1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358
|
// Copyright 2018 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 expect
import (
"fmt"
"go/ast"
"go/parser"
"go/token"
"path/filepath"
"regexp"
"strconv"
"strings"
"text/scanner"
"golang.org/x/mod/modfile"
)
const commentStart = "@"
const commentStartLen = len(commentStart)
// Identifier is the type for an identifier in an Note argument list.
type Identifier string
// Parse collects all the notes present in a file.
// If content is nil, the filename specified is read and parsed, otherwise the
// content is used and the filename is used for positions and error messages.
// Each comment whose text starts with @ is parsed as a comma-separated
// sequence of notes.
// See the package documentation for details about the syntax of those
// notes.
func Parse(fset *token.FileSet, filename string, content []byte) ([]*Note, error) {
var src interface{}
if content != nil {
src = content
}
switch filepath.Ext(filename) {
case ".go":
// TODO: We should write this in terms of the scanner.
// there are ways you can break the parser such that it will not add all the
// comments to the ast, which may result in files where the tests are silently
// not run.
file, err := parser.ParseFile(fset, filename, src, parser.ParseComments|parser.AllErrors)
if file == nil {
return nil, err
}
return ExtractGo(fset, file)
case ".mod":
file, err := modfile.Parse(filename, content, nil)
if err != nil {
return nil, err
}
f := fset.AddFile(filename, -1, len(content))
f.SetLinesForContent(content)
notes, err := extractModWork(fset, file.Syntax.Stmt)
if err != nil {
return nil, err
}
// Since modfile.Parse does not return an *ast, we need to add the offset
// within the file's contents to the file's base relative to the fileset.
for _, note := range notes {
note.Pos += token.Pos(f.Base())
}
return notes, nil
case ".work":
file, err := modfile.ParseWork(filename, content, nil)
if err != nil {
return nil, err
}
f := fset.AddFile(filename, -1, len(content))
f.SetLinesForContent(content)
notes, err := extractModWork(fset, file.Syntax.Stmt)
if err != nil {
return nil, err
}
// As with go.mod files, we need to compute a synthetic token.Pos.
for _, note := range notes {
note.Pos += token.Pos(f.Base())
}
return notes, nil
}
return nil, nil
}
// extractModWork collects all the notes present in a go.mod file or go.work
// file, by way of the shared modfile.Expr statement node.
//
// Each comment whose text starts with @ is parsed as a comma-separated
// sequence of notes.
// See the package documentation for details about the syntax of those
// notes.
// Only allow notes to appear with the following format: "//@mark()" or // @mark()
func extractModWork(fset *token.FileSet, exprs []modfile.Expr) ([]*Note, error) {
var notes []*Note
for _, stmt := range exprs {
comment := stmt.Comment()
if comment == nil {
continue
}
var allComments []modfile.Comment
allComments = append(allComments, comment.Before...)
allComments = append(allComments, comment.Suffix...)
for _, cmt := range allComments {
text, adjust := getAdjustedNote(cmt.Token)
if text == "" {
continue
}
parsed, err := parse(fset, token.Pos(int(cmt.Start.Byte)+adjust), text)
if err != nil {
return nil, err
}
notes = append(notes, parsed...)
}
}
return notes, nil
}
// ExtractGo collects all the notes present in an AST.
// Each comment whose text starts with @ is parsed as a comma-separated
// sequence of notes.
// See the package documentation for details about the syntax of those
// notes.
func ExtractGo(fset *token.FileSet, file *ast.File) ([]*Note, error) {
var notes []*Note
for _, g := range file.Comments {
for _, c := range g.List {
text, adjust := getAdjustedNote(c.Text)
if text == "" {
continue
}
parsed, err := parse(fset, token.Pos(int(c.Pos())+adjust), text)
if err != nil {
return nil, err
}
notes = append(notes, parsed...)
}
}
return notes, nil
}
func getAdjustedNote(text string) (string, int) {
if strings.HasPrefix(text, "/*") {
text = strings.TrimSuffix(text, "*/")
}
text = text[2:] // remove "//" or "/*" prefix
// Allow notes to appear within comments.
// For example:
// "// //@mark()" is valid.
// "// @mark()" is not valid.
// "// /*@mark()*/" is not valid.
var adjust int
if i := strings.Index(text, commentStart); i > 2 {
// Get the text before the commentStart.
pre := text[i-2 : i]
if pre != "//" {
return "", 0
}
text = text[i:]
adjust = i
}
if !strings.HasPrefix(text, commentStart) {
return "", 0
}
text = text[commentStartLen:]
return text, commentStartLen + adjust + 1
}
const invalidToken rune = 0
type tokens struct {
scanner scanner.Scanner
current rune
err error
base token.Pos
}
func (t *tokens) Init(base token.Pos, text string) *tokens {
t.base = base
t.scanner.Init(strings.NewReader(text))
t.scanner.Mode = scanner.GoTokens
t.scanner.Whitespace ^= 1 << '\n' // don't skip new lines
t.scanner.Error = func(s *scanner.Scanner, msg string) {
t.Errorf("%v", msg)
}
return t
}
func (t *tokens) Consume() string {
t.current = invalidToken
return t.scanner.TokenText()
}
func (t *tokens) Token() rune {
if t.err != nil {
return scanner.EOF
}
if t.current == invalidToken {
t.current = t.scanner.Scan()
}
return t.current
}
func (t *tokens) Skip(r rune) int {
i := 0
for t.Token() == '\n' {
t.Consume()
i++
}
return i
}
func (t *tokens) TokenString() string {
return scanner.TokenString(t.Token())
}
func (t *tokens) Pos() token.Pos {
return t.base + token.Pos(t.scanner.Position.Offset)
}
func (t *tokens) Errorf(msg string, args ...interface{}) {
if t.err != nil {
return
}
t.err = fmt.Errorf(msg, args...)
}
func parse(fset *token.FileSet, base token.Pos, text string) ([]*Note, error) {
t := new(tokens).Init(base, text)
notes := parseComment(t)
if t.err != nil {
return nil, fmt.Errorf("%v:%s", fset.Position(t.Pos()), t.err)
}
return notes, nil
}
func parseComment(t *tokens) []*Note {
var notes []*Note
for {
t.Skip('\n')
switch t.Token() {
case scanner.EOF:
return notes
case scanner.Ident:
notes = append(notes, parseNote(t))
default:
t.Errorf("unexpected %s parsing comment, expect identifier", t.TokenString())
return nil
}
switch t.Token() {
case scanner.EOF:
return notes
case ',', '\n':
t.Consume()
default:
t.Errorf("unexpected %s parsing comment, expect separator", t.TokenString())
return nil
}
}
}
func parseNote(t *tokens) *Note {
n := &Note{
Pos: t.Pos(),
Name: t.Consume(),
}
switch t.Token() {
case ',', '\n', scanner.EOF:
// no argument list present
return n
case '(':
n.Args = parseArgumentList(t)
return n
default:
t.Errorf("unexpected %s parsing note", t.TokenString())
return nil
}
}
func parseArgumentList(t *tokens) []interface{} {
args := []interface{}{} // @name() is represented by a non-nil empty slice.
t.Consume() // '('
t.Skip('\n')
for t.Token() != ')' {
args = append(args, parseArgument(t))
if t.Token() != ',' {
break
}
t.Consume()
t.Skip('\n')
}
if t.Token() != ')' {
t.Errorf("unexpected %s parsing argument list", t.TokenString())
return nil
}
t.Consume() // ')'
return args
}
func parseArgument(t *tokens) interface{} {
switch t.Token() {
case scanner.Ident:
v := t.Consume()
switch v {
case "true":
return true
case "false":
return false
case "nil":
return nil
case "re":
if t.Token() != scanner.String && t.Token() != scanner.RawString {
t.Errorf("re must be followed by string, got %s", t.TokenString())
return nil
}
pattern, _ := strconv.Unquote(t.Consume()) // can't fail
re, err := regexp.Compile(pattern)
if err != nil {
t.Errorf("invalid regular expression %s: %v", pattern, err)
return nil
}
return re
default:
return Identifier(v)
}
case scanner.String, scanner.RawString:
v, _ := strconv.Unquote(t.Consume()) // can't fail
return v
case scanner.Int:
s := t.Consume()
v, err := strconv.ParseInt(s, 0, 0)
if err != nil {
t.Errorf("cannot convert %v to int: %v", s, err)
}
return v
case scanner.Float:
s := t.Consume()
v, err := strconv.ParseFloat(s, 64)
if err != nil {
t.Errorf("cannot convert %v to float: %v", s, err)
}
return v
case scanner.Char:
t.Errorf("unexpected char literal %s", t.Consume())
return nil
default:
t.Errorf("unexpected %s parsing argument", t.TokenString())
return nil
}
}
|