blob: e7faa4810ab61a3cec293da3dea502fa4d184bee [file] [log] [blame]
// 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
// +build !android
package main
import (
"bytes"
"fmt"
"go/build"
"io"
"os"
"os/exec"
"path"
"path/filepath"
"strings"
"sync"
"testing"
"golang.org/x/tools/internal/testenv"
"golang.org/x/tools/internal/typeparams"
)
// 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")
os.Exit(m.Run())
}
func TestEndToEnd(t *testing.T) {
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)
}
if typeparams.Enabled {
names = append(names, moreTests(t, "testdata/typeparams", "typeparams")...)
}
// 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
}
if name == "cgo.go" && !build.Default.CgoEnabled {
t.Logf("cgo is not enabled for %s", name)
continue
}
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")])
}
func moreTests(t *testing.T, dirname, prefix string) []string {
x, err := os.ReadDir(dirname)
if err != nil {
// error, but try the rest of the tests
t.Errorf("can't read type param tess from %s: %v", dirname, err)
return nil
}
names := make([]string, len(x))
for i, f := range x {
names[i] = prefix + "/" + f.Name()
}
return names
}
// 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 package files.
// We cannot run stringer in the current directory for the following reasons:
// - Versions of Go earlier than Go 1.11, do not support absolute directories as a pattern.
// - When the current directory is inside a go module, the path will not be considered
// a valid path to a package.
err := runInDir(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(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) {
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 package files.
err = runInDir(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("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.
fmt.Fprintf(os.Stderr, "Note: the following messages should indicate an out-of-bounds compiler error\n")
err = run("go", "build", stringSource, source)
if err == nil {
t.Fatal("unexpected compiler 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.Helper()
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(stringer, "-type", typeName, "-output", stringSource, source)
if err != nil {
t.Fatal(err)
}
// Run the binary in the temporary directory.
err = run("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(name string, arg ...string) error {
return runInDir(".", name, arg...)
}
// runInDir runs a single command in directory dir and returns an error if
// it does not succeed.
func runInDir(dir, name string, arg ...string) error {
cmd := exec.Command(name, arg...)
cmd.Dir = dir
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
cmd.Env = append(os.Environ(), "GO111MODULE=auto")
return cmd.Run()
}