the module that contains the package files.
 	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module test\n"), 0o600); err != nil {
 		t.Fatal(err)
 	}
 	err := runInDir(t, dir, stringer, "-type", "Const", ".")
 	if err != nil {
 		t.Fatal(err)
 	}
 	result, err := os.ReadFile(output)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if bytes.Contains(result, protectedConst) {
 		t.Fatal("tagged variable appears in untagged run")
 	}
 	err = os.Remove(output)
 	if err != nil {
 		t.Fatal(err)
 	}
 	err = runInDir(t, dir, stringer, "-type", "Const", "-tags", "tag", ".")
 	if err != nil {
 		t.Fatal(err)
 	}
 	result, err = os.ReadFile(output)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if !bytes.Contains(result, protectedConst) {
 		t.Fatal("tagged variable does not appear in tagged run")
 	}
 }

 // TestConstValueChange verifies that if a constant value changes and
 // the stringer code is not regenerated, we'll get a compiler error.
 func TestConstValueChange(t *testing.T) {
 	testenv.NeedsTool(t, "go")

 	stringer := stringerPath(t)
 	dir := t.TempDir()
 	source := filepath.Join(dir, "day.go")
 	err := copy(source, filepath.Join("testdata", "day.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
 	stringSource := filepath.Join(dir, "day_string.go")
 	// Run stringer in the directory that contains the module that contains the package files.
 	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module test\n"), 0o600); err != nil {
 		t.Fatal(err)
 	}
 	err = runInDir(t, dir, stringer, "-type", "Day", "-output", stringSource)
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Run the binary in the temporary directory as a sanity check.
 	err = run(t, "go", "run", stringSource, source)
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Overwrite the source file with a version that has changed constants.
 	err = copy(source, filepath.Join("testdata", "vary_day.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Unfortunately different compilers may give different error messages,
 	// so there's no easy way to verify that the build failed specifically
 	// because the constants changed rather than because the vary_day.go
 	// file is invalid.
 	//
 	// Instead we'll just rely on manual inspection of the polluted test
 	// output. An alternative might be to check that the error output
 	// matches a set of possible error strings emitted by known
 	// Go compilers.
 	t.Logf("Note: the following messages should indicate an out-of-bounds compiler error\n")
 	err = run(t, "go", "build", stringSource, source)
 	if err == nil {
 		t.Fatal("unexpected compiler success")
 	}
 }

 var testfileSrcs = map[string]string{
 	"go.mod": "module foo",

 	// Normal file in the package.
 	"main.go": `package foo

 type Foo int

 const (
 	fooX Foo = iota
 	fooY
 	fooZ
 )
 `,

 	// Test file in the package.
 	"main_test.go": `package foo

 type Bar int

 const (
 	barX Bar = iota
 	barY
 	barZ
 )
 `,

 	// Test file in the test package.
 	"main_pkg_test.go": `package foo_test

 type Baz int

 const (
 	bazX Baz = iota
 	bazY
 	bazZ
 )
 `,
 }

 // Test stringer on types defined in different kinds of tests.
 // The generated code should not interfere between itself.
 func TestTestFiles(t *testing.T) {
 	testenv.NeedsTool(t, "go")
 	stringer := stringerPath(t)

 	dir := t.TempDir()
 	t.Logf("TestTestFiles in: %s \n", dir)
 	for name, src := range testfileSrcs {
 		source := filepath.Join(dir, name)
 		err := os.WriteFile(source, []byte(src), 0666)
 		if err != nil {
 			t.Fatalf("write file: %s", err)
 		}
 	}

 	// Must run stringer in the temp directory, see TestTags.
 	err := runInDir(t, dir, stringer, "-type=Foo,Bar,Baz", dir)
 	if err != nil {
 		t.Fatalf("run stringer: %s", err)
 	}

 	// Check that stringer has created the expected files.
 	content, err := os.ReadDir(dir)
 	if err != nil {
 		t.Fatalf("read dir: %s", err)
 	}
 	gotFiles := []string{}
 	for _, f := range content {
 		if !f.IsDir() {
 			gotFiles = append(gotFiles, f.Name())
 		}
 	}
 	wantFiles := []string{
 		// Original.
 		"go.mod",
 		"main.go",
 		"main_test.go",
 		"main_pkg_test.go",
 		// Generated.
 		"foo_string.go",
 		"bar_string_test.go",
 		"baz_string_test.go",
 	}
 	slices.Sort(gotFiles)
 	slices.Sort(wantFiles)
 	if !reflect.DeepEqual(gotFiles, wantFiles) {
 		t.Errorf("stringer generated files:\n%s\n\nbut want:\n%s",
 			strings.Join(gotFiles, "\n"),
 			strings.Join(wantFiles, "\n"),
 		)
 	}

 	// Run go test as a smoke test.
 	err = runInDir(t, dir, "go", "test", "-count=1", ".")
 	if err != nil {
 		t.Fatalf("go test: %s", err)
 	}
 }

 // The -output flag cannot be used in combiation with matching types across multiple packages.
 func TestCollidingOutput(t *testing.T) {
 	testenv.NeedsTool(t, "go")
 	stringer := stringerPath(t)

 	dir := t.TempDir()
 	for name, src := range testfileSrcs {
 		source := filepath.Join(dir, name)
 		err := os.WriteFile(source, []byte(src), 0666)
 		if err != nil {
 			t.Fatalf("write file: %s", err)
 		}
 	}

 	// Must run stringer in the temp directory, see TestTags.
 	err := runInDir(t, dir, stringer, "-type=Foo,Bar,Baz", "-output=somefile.go", dir)
 	if err == nil {
 		t.Fatal("unexpected stringer success")
 	}
 }

 var exe struct {
 	path string
 	err  error
 	once sync.Once
 }

 func stringerPath(t *testing.T) string {
 	testenv.NeedsExec(t)

 	exe.once.Do(func() {
 		exe.path, exe.err = os.Executable()
 	})
 	if exe.err != nil {
 		t.Fatal(exe.err)
 	}
 	return exe.path
 }

 // stringerCompileAndRun runs stringer for the named file and compiles and
 // runs the target binary in directory dir. That binary will panic if the String method is incorrect.
 func stringerCompileAndRun(t *testing.T, dir, stringer, typeName, fileName string) {
 	t.Logf("run: %s %s\n", fileName, typeName)
 	source := filepath.Join(dir, path.Base(fileName))
 	err := copy(source, filepath.Join("testdata", fileName))
 	if err != nil {
 		t.Fatalf("copying file to temporary directory: %s", err)
 	}
 	stringSource := filepath.Join(dir, typeName+"_string.go")
 	// Run stringer in temporary directory.
 	err = run(t, stringer, "-type", typeName, "-output", stringSource, source)
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Run the binary in the temporary directory.
 	err = run(t, "go", "run", stringSource, source)
 	if err != nil {
 		t.Fatal(err)
 	}
 }

 // copy copies the from file to the to file.
 func copy(to, from string) error {
 	toFd, err := os.Create(to)
 	if err != nil {
 		return err
 	}
 	defer toFd.Close()
 	fromFd, err := os.Open(from)
 	if err != nil {
 		return err
 	}
 	defer fromFd.Close()
 	_, err = io.Copy(toFd, fromFd)
 	return err
 }

 // run runs a single command and returns an error if it does not succeed.
 // os/exec should have this function, to be honest.
 func run(t testing.TB, name string, arg ...string) error {
 	t.Helper()
 	return runInDir(t, ".", name, arg...)
 }

 // runInDir runs a single command in directory dir and returns an error if
 // it does not succeed.
 func runInDir(t testing.TB, dir, name string, arg ...string) error {
 	t.Helper()
 	cmd := testenv.Command(t, name, arg...)
 	cmd.Dir = dir
 	out, err := cmd.CombinedOutput()
 	if len(out) > 0 {
 		t.Logf("%s", out)
 	}
 	if err != nil {
 		return fmt.Errorf("%v: %v", cmd, err)
 	}
 	return nil
 }
	// Copyright 2014 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.

	// go command is not available on android

	//go:build !android

	package main

	import (
	"bytes"
	"flag"
	"fmt"
	"io"
	"os"
	"path"
	"path/filepath"
	"reflect"
	"slices"
	"strings"
	"sync"
	"testing"

	"golang.org/x/tools/internal/testenv"
	)

	// This file contains a test that compiles and runs each program in testdata
	// after generating the string method for its type. The rule is that for testdata/x.go
	// we run stringer -type X and then compile and run the program. The resulting
	// binary panics if the String method for X is not correct, including for error cases.

	func TestMain(m *testing.M) {
	if os.Getenv("STRINGER_TEST_IS_STRINGER") != "" {
	main()
	os.Exit(0)
	}

	// Inform subprocesses that they should run the cmd/stringer main instead of
	// running tests. It's a close approximation to building and running the real
	// command, and much less complicated and expensive to build and clean up.
	os.Setenv("STRINGER_TEST_IS_STRINGER", "1")

	flag.Parse()
	if testing.Verbose() {
	os.Setenv("GOPACKAGESDEBUG", "true")
	}

	os.Exit(m.Run())
	}

	func TestEndToEnd(t *testing.T) {
	testenv.NeedsTool(t, "go")

	stringer := stringerPath(t)
	// Read the testdata directory.
	fd, err := os.Open("testdata")
	if err != nil {
	t.Fatal(err)
	}
	defer fd.Close()
	names, err := fd.Readdirnames(-1)
	if err != nil {
	t.Fatalf("Readdirnames: %s", err)
	}
	// Generate, compile, and run the test programs.
	for _, name := range names {
	if name == "typeparams" {
	// ignore the directory containing the tests with type params
	continue
	}
	if !strings.HasSuffix(name, ".go") {
	t.Errorf("%s is not a Go file", name)
	continue
	}
	if strings.HasPrefix(name, "tag_") \|\| strings.HasPrefix(name, "vary_") {
	// This file is used for tag processing in TestTags or TestConstValueChange, below.
	continue
	}
	t.Run(name, func(t *testing.T) {
	if name == "cgo.go" {
	testenv.NeedsTool(t, "cgo")
	}
	stringerCompileAndRun(t, t.TempDir(), stringer, typeName(name), name)
	})
	}
	}

	// a type name for stringer. use the last component of the file name with the .go
	func typeName(fname string) string {
	// file names are known to be ascii and end .go
	base := path.Base(fname)
	return fmt.Sprintf("%c%s", base[0]+'A'-'a', base[1:len(base)-len(".go")])
	}

	// TestTags verifies that the -tags flag works as advertised.
	func TestTags(t *testing.T) {
	stringer := stringerPath(t)
	dir := t.TempDir()
	var (
	protectedConst = []byte("TagProtected")
	output = filepath.Join(dir, "const_string.go")
	)
	for _, file := range []string{"tag_main.go", "tag_tag.go"} {
	err := copy(filepath.Join(dir, file), filepath.Join("testdata", file))
	if err != nil {
	t.Fatal(err)
	}
	}
	// Run stringer in the directory that contains the module that contains the package files.
	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module test\n"), 0o600); err != nil {
	t.Fatal(err)
	}
	err := runInDir(t, dir, stringer, "-type", "Const", ".")
	if err != nil {
	t.Fatal(err)
	}
	result, err := os.ReadFile(output)
	if err != nil {
	t.Fatal(err)
	}
	if bytes.Contains(result, protectedConst) {
	t.Fatal("tagged variable appears in untagged run")
	}
	err = os.Remove(output)
	if err != nil {
	t.Fatal(err)
	}
	err = runInDir(t, dir, stringer, "-type", "Const", "-tags", "tag", ".")
	if err != nil {
	t.Fatal(err)
	}
	result, err = os.ReadFile(output)
	if err != nil {
	t.Fatal(err)
	}
	if !bytes.Contains(result, protectedConst) {
	t.Fatal("tagged variable does not appear in tagged run")
	}
	}

	// TestConstValueChange verifies that if a constant value changes and
	// the stringer code is not regenerated, we'll get a compiler error.
	func TestConstValueChange(t *testing.T) {
	testenv.NeedsTool(t, "go")

	stringer := stringerPath(t)
	dir := t.TempDir()
	source := filepath.Join(dir, "day.go")
	err := copy(source, filepath.Join("testdata", "day.go"))
	if err != nil {
	t.Fatal(err)
	}
	stringSource := filepath.Join(dir, "day_string.go")
	// Run stringer in the directory that contains the module that contains the package files.
	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module test\n"), 0o600); err != nil {
	t.Fatal(err)
	}
	err = runInDir(t, dir, stringer, "-type", "Day", "-output", stringSource)
	if err != nil {
	t.Fatal(err)
	}
	// Run the binary in the temporary directory as a sanity check.
	err = run(t, "go", "run", stringSource, source)
	if err != nil {
	t.Fatal(err)
	}
	// Overwrite the source file with a version that has changed constants.
	err = copy(source, filepath.Join("testdata", "vary_day.go"))
	if err != nil {
	t.Fatal(err)
	}
	// Unfortunately different compilers may give different error messages,
	// so there's no easy way to verify that the build failed specifically
	// because the constants changed rather than because the vary_day.go
	// file is invalid.
	//
	// Instead we'll just rely on manual inspection of the polluted test
	// output. An alternative might be to check that the error output
	// matches a set of possible error strings emitted by known
	// Go compilers.
	t.Logf("Note: the following messages should indicate an out-of-bounds compiler error\n")
	err = run(t, "go", "build", stringSource, source)
	if err == nil {
	t.Fatal("unexpected compiler success")
	}
	}

	var testfileSrcs = map[string]string{
	"go.mod": "module foo",

	// Normal file in the package.
	"main.go": `package foo

	type Foo int

	const (
	fooX Foo = iota
	fooY
	fooZ
	)
	`,

	// Test file in the package.
	"main_test.go": `package foo

	type Bar int

	const (
	barX Bar = iota
	barY
	barZ
	)
	`,

	// Test file in the test package.
	"main_pkg_test.go": `package foo_test

	type Baz int

	const (
	bazX Baz = iota
	bazY
	bazZ
	)
	`,
	}

	// Test stringer on types defined in different kinds of tests.
	// The generated code should not interfere between itself.
	func TestTestFiles(t *testing.T) {
	testenv.NeedsTool(t, "go")
	stringer := stringerPath(t)

	dir := t.TempDir()
	t.Logf("TestTestFiles in: %s \n", dir)
	for name, src := range testfileSrcs {
	source := filepath.Join(dir, name)
	err := os.WriteFile(source, []byte(src), 0666)
	if err != nil {
	t.Fatalf("write file: %s", err)
	}
	}

	// Must run stringer in the temp directory, see TestTags.
	err := runInDir(t, dir, stringer, "-type=Foo,Bar,Baz", dir)
	if err != nil {
	t.Fatalf("run stringer: %s", err)
	}

	// Check that stringer has created the expected files.
	content, err := os.ReadDir(dir)
	if err != nil {
	t.Fatalf("read dir: %s", err)
	}
	gotFiles := []string{}
	for _, f := range content {
	if !f.IsDir() {
	gotFiles = append(gotFiles, f.Name())
	}
	}
	wantFiles := []string{
	// Original.
	"go.mod",
	"main.go",
	"main_test.go",
	"main_pkg_test.go",
	// Generated.
	"foo_string.go",
	"bar_string_test.go",
	"baz_string_test.go",
	}
	slices.Sort(gotFiles)
	slices.Sort(wantFiles)
	if !reflect.DeepEqual(gotFiles, wantFiles) {
	t.Errorf("stringer generated files:\n%s\n\nbut want:\n%s",
	strings.Join(gotFiles, "\n"),
	strings.Join(wantFiles, "\n"),
	)
	}

	// Run go test as a smoke test.
	err = runInDir(t, dir, "go", "test", "-count=1", ".")
	if err != nil {
	t.Fatalf("go test: %s", err)
	}
	}

	// The -output flag cannot be used in combiation with matching types across multiple packages.
	func TestCollidingOutput(t *testing.T) {
	testenv.NeedsTool(t, "go")
	stringer := stringerPath(t)

	dir := t.TempDir()
	for name, src := range testfileSrcs {
	source := filepath.Join(dir, name)
	err := os.WriteFile(source, []byte(src), 0666)
	if err != nil {
	t.Fatalf("write file: %s", err)
	}
	}

	// Must run stringer in the temp directory, see TestTags.
	err := runInDir(t, dir, stringer, "-type=Foo,Bar,Baz", "-output=somefile.go", dir)
	if err == nil {
	t.Fatal("unexpected stringer success")
	}
	}

	var exe struct {
	path string
	err error
	once sync.Once
	}

	func stringerPath(t *testing.T) string {
	testenv.NeedsExec(t)

	exe.once.Do(func() {
	exe.path, exe.err = os.Executable()
	})
	if exe.err != nil {
	t.Fatal(exe.err)
	}
	return exe.path
	}

	// stringerCompileAndRun runs stringer for the named file and compiles and
	// runs the target binary in directory dir. That binary will panic if the String method is incorrect.
	func stringerCompileAndRun(t *testing.T, dir, stringer, typeName, fileName string) {
	t.Logf("run: %s %s\n", fileName, typeName)
	source := filepath.Join(dir, path.Base(fileName))
	err := copy(source, filepath.Join("testdata", fileName))
	if err != nil {
	t.Fatalf("copying file to temporary directory: %s", err)
	}
	stringSource := filepath.Join(dir, typeName+"_string.go")
	// Run stringer in temporary directory.
	err = run(t, stringer, "-type", typeName, "-output", stringSource, source)
	if err != nil {
	t.Fatal(err)
	}
	// Run the binary in the temporary directory.
	err = run(t, "go", "run", stringSource, source)
	if err != nil {
	t.Fatal(err)
	}
	}

	// copy copies the from file to the to file.
	func copy(to, from string) error {
	toFd, err := os.Create(to)
	if err != nil {
	return err
	}
	defer toFd.Close()
	fromFd, err := os.Open(from)
	if err != nil {
	return err
	}
	defer fromFd.Close()
	_, err = io.Copy(toFd, fromFd)
	return err
	}

	// run runs a single command and returns an error if it does not succeed.
	// os/exec should have this function, to be honest.
	func run(t testing.TB, name string, arg ...string) error {
	t.Helper()
	return runInDir(t, ".", name, arg...)
	}

	// runInDir runs a single command in directory dir and returns an error if
	// it does not succeed.
	func runInDir(t testing.TB, dir, name string, arg ...string) error {
	t.Helper()
	cmd := testenv.Command(t, name, arg...)
	cmd.Dir = dir
	out, err := cmd.CombinedOutput()
	if len(out) > 0 {
	t.Logf("%s", out)
	}
	if err != nil {
	return fmt.Errorf("%v: %v", cmd, err)
	}
	return nil
	}