internal/cuetxtar/txtar.go - cue - Git at Google

 // Copyright 2020 CUE Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package cuetxtar

 import (
 	"bufio"
 	"bytes"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
 	"testing"

 	"cuelang.org/go/cue/ast"
 	"cuelang.org/go/cue/build"
 	"cuelang.org/go/cue/errors"
 	"cuelang.org/go/cue/format"
 	"cuelang.org/go/cue/load"
 	"cuelang.org/go/internal/cuetest"
 	"github.com/google/go-cmp/cmp"
 	"github.com/rogpeppe/go-internal/txtar"
 )

 // A TxTarTest represents a test run that process all CUE tests in the txtar
 // format rooted in a given directory.
 type TxTarTest struct {
 	// Run TxTarTest on this directory.
 	Root string

 	// Name is a unique name for this test. The golden file for this test is
 	// derived from the out/<name> file in the .txtar file.
 	//
 	// TODO: by default derive from the current base directory name.
 	Name string

 	// If Update is true, TestTxTar will update the out/Name file if it differs
 	// from the original input. The user must set the output in Gold for this
 	// to be detected.
 	Update bool

 	// Skip is a map of tests to skip to their skip message.
 	Skip map[string]string

 	// ToDo is a map of tests that should be skipped now, but should be fixed.
 	ToDo map[string]string
 }

 // A Test represents a single test based on a .txtar file.
 //
 // A Test embeds *testing.T and should be used to report errors.
 //
 // A Test also embeds a *bytes.Buffer which is used to report test results,
 // which are compared against the golden file for the test in the TxTar archive.
 // If the test fails and the update flag is set to true, the Archive will be
 // updated and written to disk.
 type Test struct {
 	// Allow Test to be used as a T.
 	*testing.T

 	prefix   string
 	buf      *bytes.Buffer // the default buffer
 	outFiles []file

 	Archive *txtar.Archive

 	// The absolute path of the current test directory.
 	Dir string

 	hasGold bool
 }

 func (t *Test) Write(b []byte) (n int, err error) {
 	if t.buf == nil {
 		t.buf = &bytes.Buffer{}
 		t.outFiles = append(t.outFiles, file{t.prefix, t.buf})
 	}
 	return t.buf.Write(b)
 }

 type file struct {
 	name string
 	buf  *bytes.Buffer
 }

 func (t *Test) HasTag(key string) bool {
 	prefix := []byte("#" + key)
 	s := bufio.NewScanner(bytes.NewReader(t.Archive.Comment))
 	for s.Scan() {
 		b := s.Bytes()
 		if bytes.Equal(bytes.TrimSpace(b), prefix) {
 			return true
 		}
 	}
 	return false
 }

 func (t *Test) Value(key string) (value string, ok bool) {
 	prefix := []byte("#" + key + ":")
 	s := bufio.NewScanner(bytes.NewReader(t.Archive.Comment))
 	for s.Scan() {
 		b := s.Bytes()
 		if bytes.HasPrefix(b, prefix) {
 			return string(bytes.TrimSpace(b[len(prefix):])), true
 		}
 	}
 	return "", false
 }

 // Bool searches for a line starting with #key: value in the comment and
 // returns true if the key exists and the value is true.
 func (t *Test) Bool(key string) bool {
 	s, ok := t.Value(key)
 	return ok && s == "true"
 }

 // Rel converts filename to a normalized form so that it will given the same
 // output across different runs and OSes.
 func (t *Test) Rel(filename string) string {
 	rel, err := filepath.Rel(t.Dir, filename)
 	if err != nil {
 		return filepath.Base(filename)
 	}
 	return filepath.ToSlash(rel)
 }

 // WriteErrors writes strings and
 func (t *Test) WriteErrors(err errors.Error) {
 	if err != nil {
 		errors.Print(t, err, &errors.Config{
 			Cwd:     t.Dir,
 			ToSlash: true,
 		})
 	}
 }

 // Write file in a directory.
 func (t *Test) WriteFile(f *ast.File) {
 	// TODO: use FileWriter instead in separate CL.
 	fmt.Fprintln(t, "==", filepath.Base(f.Filename))
 	_, _ = t.Write(formatNode(t.T, f))
 }

 // Writer returns a Writer with the given name.
 func (t *Test) Writer(name string) io.Writer {
 	switch name {
 	case "":
 		name = t.prefix
 	default:
 		name = path.Join(t.prefix, name)
 	}

 	for _, f := range t.outFiles {
 		if f.name == name {
 			return f.buf
 		}
 	}

 	w := &bytes.Buffer{}
 	t.outFiles = append(t.outFiles, file{name, w})

 	if name == t.prefix {
 		t.buf = w
 	}

 	return w
 }

 func formatNode(t *testing.T, n ast.Node) []byte {
 	t.Helper()

 	b, err := format.Node(n)
 	if err != nil {
 		t.Fatal(err)
 	}
 	return b
 }

 // ValidInstances returns the valid instances for this .txtar file or skips the
 // test if there is an error loading the instances.
 func (t *Test) ValidInstances(args ...string) []*build.Instance {
 	a := t.RawInstances(args...)
 	for _, i := range a {
 		if i.Err != nil {
 			if t.hasGold {
 				t.Fatal("Parse error: ", i.Err)
 			}
 			t.Skip("Parse error: ", i.Err)
 		}
 	}
 	return a
 }

 // RawInstances returns the intstances represented by this .txtar file. The
 // returned instances are not checked for errors.
 func (t *Test) RawInstances(args ...string) []*build.Instance {
 	return Load(t.Archive, t.Dir, args...)
 }

 // Load loads the intstances of a txtar file. By default, it only loads
 // files in the root directory. Relative files in the archive are given an
 // absolution location by prefixing it with dir.
 func Load(a *txtar.Archive, dir string, args ...string) []*build.Instance {
 	auto := len(args) == 0
 	overlay := map[string]load.Source{}
 	for _, f := range a.Files {
 		if auto && !strings.Contains(f.Name, "/") {
 			args = append(args, f.Name)
 		}
 		overlay[filepath.Join(dir, f.Name)] = load.FromBytes(f.Data)
 	}

 	cfg := &load.Config{
 		Dir:     dir,
 		Overlay: overlay,
 	}

 	return load.Instances(args, cfg)
 }

 // Run runs tests defined in txtar files in root or its subdirectories.
 // Only tests for which an `old/name` test output file exists are run.
 func (x *TxTarTest) Run(t *testing.T, f func(tc *Test)) {
 	dir, err := os.Getwd()
 	if err != nil {
 		t.Fatal(err)
 	}

 	root := x.Root

 	err = filepath.Walk(root, func(fullpath string, info os.FileInfo, err error) error {
 		if err != nil {
 			t.Fatal(err)
 		}

 		if info.IsDir() || filepath.Ext(fullpath) != ".txtar" {
 			return nil
 		}

 		str := filepath.ToSlash(fullpath)
 		p := strings.Index(str, "/testdata/")
 		testName := str[p+len("/testdata/") : len(str)-len(".txtar")]

 		t.Run(testName, func(t *testing.T) {
 			a, err := txtar.ParseFile(fullpath)
 			if err != nil {
 				t.Fatalf("error parsing txtar file: %v", err)
 			}

 			tc := &Test{
 				T:       t,
 				Archive: a,
 				Dir:     filepath.Dir(filepath.Join(dir, fullpath)),

 				prefix: path.Join("out", x.Name),
 			}

 			for _, f := range a.Files {
 				// TODO: not entirely correct.
 				if strings.HasPrefix(f.Name, tc.prefix) {
 					tc.hasGold = true
 				}
 			}

 			if tc.HasTag("skip") {
 				t.Skip()
 			}

 			if msg, ok := x.Skip[testName]; ok {
 				t.Skip(msg)
 			}
 			if msg, ok := x.ToDo[testName]; ok {
 				t.Skip(msg)
 			}

 			f(tc)

 			update := false
 			for _, sub := range tc.outFiles {
 				var gold *txtar.File
 				for i, f := range a.Files {
 					if f.Name == sub.name {
 						gold = &a.Files[i]
 					}
 				}

 				result := sub.buf.Bytes()

 				switch {
 				case gold == nil:
 					a.Files = append(a.Files, txtar.File{Name: sub.name})
 					gold = &a.Files[len(a.Files)-1]

 				case bytes.Equal(gold.Data, result):
 					continue
 				}

 				if x.Update || cuetest.UpdateGoldenFiles {
 					update = true
 					gold.Data = result
 					continue
 				}

 				t.Errorf("result for %s differs:\n%s",
 					sub.name,
 					cmp.Diff(string(gold.Data), string(result)))
 			}

 			if update {
 				err = ioutil.WriteFile(fullpath, txtar.Format(a), 0644)
 				if err != nil {
 					t.Fatal(err)
 				}
 			}
 		})

 		return nil
 	})

 	if err != nil {
 		t.Fatal(err)
 	}
 }
	// Copyright 2020 CUE Authors
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package cuetxtar

	import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path"
	"path/filepath"
	"strings"
	"testing"

	"cuelang.org/go/cue/ast"
	"cuelang.org/go/cue/build"
	"cuelang.org/go/cue/errors"
	"cuelang.org/go/cue/format"
	"cuelang.org/go/cue/load"
	"cuelang.org/go/internal/cuetest"
	"github.com/google/go-cmp/cmp"
	"github.com/rogpeppe/go-internal/txtar"
	)

	// A TxTarTest represents a test run that process all CUE tests in the txtar
	// format rooted in a given directory.
	type TxTarTest struct {
	// Run TxTarTest on this directory.
	Root string

	// Name is a unique name for this test. The golden file for this test is
	// derived from the out/<name> file in the .txtar file.
	//
	// TODO: by default derive from the current base directory name.
	Name string

	// If Update is true, TestTxTar will update the out/Name file if it differs
	// from the original input. The user must set the output in Gold for this
	// to be detected.
	Update bool

	// Skip is a map of tests to skip to their skip message.
	Skip map[string]string

	// ToDo is a map of tests that should be skipped now, but should be fixed.
	ToDo map[string]string
	}

	// A Test represents a single test based on a .txtar file.
	//
	// A Test embeds *testing.T and should be used to report errors.
	//
	// A Test also embeds a *bytes.Buffer which is used to report test results,
	// which are compared against the golden file for the test in the TxTar archive.
	// If the test fails and the update flag is set to true, the Archive will be
	// updated and written to disk.
	type Test struct {
	// Allow Test to be used as a T.
	*testing.T

	prefix string
	buf *bytes.Buffer // the default buffer
	outFiles []file

	Archive *txtar.Archive

	// The absolute path of the current test directory.
	Dir string

	hasGold bool
	}

	func (t *Test) Write(b []byte) (n int, err error) {
	if t.buf == nil {
	t.buf = &bytes.Buffer{}
	t.outFiles = append(t.outFiles, file{t.prefix, t.buf})
	}
	return t.buf.Write(b)
	}

	type file struct {
	name string
	buf *bytes.Buffer
	}

	func (t *Test) HasTag(key string) bool {
	prefix := []byte("#" + key)
	s := bufio.NewScanner(bytes.NewReader(t.Archive.Comment))
	for s.Scan() {
	b := s.Bytes()
	if bytes.Equal(bytes.TrimSpace(b), prefix) {
	return true
	}
	}
	return false
	}

	func (t *Test) Value(key string) (value string, ok bool) {
	prefix := []byte("#" + key + ":")
	s := bufio.NewScanner(bytes.NewReader(t.Archive.Comment))
	for s.Scan() {
	b := s.Bytes()
	if bytes.HasPrefix(b, prefix) {
	return string(bytes.TrimSpace(b[len(prefix):])), true
	}
	}
	return "", false
	}

	// Bool searches for a line starting with #key: value in the comment and
	// returns true if the key exists and the value is true.
	func (t *Test) Bool(key string) bool {
	s, ok := t.Value(key)
	return ok && s == "true"
	}

	// Rel converts filename to a normalized form so that it will given the same
	// output across different runs and OSes.
	func (t *Test) Rel(filename string) string {
	rel, err := filepath.Rel(t.Dir, filename)
	if err != nil {
	return filepath.Base(filename)
	}
	return filepath.ToSlash(rel)
	}

	// WriteErrors writes strings and
	func (t *Test) WriteErrors(err errors.Error) {
	if err != nil {
	errors.Print(t, err, &errors.Config{
	Cwd: t.Dir,
	ToSlash: true,
	})
	}
	}

	// Write file in a directory.
	func (t Test) WriteFile(f ast.File) {
	// TODO: use FileWriter instead in separate CL.
	fmt.Fprintln(t, "==", filepath.Base(f.Filename))
	_, _ = t.Write(formatNode(t.T, f))
	}

	// Writer returns a Writer with the given name.
	func (t *Test) Writer(name string) io.Writer {
	switch name {
	case "":
	name = t.prefix
	default:
	name = path.Join(t.prefix, name)
	}

	for _, f := range t.outFiles {
	if f.name == name {
	return f.buf
	}
	}

	w := &bytes.Buffer{}
	t.outFiles = append(t.outFiles, file{name, w})

	if name == t.prefix {
	t.buf = w
	}

	return w
	}

	func formatNode(t *testing.T, n ast.Node) []byte {
	t.Helper()

	b, err := format.Node(n)
	if err != nil {
	t.Fatal(err)
	}
	return b
	}

	// ValidInstances returns the valid instances for this .txtar file or skips the
	// test if there is an error loading the instances.
	func (t Test) ValidInstances(args ...string) []build.Instance {
	a := t.RawInstances(args...)
	for _, i := range a {
	if i.Err != nil {
	if t.hasGold {
	t.Fatal("Parse error: ", i.Err)
	}
	t.Skip("Parse error: ", i.Err)
	}
	}
	return a
	}

	// RawInstances returns the intstances represented by this .txtar file. The
	// returned instances are not checked for errors.
	func (t Test) RawInstances(args ...string) []build.Instance {
	return Load(t.Archive, t.Dir, args...)
	}

	// Load loads the intstances of a txtar file. By default, it only loads
	// files in the root directory. Relative files in the archive are given an
	// absolution location by prefixing it with dir.
	func Load(a txtar.Archive, dir string, args ...string) []build.Instance {
	auto := len(args) == 0
	overlay := map[string]load.Source{}
	for _, f := range a.Files {
	if auto && !strings.Contains(f.Name, "/") {
	args = append(args, f.Name)
	}
	overlay[filepath.Join(dir, f.Name)] = load.FromBytes(f.Data)
	}

	cfg := &load.Config{
	Dir: dir,
	Overlay: overlay,
	}

	return load.Instances(args, cfg)
	}

	// Run runs tests defined in txtar files in root or its subdirectories.
	// Only tests for which an `old/name` test output file exists are run.
	func (x TxTarTest) Run(t testing.T, f func(tc *Test)) {
	dir, err := os.Getwd()
	if err != nil {
	t.Fatal(err)
	}

	root := x.Root

	err = filepath.Walk(root, func(fullpath string, info os.FileInfo, err error) error {
	if err != nil {
	t.Fatal(err)
	}

	if info.IsDir() \|\| filepath.Ext(fullpath) != ".txtar" {
	return nil
	}

	str := filepath.ToSlash(fullpath)
	p := strings.Index(str, "/testdata/")
	testName := str[p+len("/testdata/") : len(str)-len(".txtar")]

	t.Run(testName, func(t *testing.T) {
	a, err := txtar.ParseFile(fullpath)
	if err != nil {
	t.Fatalf("error parsing txtar file: %v", err)
	}

	tc := &Test{
	T: t,
	Archive: a,
	Dir: filepath.Dir(filepath.Join(dir, fullpath)),

	prefix: path.Join("out", x.Name),
	}

	for _, f := range a.Files {
	// TODO: not entirely correct.
	if strings.HasPrefix(f.Name, tc.prefix) {
	tc.hasGold = true
	}
	}

	if tc.HasTag("skip") {
	t.Skip()
	}

	if msg, ok := x.Skip[testName]; ok {
	t.Skip(msg)
	}
	if msg, ok := x.ToDo[testName]; ok {
	t.Skip(msg)
	}

	f(tc)

	update := false
	for _, sub := range tc.outFiles {
	var gold *txtar.File
	for i, f := range a.Files {
	if f.Name == sub.name {
	gold = &a.Files[i]
	}
	}

	result := sub.buf.Bytes()

	switch {
	case gold == nil:
	a.Files = append(a.Files, txtar.File{Name: sub.name})
	gold = &a.Files[len(a.Files)-1]

	case bytes.Equal(gold.Data, result):
	continue
	}

	if x.Update \|\| cuetest.UpdateGoldenFiles {
	update = true
	gold.Data = result
	continue
	}

	t.Errorf("result for %s differs:\n%s",
	sub.name,
	cmp.Diff(string(gold.Data), string(result)))
	}

	if update {
	err = ioutil.WriteFile(fullpath, txtar.Format(a), 0644)
	if err != nil {
	t.Fatal(err)
	}
	}
	})

	return nil
	})

	if err != nil {
	t.Fatal(err)
	}
	}