whatcanGOwrong

This commit is contained in:
2024-09-19 21:38:24 -04:00
commit d0ae4d841d
17908 changed files with 4096831 additions and 0 deletions
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// Copyright 2023 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.
// Gonew starts a new Go module by copying a template module.
//
// Usage:
//
// gonew srcmod[@version] [dstmod [dir]]
//
// Gonew makes a copy of the srcmod module, changing its module path to dstmod.
// It writes that new module to a new directory named by dir.
// If dir already exists, it must be an empty directory.
// If dir is omitted, gonew uses ./elem where elem is the final path element of dstmod.
//
// This command is highly experimental and subject to change.
//
// # Example
//
// To install gonew:
//
// go install golang.org/x/tools/cmd/gonew@latest
//
// To clone the basic command-line program template golang.org/x/example/hello
// as your.domain/myprog, in the directory ./myprog:
//
// gonew golang.org/x/example/hello your.domain/myprog
//
// To clone the latest copy of the rsc.io/quote module, keeping that module path,
// into ./quote:
//
// gonew rsc.io/quote
package main
import (
"bytes"
"encoding/json"
"flag"
"fmt"
"go/parser"
"go/token"
"io/fs"
"log"
"os"
"os/exec"
"path"
"path/filepath"
"strconv"
"strings"
"golang.org/x/mod/modfile"
"golang.org/x/mod/module"
"golang.org/x/tools/internal/edit"
)
func usage() {
fmt.Fprintf(os.Stderr, "usage: gonew srcmod[@version] [dstmod [dir]]\n")
fmt.Fprintf(os.Stderr, "See https://pkg.go.dev/golang.org/x/tools/cmd/gonew.\n")
os.Exit(2)
}
func main() {
log.SetPrefix("gonew: ")
log.SetFlags(0)
flag.Usage = usage
flag.Parse()
args := flag.Args()
if len(args) < 1 || len(args) > 3 {
usage()
}
srcMod := args[0]
srcModVers := srcMod
if !strings.Contains(srcModVers, "@") {
srcModVers += "@latest"
}
srcMod, _, _ = strings.Cut(srcMod, "@")
if err := module.CheckPath(srcMod); err != nil {
log.Fatalf("invalid source module name: %v", err)
}
dstMod := srcMod
if len(args) >= 2 {
dstMod = args[1]
if err := module.CheckPath(dstMod); err != nil {
log.Fatalf("invalid destination module name: %v", err)
}
}
var dir string
if len(args) == 3 {
dir = args[2]
} else {
dir = "." + string(filepath.Separator) + path.Base(dstMod)
}
// Dir must not exist or must be an empty directory.
de, err := os.ReadDir(dir)
if err == nil && len(de) > 0 {
log.Fatalf("target directory %s exists and is non-empty", dir)
}
needMkdir := err != nil
var stdout, stderr bytes.Buffer
cmd := exec.Command("go", "mod", "download", "-json", srcModVers)
cmd.Stdout = &stdout
cmd.Stderr = &stderr
if err := cmd.Run(); err != nil {
log.Fatalf("go mod download -json %s: %v\n%s%s", srcModVers, err, stderr.Bytes(), stdout.Bytes())
}
var info struct {
Dir string
}
if err := json.Unmarshal(stdout.Bytes(), &info); err != nil {
log.Fatalf("go mod download -json %s: invalid JSON output: %v\n%s%s", srcMod, err, stderr.Bytes(), stdout.Bytes())
}
if needMkdir {
if err := os.MkdirAll(dir, 0777); err != nil {
log.Fatal(err)
}
}
// Copy from module cache into new directory, making edits as needed.
filepath.WalkDir(info.Dir, func(src string, d fs.DirEntry, err error) error {
if err != nil {
log.Fatal(err)
}
rel, err := filepath.Rel(info.Dir, src)
if err != nil {
log.Fatal(err)
}
dst := filepath.Join(dir, rel)
if d.IsDir() {
if err := os.MkdirAll(dst, 0777); err != nil {
log.Fatal(err)
}
return nil
}
data, err := os.ReadFile(src)
if err != nil {
log.Fatal(err)
}
isRoot := !strings.Contains(rel, string(filepath.Separator))
if strings.HasSuffix(rel, ".go") {
data = fixGo(data, rel, srcMod, dstMod, isRoot)
}
if rel == "go.mod" {
data = fixGoMod(data, srcMod, dstMod)
}
if err := os.WriteFile(dst, data, 0666); err != nil {
log.Fatal(err)
}
return nil
})
log.Printf("initialized %s in %s", dstMod, dir)
}
// fixGo rewrites the Go source in data to replace srcMod with dstMod.
// isRoot indicates whether the file is in the root directory of the module,
// in which case we also update the package name.
func fixGo(data []byte, file string, srcMod, dstMod string, isRoot bool) []byte {
fset := token.NewFileSet()
f, err := parser.ParseFile(fset, file, data, parser.ImportsOnly)
if err != nil {
log.Fatalf("parsing source module:\n%s", err)
}
buf := edit.NewBuffer(data)
at := func(p token.Pos) int {
return fset.File(p).Offset(p)
}
srcName := path.Base(srcMod)
dstName := path.Base(dstMod)
if isRoot {
if name := f.Name.Name; name == srcName || name == srcName+"_test" {
dname := dstName + strings.TrimPrefix(name, srcName)
if !token.IsIdentifier(dname) {
log.Fatalf("%s: cannot rename package %s to package %s: invalid package name", file, name, dname)
}
buf.Replace(at(f.Name.Pos()), at(f.Name.End()), dname)
}
}
for _, spec := range f.Imports {
path, err := strconv.Unquote(spec.Path.Value)
if err != nil {
continue
}
if path == srcMod {
if srcName != dstName && spec.Name == nil {
// Add package rename because source code uses original name.
// The renaming looks strange, but template authors are unlikely to
// create a template where the root package is imported by packages
// in subdirectories, and the renaming at least keeps the code working.
// A more sophisticated approach would be to rename the uses of
// the package identifier in the file too, but then you have to worry about
// name collisions, and given how unlikely this is, it doesn't seem worth
// trying to clean up the file that way.
buf.Insert(at(spec.Path.Pos()), srcName+" ")
}
// Change import path to dstMod
buf.Replace(at(spec.Path.Pos()), at(spec.Path.End()), strconv.Quote(dstMod))
}
if strings.HasPrefix(path, srcMod+"/") {
// Change import path to begin with dstMod
buf.Replace(at(spec.Path.Pos()), at(spec.Path.End()), strconv.Quote(strings.Replace(path, srcMod, dstMod, 1)))
}
}
return buf.Bytes()
}
// fixGoMod rewrites the go.mod content in data to replace srcMod with dstMod
// in the module path.
func fixGoMod(data []byte, srcMod, dstMod string) []byte {
f, err := modfile.ParseLax("go.mod", data, nil)
if err != nil {
log.Fatalf("parsing source module:\n%s", err)
}
f.AddModuleStmt(dstMod)
new, err := f.Format()
if err != nil {
return data
}
return new
}
@@ -0,0 +1,218 @@
// Copyright 2023 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/zip"
"bytes"
"fmt"
"io/fs"
"os"
"os/exec"
"path/filepath"
"runtime"
"strings"
"testing"
"golang.org/x/tools/internal/diffp"
"golang.org/x/tools/internal/testenv"
"golang.org/x/tools/txtar"
)
func init() {
if os.Getenv("TestGonewMain") == "1" {
main()
os.Exit(0)
}
}
func Test(t *testing.T) {
if !testenv.HasExec() {
t.Skipf("skipping test: exec not supported on %s/%s", runtime.GOOS, runtime.GOARCH)
}
exe, err := os.Executable()
if err != nil {
t.Fatal(err)
}
// Each file in testdata is a txtar file with the command to run,
// the contents of modules to initialize in a fake proxy,
// the expected stdout and stderr, and the expected file contents.
files, err := filepath.Glob("testdata/*.txt")
if err != nil {
t.Fatal(err)
}
if len(files) == 0 {
t.Fatal("no test cases")
}
for _, file := range files {
t.Run(filepath.Base(file), func(t *testing.T) {
data, err := os.ReadFile(file)
if err != nil {
t.Fatal(err)
}
ar := txtar.Parse(data)
// If the command begins with ! it means it should fail.
// After the optional ! the first argument must be 'gonew'
// followed by the arguments to gonew.
args := strings.Fields(string(ar.Comment))
wantFail := false
if len(args) > 0 && args[0] == "!" {
wantFail = true
args = args[1:]
}
if len(args) == 0 || args[0] != "gonew" {
t.Fatalf("invalid command comment")
}
// Collect modules into proxy tree and store in temp directory.
dir := t.TempDir()
proxyDir := filepath.Join(dir, "proxy")
writeProxyFiles(t, proxyDir, ar)
extra := ""
if runtime.GOOS == "windows" {
// Windows absolute paths don't start with / so we need one more.
extra = "/"
}
proxyURL := "file://" + extra + filepath.ToSlash(proxyDir)
// Run gonew in a fresh 'out' directory.
out := filepath.Join(dir, "out")
if err := os.Mkdir(out, 0777); err != nil {
t.Fatal(err)
}
cmd := exec.Command(exe, args[1:]...)
cmd.Dir = out
cmd.Env = append(os.Environ(), "TestGonewMain=1", "GOPROXY="+proxyURL, "GOSUMDB=off")
var stdout bytes.Buffer
var stderr bytes.Buffer
cmd.Stdout = &stdout
cmd.Stderr = &stderr
if err := cmd.Run(); err == nil && wantFail {
t.Errorf("unexpected success exit")
} else if err != nil && !wantFail {
t.Errorf("unexpected failure exit")
}
// Collect the expected output from the txtar.
want := make(map[string]txtar.File)
for _, f := range ar.Files {
if f.Name == "stdout" || f.Name == "stderr" || strings.HasPrefix(f.Name, "out/") {
want[f.Name] = f
}
}
// Check stdout and stderr.
// Change \ to / so Windows output looks like Unix output.
stdoutBuf := bytes.ReplaceAll(stdout.Bytes(), []byte(`\`), []byte("/"))
stderrBuf := bytes.ReplaceAll(stderr.Bytes(), []byte(`\`), []byte("/"))
// Note that stdout and stderr can be omitted from the archive if empty.
if !bytes.Equal(stdoutBuf, want["stdout"].Data) {
t.Errorf("wrong stdout: %s", diffp.Diff("want", want["stdout"].Data, "have", stdoutBuf))
}
if !bytes.Equal(stderrBuf, want["stderr"].Data) {
t.Errorf("wrong stderr: %s", diffp.Diff("want", want["stderr"].Data, "have", stderrBuf))
}
delete(want, "stdout")
delete(want, "stderr")
// Check remaining expected outputs.
err = filepath.WalkDir(out, func(name string, info fs.DirEntry, err error) error {
if err != nil {
return err
}
if info.IsDir() {
return nil
}
data, err := os.ReadFile(name)
if err != nil {
return err
}
short := "out" + filepath.ToSlash(strings.TrimPrefix(name, out))
f, ok := want[short]
if !ok {
t.Errorf("unexpected file %s:\n%s", short, data)
return nil
}
delete(want, short)
if !bytes.Equal(data, f.Data) {
t.Errorf("wrong %s: %s", short, diffp.Diff("want", f.Data, "have", data))
}
return nil
})
if err != nil {
t.Fatal(err)
}
for name := range want {
t.Errorf("missing file %s", name)
}
})
}
}
// A Zip is a zip file being written.
type Zip struct {
buf bytes.Buffer
w *zip.Writer
}
// writeProxyFiles collects all the module content from ar and writes
// files in the format of the proxy URL space, so that the 'proxy' directory
// can be used in a GOPROXY=file:/// URL.
func writeProxyFiles(t *testing.T, proxy string, ar *txtar.Archive) {
zips := make(map[string]*Zip)
others := make(map[string]string)
for _, f := range ar.Files {
i := strings.Index(f.Name, "@")
if i < 0 {
continue
}
j := strings.Index(f.Name[i:], "/")
if j < 0 {
t.Fatalf("unexpected archive file %s", f.Name)
}
j += i
mod, vers, file := f.Name[:i], f.Name[i+1:j], f.Name[j+1:]
zipName := mod + "/@v/" + vers + ".zip"
z := zips[zipName]
if z == nil {
others[mod+"/@v/list"] += vers + "\n"
others[mod+"/@v/"+vers+".info"] = fmt.Sprintf("{%q: %q}\n", "Version", vers)
z = new(Zip)
z.w = zip.NewWriter(&z.buf)
zips[zipName] = z
}
if file == "go.mod" {
others[mod+"/@v/"+vers+".mod"] = string(f.Data)
}
w, err := z.w.Create(f.Name)
if err != nil {
t.Fatal(err)
}
if _, err := w.Write(f.Data); err != nil {
t.Fatal(err)
}
}
for name, z := range zips {
if err := z.w.Close(); err != nil {
t.Fatal(err)
}
if err := os.MkdirAll(filepath.Dir(filepath.Join(proxy, name)), 0777); err != nil {
t.Fatal(err)
}
if err := os.WriteFile(filepath.Join(proxy, name), z.buf.Bytes(), 0666); err != nil {
t.Fatal(err)
}
}
for name, data := range others {
// zip loop already created directory
if err := os.WriteFile(filepath.Join(proxy, name), []byte(data), 0666); err != nil {
t.Fatal(err)
}
}
}
@@ -0,0 +1,28 @@
gonew example.com/quote my.com/test
-- example.com/quote@v1.5.2/go.mod --
module example.com/quote
-- example.com/quote@v1.5.2/quote.go --
package quote
import (
"example.com/quote/bar"
)
func Quote() {}
-- example.com/quote@v1.5.2/quote/another.go --
package quote // another package quote!
-- stderr --
gonew: initialized my.com/test in ./test
-- out/test/go.mod --
module my.com/test
-- out/test/quote.go --
package test
import (
"my.com/test/bar"
)
func Quote() {}
-- out/test/quote/another.go --
package quote // another package quote!