src/go/types/check_test.go - go - Git at Google

 // Copyright 2011 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.

 // This file implements a typechecker test harness. The packages specified
 // in tests are typechecked. Error messages reported by the typechecker are
 // compared against the error messages expected in the test files.
 //
 // Expected errors are indicated in the test files by putting a comment
 // of the form /* ERROR "rx" */ immediately following an offending token.
 // The harness will verify that an error matching the regular expression
 // rx is reported at that source position. Consecutive comments may be
 // used to indicate multiple errors for the same token position.
 //
 // For instance, the following test file indicates that a "not declared"
 // error should be reported for the undeclared variable x:
 //
 //	package p
 //	func f() {
 //		_ = x /* ERROR "not declared" */ + 1
 //	}

 package types_test

 import (
 	"bytes"
 	"flag"
 	"fmt"
 	"go/ast"
 	"go/importer"
 	"go/parser"
 	"go/scanner"
 	"go/token"
 	"internal/testenv"
 	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
 	"testing"

 	. "go/types"
 )

 var (
 	haltOnError  = flag.Bool("halt", false, "halt on error")
 	verifyErrors = flag.Bool("verify", false, "verify errors (rather than list them) in TestManual")
 	goVersion    = flag.String("lang", "", "Go language version (e.g. \"go1.12\") for TestManual")
 )

 var fset = token.NewFileSet()

 // Positioned errors are of the form filename:line:column: message .
 var posMsgRx = regexp.MustCompile(`^(.*:[0-9]+:[0-9]+): *(?s)(.*)`)

 // splitError splits an error's error message into a position string
 // and the actual error message. If there's no position information,
 // pos is the empty string, and msg is the entire error message.
 func splitError(err error) (pos, msg string) {
 	msg = err.Error()
 	if m := posMsgRx.FindStringSubmatch(msg); len(m) == 3 {
 		pos = m[1]
 		msg = m[2]
 	}
 	return
 }

 func parseFiles(t *testing.T, filenames []string, srcs [][]byte, mode parser.Mode) ([]*ast.File, []error) {
 	var files []*ast.File
 	var errlist []error
 	for i, filename := range filenames {
 		file, err := parser.ParseFile(fset, filename, srcs[i], mode)
 		if file == nil {
 			t.Fatalf("%s: %s", filename, err)
 		}
 		files = append(files, file)
 		if err != nil {
 			if list, _ := err.(scanner.ErrorList); len(list) > 0 {
 				for _, err := range list {
 					errlist = append(errlist, err)
 				}
 			} else {
 				errlist = append(errlist, err)
 			}
 		}
 	}
 	return files, errlist
 }

 // ERROR comments must start with text `ERROR "rx"` or `ERROR rx` where
 // rx is a regular expression that matches the expected error message.
 // Space around "rx" or rx is ignored. Use the form `ERROR HERE "rx"`
 // for error messages that are located immediately after rather than
 // at a token's position.
 var errRx = regexp.MustCompile(`^ *ERROR *(HERE)? *"?([^"]*)"?`)

 // errMap collects the regular expressions of ERROR comments found
 // in files and returns them as a map of error positions to error messages.
 //
 // srcs must be a slice of the same length as files, containing the original
 // source for the parsed AST.
 func errMap(t *testing.T, files []*ast.File, srcs [][]byte) map[string][]string {
 	// map of position strings to lists of error message patterns
 	errmap := make(map[string][]string)

 	for i, file := range files {
 		tok := fset.File(file.Package)
 		src := srcs[i]
 		var s scanner.Scanner
 		s.Init(tok, src, nil, scanner.ScanComments)
 		var prev token.Pos // position of last non-comment, non-semicolon token
 		var here token.Pos // position immediately after the token at position prev

 	scanFile:
 		for {
 			pos, tok, lit := s.Scan()
 			switch tok {
 			case token.EOF:
 				break scanFile
 			case token.COMMENT:
 				if lit[1] == '*' {
 					lit = lit[:len(lit)-2] // strip trailing */
 				}
 				if s := errRx.FindStringSubmatch(lit[2:]); len(s) == 3 {
 					pos := prev
 					if s[1] == "HERE" {
 						pos = here
 					}
 					p := fset.Position(pos).String()
 					errmap[p] = append(errmap[p], strings.TrimSpace(s[2]))
 				}
 			case token.SEMICOLON:
 				// ignore automatically inserted semicolon
 				if lit == "\n" {
 					continue scanFile
 				}
 				fallthrough
 			default:
 				prev = pos
 				var l int // token length
 				if tok.IsLiteral() {
 					l = len(lit)
 				} else {
 					l = len(tok.String())
 				}
 				here = prev + token.Pos(l)
 			}
 		}
 	}

 	return errmap
 }

 func eliminate(t *testing.T, errmap map[string][]string, errlist []error) {
 	for _, err := range errlist {
 		pos, gotMsg := splitError(err)
 		list := errmap[pos]
 		index := -1 // list index of matching message, if any
 		// we expect one of the messages in list to match the error at pos
 		for i, wantRx := range list {
 			rx, err := regexp.Compile(wantRx)
 			if err != nil {
 				t.Errorf("%s: %v", pos, err)
 				continue
 			}
 			if rx.MatchString(gotMsg) {
 				index = i
 				break
 			}
 		}
 		if index >= 0 {
 			// eliminate from list
 			if n := len(list) - 1; n > 0 {
 				// not the last entry - swap in last element and shorten list by 1
 				list[index] = list[n]
 				errmap[pos] = list[:n]
 			} else {
 				// last entry - remove list from map
 				delete(errmap, pos)
 			}
 		} else {
 			t.Errorf("%s: no error expected: %q", pos, gotMsg)
 		}
 	}
 }

 // parseFlags parses flags from the first line of the given source
 // (from src if present, or by reading from the file) if the line
 // starts with "//" (line comment) followed by "-" (possiby with
 // spaces between). Otherwise the line is ignored.
 func parseFlags(filename string, src []byte, flags *flag.FlagSet) error {
 	// If there is no src, read from the file.
 	const maxLen = 256
 	if len(src) == 0 {
 		f, err := os.Open(filename)
 		if err != nil {
 			return err
 		}

 		var buf [maxLen]byte
 		n, err := f.Read(buf[:])
 		if err != nil {
 			return err
 		}
 		src = buf[:n]
 	}

 	// we must have a line comment that starts with a "-"
 	const prefix = "//"
 	if !bytes.HasPrefix(src, []byte(prefix)) {
 		return nil // first line is not a line comment
 	}
 	src = src[len(prefix):]
 	if i := bytes.Index(src, []byte("-")); i < 0 || len(bytes.TrimSpace(src[:i])) != 0 {
 		return nil // comment doesn't start with a "-"
 	}
 	end := bytes.Index(src, []byte("\n"))
 	if end < 0 || end > maxLen {
 		return fmt.Errorf("flags comment line too long")
 	}

 	return flags.Parse(strings.Fields(string(src[:end])))
 }

 func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, manual bool, imp Importer) {
 	if len(filenames) == 0 {
 		t.Fatal("no source files")
 	}

 	var conf Config
 	conf.Sizes = sizes
 	flags := flag.NewFlagSet("", flag.PanicOnError)
 	flags.StringVar(&conf.GoVersion, "lang", "", "")
 	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
 	if err := parseFlags(filenames[0], srcs[0], flags); err != nil {
 		t.Fatal(err)
 	}

 	if manual && *goVersion != "" {
 		// goVersion overrides -lang for manual tests.
 		conf.GoVersion = *goVersion
 	}

 	// TODO(gri) remove this or use flag mechanism to set mode if still needed
 	if strings.HasSuffix(filenames[0], ".go1") {
 		// TODO(rfindley): re-enable this test by using GoVersion.
 		t.Skip("type params are enabled")
 	}

 	files, errlist := parseFiles(t, filenames, srcs, parser.AllErrors)

 	pkgName := "<no package>"
 	if len(files) > 0 {
 		pkgName = files[0].Name.Name
 	}

 	listErrors := manual && !*verifyErrors
 	if listErrors && len(errlist) > 0 {
 		t.Errorf("--- %s:", pkgName)
 		for _, err := range errlist {
 			t.Error(err)
 		}
 	}

 	// typecheck and collect typechecker errors
 	if imp == nil {
 		imp = importer.Default()
 	}
 	conf.Importer = imp
 	conf.Error = func(err error) {
 		if *haltOnError {
 			defer panic(err)
 		}
 		if listErrors {
 			t.Error(err)
 			return
 		}
 		// Ignore secondary error messages starting with "\t";
 		// they are clarifying messages for a primary error.
 		if !strings.Contains(err.Error(), ": \t") {
 			errlist = append(errlist, err)
 		}
 	}
 	conf.Check(pkgName, fset, files, nil)

 	if listErrors {
 		return
 	}

 	for _, err := range errlist {
 		err, ok := err.(Error)
 		if !ok {
 			continue
 		}
 		code := readCode(err)
 		if code == 0 {
 			t.Errorf("missing error code: %v", err)
 		}
 	}

 	// match and eliminate errors;
 	// we are expecting the following errors
 	errmap := errMap(t, files, srcs)
 	eliminate(t, errmap, errlist)

 	// there should be no expected errors left
 	if len(errmap) > 0 {
 		t.Errorf("--- %s: %d source positions with expected (but not reported) errors:", pkgName, len(errmap))
 		for pos, list := range errmap {
 			for _, rx := range list {
 				t.Errorf("%s: %q", pos, rx)
 			}
 		}
 	}
 }

 // TestManual is for manual testing of a package - either provided
 // as a list of filenames belonging to the package, or a directory
 // name containing the package files - after the test arguments
 // (and a separating "--"). For instance, to test the package made
 // of the files foo.go and bar.go, use:
 //
 //	go test -run Manual -- foo.go bar.go
 //
 // If no source arguments are provided, the file testdata/manual.go
 // is used instead.
 // Provide the -verify flag to verify errors against ERROR comments
 // in the input files rather than having a list of errors reported.
 // The accepted Go language version can be controlled with the -lang
 // flag.
 func TestManual(t *testing.T) {
 	testenv.MustHaveGoBuild(t)

 	filenames := flag.Args()
 	if len(filenames) == 0 {
 		filenames = []string{filepath.FromSlash("testdata/manual.go")}
 	}

 	info, err := os.Stat(filenames[0])
 	if err != nil {
 		t.Fatalf("TestManual: %v", err)
 	}

 	DefPredeclaredTestFuncs()
 	if info.IsDir() {
 		if len(filenames) > 1 {
 			t.Fatal("TestManual: must have only one directory argument")
 		}
 		testDir(t, filenames[0], true)
 	} else {
 		testPkg(t, filenames, true)
 	}
 }

 func TestLongConstants(t *testing.T) {
 	format := "package longconst\n\nconst _ = %s\nconst _ = %s // ERROR excessively long constant"
 	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
 	testFiles(t, nil, []string{"longconst.go"}, [][]byte{[]byte(src)}, false, nil)
 }

 // TestIndexRepresentability tests that constant index operands must
 // be representable as int even if they already have a type that can
 // represent larger values.
 func TestIndexRepresentability(t *testing.T) {
 	const src = "package index\n\nvar s []byte\nvar _ = s[int64 /* ERROR \"int64\\(1\\) << 40 \\(.*\\) overflows int\" */ (1) << 40]"
 	testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false, nil)
 }

 func TestIssue47243_TypedRHS(t *testing.T) {
 	// The RHS of the shift expression below overflows uint on 32bit platforms,
 	// but this is OK as it is explicitly typed.
 	const src = "package issue47243\n\nvar a uint64; var _ = a << uint64(4294967296)" // uint64(1<<32)
 	testFiles(t, &StdSizes{4, 4}, []string{"p.go"}, [][]byte{[]byte(src)}, false, nil)
 }

 func TestCheck(t *testing.T)     { testDirFiles(t, "testdata/check", false) }
 func TestSpec(t *testing.T)      { testDirFiles(t, "testdata/spec", false) }
 func TestExamples(t *testing.T)  { testDirFiles(t, "testdata/examples", false) }
 func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", false) }

 func testDirFiles(t *testing.T, dir string, manual bool) {
 	testenv.MustHaveGoBuild(t)
 	dir = filepath.FromSlash(dir)

 	fis, err := os.ReadDir(dir)
 	if err != nil {
 		t.Error(err)
 		return
 	}

 	for _, fi := range fis {
 		path := filepath.Join(dir, fi.Name())

 		// If fi is a directory, its files make up a single package.
 		if fi.IsDir() {
 			testDir(t, path, manual)
 		} else {
 			t.Run(filepath.Base(path), func(t *testing.T) {
 				testPkg(t, []string{path}, manual)
 			})
 		}
 	}
 }

 func testDir(t *testing.T, dir string, manual bool) {
 	testenv.MustHaveGoBuild(t)

 	fis, err := os.ReadDir(dir)
 	if err != nil {
 		t.Error(err)
 		return
 	}

 	var filenames []string
 	for _, fi := range fis {
 		filenames = append(filenames, filepath.Join(dir, fi.Name()))
 	}

 	t.Run(filepath.Base(dir), func(t *testing.T) {
 		testPkg(t, filenames, manual)
 	})
 }

 // TODO(rFindley) reconcile the different test setup in go/types with types2.
 func testPkg(t *testing.T, filenames []string, manual bool) {
 	srcs := make([][]byte, len(filenames))
 	for i, filename := range filenames {
 		src, err := os.ReadFile(filename)
 		if err != nil {
 			t.Fatalf("could not read %s: %v", filename, err)
 		}
 		srcs[i] = src
 	}
 	testFiles(t, nil, filenames, srcs, manual, nil)
 }
	// Copyright 2011 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.

	// This file implements a typechecker test harness. The packages specified
	// in tests are typechecked. Error messages reported by the typechecker are
	// compared against the error messages expected in the test files.
	//
	// Expected errors are indicated in the test files by putting a comment
	// of the form /* ERROR "rx" */ immediately following an offending token.
	// The harness will verify that an error matching the regular expression
	// rx is reported at that source position. Consecutive comments may be
	// used to indicate multiple errors for the same token position.
	//
	// For instance, the following test file indicates that a "not declared"
	// error should be reported for the undeclared variable x:
	//
	// package p
	// func f() {
	// _ = x /* ERROR "not declared" */ + 1
	// }

	package types_test

	import (
	"bytes"
	"flag"
	"fmt"
	"go/ast"
	"go/importer"
	"go/parser"
	"go/scanner"
	"go/token"
	"internal/testenv"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"testing"

	. "go/types"
	)

	var (
	haltOnError = flag.Bool("halt", false, "halt on error")
	verifyErrors = flag.Bool("verify", false, "verify errors (rather than list them) in TestManual")
	goVersion = flag.String("lang", "", "Go language version (e.g. \"go1.12\") for TestManual")
	)

	var fset = token.NewFileSet()

	// Positioned errors are of the form filename:line:column: message .
	var posMsgRx = regexp.MustCompile(`^(.:[0-9]+:[0-9]+): (?s)(.*)`)

	// splitError splits an error's error message into a position string
	// and the actual error message. If there's no position information,
	// pos is the empty string, and msg is the entire error message.
	func splitError(err error) (pos, msg string) {
	msg = err.Error()
	if m := posMsgRx.FindStringSubmatch(msg); len(m) == 3 {
	pos = m[1]
	msg = m[2]
	}
	return
	}

	func parseFiles(t testing.T, filenames []string, srcs [][]byte, mode parser.Mode) ([]ast.File, []error) {
	var files []*ast.File
	var errlist []error
	for i, filename := range filenames {
	file, err := parser.ParseFile(fset, filename, srcs[i], mode)
	if file == nil {
	t.Fatalf("%s: %s", filename, err)
	}
	files = append(files, file)
	if err != nil {
	if list, _ := err.(scanner.ErrorList); len(list) > 0 {
	for _, err := range list {
	errlist = append(errlist, err)
	}
	} else {
	errlist = append(errlist, err)
	}
	}
	}
	return files, errlist
	}

	// ERROR comments must start with text `ERROR "rx"` or `ERROR rx` where
	// rx is a regular expression that matches the expected error message.
	// Space around "rx" or rx is ignored. Use the form `ERROR HERE "rx"`
	// for error messages that are located immediately after rather than
	// at a token's position.
	var errRx = regexp.MustCompile(`^ ERROR (HERE)? "?([^"])"?`)

	// errMap collects the regular expressions of ERROR comments found
	// in files and returns them as a map of error positions to error messages.
	//
	// srcs must be a slice of the same length as files, containing the original
	// source for the parsed AST.
	func errMap(t testing.T, files []ast.File, srcs [][]byte) map[string][]string {
	// map of position strings to lists of error message patterns
	errmap := make(map[string][]string)

	for i, file := range files {
	tok := fset.File(file.Package)
	src := srcs[i]
	var s scanner.Scanner
	s.Init(tok, src, nil, scanner.ScanComments)
	var prev token.Pos // position of last non-comment, non-semicolon token
	var here token.Pos // position immediately after the token at position prev

	scanFile:
	for {
	pos, tok, lit := s.Scan()
	switch tok {
	case token.EOF:
	break scanFile
	case token.COMMENT:
	if lit[1] == '*' {
	lit = lit[:len(lit)-2] // strip trailing */
	}
	if s := errRx.FindStringSubmatch(lit[2:]); len(s) == 3 {
	pos := prev
	if s[1] == "HERE" {
	pos = here
	}
	p := fset.Position(pos).String()
	errmap[p] = append(errmap[p], strings.TrimSpace(s[2]))
	}
	case token.SEMICOLON:
	// ignore automatically inserted semicolon
	if lit == "\n" {
	continue scanFile
	}
	fallthrough
	default:
	prev = pos
	var l int // token length
	if tok.IsLiteral() {
	l = len(lit)
	} else {
	l = len(tok.String())
	}
	here = prev + token.Pos(l)
	}
	}
	}

	return errmap
	}

	func eliminate(t *testing.T, errmap map[string][]string, errlist []error) {
	for _, err := range errlist {
	pos, gotMsg := splitError(err)
	list := errmap[pos]
	index := -1 // list index of matching message, if any
	// we expect one of the messages in list to match the error at pos
	for i, wantRx := range list {
	rx, err := regexp.Compile(wantRx)
	if err != nil {
	t.Errorf("%s: %v", pos, err)
	continue
	}
	if rx.MatchString(gotMsg) {
	index = i
	break
	}
	}
	if index >= 0 {
	// eliminate from list
	if n := len(list) - 1; n > 0 {
	// not the last entry - swap in last element and shorten list by 1
	list[index] = list[n]
	errmap[pos] = list[:n]
	} else {
	// last entry - remove list from map
	delete(errmap, pos)
	}
	} else {
	t.Errorf("%s: no error expected: %q", pos, gotMsg)
	}
	}
	}

	// parseFlags parses flags from the first line of the given source
	// (from src if present, or by reading from the file) if the line
	// starts with "//" (line comment) followed by "-" (possiby with
	// spaces between). Otherwise the line is ignored.
	func parseFlags(filename string, src []byte, flags *flag.FlagSet) error {
	// If there is no src, read from the file.
	const maxLen = 256
	if len(src) == 0 {
	f, err := os.Open(filename)
	if err != nil {
	return err
	}

	var buf [maxLen]byte
	n, err := f.Read(buf[:])
	if err != nil {
	return err
	}
	src = buf[:n]
	}

	// we must have a line comment that starts with a "-"
	const prefix = "//"
	if !bytes.HasPrefix(src, []byte(prefix)) {
	return nil // first line is not a line comment
	}
	src = src[len(prefix):]
	if i := bytes.Index(src, []byte("-")); i < 0 \|\| len(bytes.TrimSpace(src[:i])) != 0 {
	return nil // comment doesn't start with a "-"
	}
	end := bytes.Index(src, []byte("\n"))
	if end < 0 \|\| end > maxLen {
	return fmt.Errorf("flags comment line too long")
	}

	return flags.Parse(strings.Fields(string(src[:end])))
	}

	func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, manual bool, imp Importer) {
	if len(filenames) == 0 {
	t.Fatal("no source files")
	}

	var conf Config
	conf.Sizes = sizes
	flags := flag.NewFlagSet("", flag.PanicOnError)
	flags.StringVar(&conf.GoVersion, "lang", "", "")
	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
	if err := parseFlags(filenames[0], srcs[0], flags); err != nil {
	t.Fatal(err)
	}

	if manual && *goVersion != "" {
	// goVersion overrides -lang for manual tests.
	conf.GoVersion = *goVersion
	}

	// TODO(gri) remove this or use flag mechanism to set mode if still needed
	if strings.HasSuffix(filenames[0], ".go1") {
	// TODO(rfindley): re-enable this test by using GoVersion.
	t.Skip("type params are enabled")
	}

	files, errlist := parseFiles(t, filenames, srcs, parser.AllErrors)

	pkgName := "<no package>"
	if len(files) > 0 {
	pkgName = files[0].Name.Name
	}

	listErrors := manual && !*verifyErrors
	if listErrors && len(errlist) > 0 {
	t.Errorf("--- %s:", pkgName)
	for _, err := range errlist {
	t.Error(err)
	}
	}

	// typecheck and collect typechecker errors
	if imp == nil {
	imp = importer.Default()
	}
	conf.Importer = imp
	conf.Error = func(err error) {
	if *haltOnError {
	defer panic(err)
	}
	if listErrors {
	t.Error(err)
	return
	}
	// Ignore secondary error messages starting with "\t";
	// they are clarifying messages for a primary error.
	if !strings.Contains(err.Error(), ": \t") {
	errlist = append(errlist, err)
	}
	}
	conf.Check(pkgName, fset, files, nil)

	if listErrors {
	return
	}

	for _, err := range errlist {
	err, ok := err.(Error)
	if !ok {
	continue
	}
	code := readCode(err)
	if code == 0 {
	t.Errorf("missing error code: %v", err)
	}
	}

	// match and eliminate errors;
	// we are expecting the following errors
	errmap := errMap(t, files, srcs)
	eliminate(t, errmap, errlist)

	// there should be no expected errors left
	if len(errmap) > 0 {
	t.Errorf("--- %s: %d source positions with expected (but not reported) errors:", pkgName, len(errmap))
	for pos, list := range errmap {
	for _, rx := range list {
	t.Errorf("%s: %q", pos, rx)
	}
	}
	}
	}

	// TestManual is for manual testing of a package - either provided
	// as a list of filenames belonging to the package, or a directory
	// name containing the package files - after the test arguments
	// (and a separating "--"). For instance, to test the package made
	// of the files foo.go and bar.go, use:
	//
	// go test -run Manual -- foo.go bar.go
	//
	// If no source arguments are provided, the file testdata/manual.go
	// is used instead.
	// Provide the -verify flag to verify errors against ERROR comments
	// in the input files rather than having a list of errors reported.
	// The accepted Go language version can be controlled with the -lang
	// flag.
	func TestManual(t *testing.T) {
	testenv.MustHaveGoBuild(t)

	filenames := flag.Args()
	if len(filenames) == 0 {
	filenames = []string{filepath.FromSlash("testdata/manual.go")}
	}

	info, err := os.Stat(filenames[0])
	if err != nil {
	t.Fatalf("TestManual: %v", err)
	}

	DefPredeclaredTestFuncs()
	if info.IsDir() {
	if len(filenames) > 1 {
	t.Fatal("TestManual: must have only one directory argument")
	}
	testDir(t, filenames[0], true)
	} else {
	testPkg(t, filenames, true)
	}
	}

	func TestLongConstants(t *testing.T) {
	format := "package longconst\n\nconst _ = %s\nconst _ = %s // ERROR excessively long constant"
	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
	testFiles(t, nil, []string{"longconst.go"}, [][]byte{[]byte(src)}, false, nil)
	}

	// TestIndexRepresentability tests that constant index operands must
	// be representable as int even if they already have a type that can
	// represent larger values.
	func TestIndexRepresentability(t *testing.T) {
	const src = "package index\n\nvar s []byte\nvar _ = s[int64 /* ERROR \"int64\\(1\\) << 40 \\(.\\) overflows int\" / (1) << 40]"
	testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false, nil)
	}

	func TestIssue47243_TypedRHS(t *testing.T) {
	// The RHS of the shift expression below overflows uint on 32bit platforms,
	// but this is OK as it is explicitly typed.
	const src = "package issue47243\n\nvar a uint64; var _ = a << uint64(4294967296)" // uint64(1<<32)
	testFiles(t, &StdSizes{4, 4}, []string{"p.go"}, [][]byte{[]byte(src)}, false, nil)
	}

	func TestCheck(t *testing.T) { testDirFiles(t, "testdata/check", false) }
	func TestSpec(t *testing.T) { testDirFiles(t, "testdata/spec", false) }
	func TestExamples(t *testing.T) { testDirFiles(t, "testdata/examples", false) }
	func TestFixedbugs(t *testing.T) { testDirFiles(t, "testdata/fixedbugs", false) }

	func testDirFiles(t *testing.T, dir string, manual bool) {
	testenv.MustHaveGoBuild(t)
	dir = filepath.FromSlash(dir)

	fis, err := os.ReadDir(dir)
	if err != nil {
	t.Error(err)
	return
	}

	for _, fi := range fis {
	path := filepath.Join(dir, fi.Name())

	// If fi is a directory, its files make up a single package.
	if fi.IsDir() {
	testDir(t, path, manual)
	} else {
	t.Run(filepath.Base(path), func(t *testing.T) {
	testPkg(t, []string{path}, manual)
	})
	}
	}
	}

	func testDir(t *testing.T, dir string, manual bool) {
	testenv.MustHaveGoBuild(t)

	fis, err := os.ReadDir(dir)
	if err != nil {
	t.Error(err)
	return
	}

	var filenames []string
	for _, fi := range fis {
	filenames = append(filenames, filepath.Join(dir, fi.Name()))
	}

	t.Run(filepath.Base(dir), func(t *testing.T) {
	testPkg(t, filenames, manual)
	})
	}

	// TODO(rFindley) reconcile the different test setup in go/types with types2.
	func testPkg(t *testing.T, filenames []string, manual bool) {
	srcs := make([][]byte, len(filenames))
	for i, filename := range filenames {
	src, err := os.ReadFile(filename)
	if err != nil {
	t.Fatalf("could not read %s: %v", filename, err)
	}
	srcs[i] = src
	}
	testFiles(t, nil, filenames, srcs, manual, nil)
	}