source: imaps-frontend/node_modules/eslint/lib/rules/prefer-regex-literals.js@ d565449

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Last change on this file since d565449 was d565449, checked in by stefan toskovski <stefantoska84@…>, 4 weeks ago

Update repo after prototype presentation
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1/**
2 * @fileoverview Rule to disallow use of the `RegExp` constructor in favor of regular expression literals
3 * @author Milos Djermanovic
4 */
5
6"use strict";
7
8//------------------------------------------------------------------------------
9// Requirements
10//------------------------------------------------------------------------------
11
12const astUtils = require("./utils/ast-utils");
13const { CALL, CONSTRUCT, ReferenceTracker, findVariable } = require("@eslint-community/eslint-utils");
14const { RegExpValidator, visitRegExpAST, RegExpParser } = require("@eslint-community/regexpp");
15const { canTokensBeAdjacent } = require("./utils/ast-utils");
16const { REGEXPP_LATEST_ECMA_VERSION } = require("./utils/regular-expressions");
17
18//------------------------------------------------------------------------------
19// Helpers
20//------------------------------------------------------------------------------
21
22/**
23 * Determines whether the given node is a string literal.
24 * @param {ASTNode} node Node to check.
25 * @returns {boolean} True if the node is a string literal.
26 */
27function isStringLiteral(node) {
28 return node.type === "Literal" && typeof node.value === "string";
29}
30
31/**
32 * Determines whether the given node is a regex literal.
33 * @param {ASTNode} node Node to check.
34 * @returns {boolean} True if the node is a regex literal.
35 */
36function isRegexLiteral(node) {
37 return node.type === "Literal" && Object.prototype.hasOwnProperty.call(node, "regex");
38}
39
40const validPrecedingTokens = new Set([
41 "(",
42 ";",
43 "[",
44 ",",
45 "=",
46 "+",
47 "*",
48 "-",
49 "?",
50 "~",
51 "%",
52 "**",
53 "!",
54 "typeof",
55 "instanceof",
56 "&&",
57 "||",
58 "??",
59 "return",
60 "...",
61 "delete",
62 "void",
63 "in",
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 "do",
98 "break",
99 "continue",
100 "debugger",
101 "case",
102 "throw"
103]);
104
105
106//------------------------------------------------------------------------------
107// Rule Definition
108//------------------------------------------------------------------------------
109
110/** @type {import('../shared/types').Rule} */
111module.exports = {
112 meta: {
113 type: "suggestion",
114
115 docs: {
116 description: "Disallow use of the `RegExp` constructor in favor of regular expression literals",
117 recommended: false,
118 url: "https://eslint.org/docs/latest/rules/prefer-regex-literals"
119 },
120
121 hasSuggestions: true,
122
123 schema: [
124 {
125 type: "object",
126 properties: {
127 disallowRedundantWrapping: {
128 type: "boolean",
129 default: false
130 }
131 },
132 additionalProperties: false
133 }
134 ],
135
136 messages: {
137 unexpectedRegExp: "Use a regular expression literal instead of the 'RegExp' constructor.",
138 replaceWithLiteral: "Replace with an equivalent regular expression literal.",
139 replaceWithLiteralAndFlags: "Replace with an equivalent regular expression literal with flags '{{ flags }}'.",
140 replaceWithIntendedLiteralAndFlags: "Replace with a regular expression literal with flags '{{ flags }}'.",
141 unexpectedRedundantRegExp: "Regular expression literal is unnecessarily wrapped within a 'RegExp' constructor.",
142 unexpectedRedundantRegExpWithFlags: "Use regular expression literal with flags instead of the 'RegExp' constructor."
143 }
144 },
145
146 create(context) {
147 const [{ disallowRedundantWrapping = false } = {}] = context.options;
148 const sourceCode = context.sourceCode;
149
150 /**
151 * Determines whether the given identifier node is a reference to a global variable.
152 * @param {ASTNode} node `Identifier` node to check.
153 * @returns {boolean} True if the identifier is a reference to a global variable.
154 */
155 function isGlobalReference(node) {
156 const scope = sourceCode.getScope(node);
157 const variable = findVariable(scope, node);
158
159 return variable !== null && variable.scope.type === "global" && variable.defs.length === 0;
160 }
161
162 /**
163 * Determines whether the given node is a String.raw`` tagged template expression
164 * with a static template literal.
165 * @param {ASTNode} node Node to check.
166 * @returns {boolean} True if the node is String.raw`` with a static template.
167 */
168 function isStringRawTaggedStaticTemplateLiteral(node) {
169 return node.type === "TaggedTemplateExpression" &&
170 astUtils.isSpecificMemberAccess(node.tag, "String", "raw") &&
171 isGlobalReference(astUtils.skipChainExpression(node.tag).object) &&
172 astUtils.isStaticTemplateLiteral(node.quasi);
173 }
174
175 /**
176 * Gets the value of a string
177 * @param {ASTNode} node The node to get the string of.
178 * @returns {string|null} The value of the node.
179 */
180 function getStringValue(node) {
181 if (isStringLiteral(node)) {
182 return node.value;
183 }
184
185 if (astUtils.isStaticTemplateLiteral(node)) {
186 return node.quasis[0].value.cooked;
187 }
188
189 if (isStringRawTaggedStaticTemplateLiteral(node)) {
190 return node.quasi.quasis[0].value.raw;
191 }
192
193 return null;
194 }
195
196 /**
197 * Determines whether the given node is considered to be a static string by the logic of this rule.
198 * @param {ASTNode} node Node to check.
199 * @returns {boolean} True if the node is a static string.
200 */
201 function isStaticString(node) {
202 return isStringLiteral(node) ||
203 astUtils.isStaticTemplateLiteral(node) ||
204 isStringRawTaggedStaticTemplateLiteral(node);
205 }
206
207 /**
208 * Determines whether the relevant arguments of the given are all static string literals.
209 * @param {ASTNode} node Node to check.
210 * @returns {boolean} True if all arguments are static strings.
211 */
212 function hasOnlyStaticStringArguments(node) {
213 const args = node.arguments;
214
215 if ((args.length === 1 || args.length === 2) && args.every(isStaticString)) {
216 return true;
217 }
218
219 return false;
220 }
221
222 /**
223 * Determines whether the arguments of the given node indicate that a regex literal is unnecessarily wrapped.
224 * @param {ASTNode} node Node to check.
225 * @returns {boolean} True if the node already contains a regex literal argument.
226 */
227 function isUnnecessarilyWrappedRegexLiteral(node) {
228 const args = node.arguments;
229
230 if (args.length === 1 && isRegexLiteral(args[0])) {
231 return true;
232 }
233
234 if (args.length === 2 && isRegexLiteral(args[0]) && isStaticString(args[1])) {
235 return true;
236 }
237
238 return false;
239 }
240
241 /**
242 * Returns a ecmaVersion compatible for regexpp.
243 * @param {number} ecmaVersion The ecmaVersion to convert.
244 * @returns {import("@eslint-community/regexpp/ecma-versions").EcmaVersion} The resulting ecmaVersion compatible for regexpp.
245 */
246 function getRegexppEcmaVersion(ecmaVersion) {
247 if (ecmaVersion <= 5) {
248 return 5;
249 }
250 return Math.min(ecmaVersion, REGEXPP_LATEST_ECMA_VERSION);
251 }
252
253 const regexppEcmaVersion = getRegexppEcmaVersion(context.languageOptions.ecmaVersion);
254
255 /**
256 * Makes a character escaped or else returns null.
257 * @param {string} character The character to escape.
258 * @returns {string} The resulting escaped character.
259 */
260 function resolveEscapes(character) {
261 switch (character) {
262 case "\n":
263 case "\\\n":
264 return "\\n";
265
266 case "\r":
267 case "\\\r":
268 return "\\r";
269
270 case "\t":
271 case "\\\t":
272 return "\\t";
273
274 case "\v":
275 case "\\\v":
276 return "\\v";
277
278 case "\f":
279 case "\\\f":
280 return "\\f";
281
282 case "/":
283 return "\\/";
284
285 default:
286 return null;
287 }
288 }
289
290 /**
291 * Checks whether the given regex and flags are valid for the ecma version or not.
292 * @param {string} pattern The regex pattern to check.
293 * @param {string | undefined} flags The regex flags to check.
294 * @returns {boolean} True if the given regex pattern and flags are valid for the ecma version.
295 */
296 function isValidRegexForEcmaVersion(pattern, flags) {
297 const validator = new RegExpValidator({ ecmaVersion: regexppEcmaVersion });
298
299 try {
300 validator.validatePattern(pattern, 0, pattern.length, {
301 unicode: flags ? flags.includes("u") : false,
302 unicodeSets: flags ? flags.includes("v") : false
303 });
304 if (flags) {
305 validator.validateFlags(flags);
306 }
307 return true;
308 } catch {
309 return false;
310 }
311 }
312
313 /**
314 * Checks whether two given regex flags contain the same flags or not.
315 * @param {string} flagsA The regex flags.
316 * @param {string} flagsB The regex flags.
317 * @returns {boolean} True if two regex flags contain same flags.
318 */
319 function areFlagsEqual(flagsA, flagsB) {
320 return [...flagsA].sort().join("") === [...flagsB].sort().join("");
321 }
322
323
324 /**
325 * Merges two regex flags.
326 * @param {string} flagsA The regex flags.
327 * @param {string} flagsB The regex flags.
328 * @returns {string} The merged regex flags.
329 */
330 function mergeRegexFlags(flagsA, flagsB) {
331 const flagsSet = new Set([
332 ...flagsA,
333 ...flagsB
334 ]);
335
336 return [...flagsSet].join("");
337 }
338
339 /**
340 * Checks whether a give node can be fixed to the given regex pattern and flags.
341 * @param {ASTNode} node The node to check.
342 * @param {string} pattern The regex pattern to check.
343 * @param {string} flags The regex flags
344 * @returns {boolean} True if a node can be fixed to the given regex pattern and flags.
345 */
346 function canFixTo(node, pattern, flags) {
347 const tokenBefore = sourceCode.getTokenBefore(node);
348
349 return sourceCode.getCommentsInside(node).length === 0 &&
350 (!tokenBefore || validPrecedingTokens.has(tokenBefore.value)) &&
351 isValidRegexForEcmaVersion(pattern, flags);
352 }
353
354 /**
355 * Returns a safe output code considering the before and after tokens.
356 * @param {ASTNode} node The regex node.
357 * @param {string} newRegExpValue The new regex expression value.
358 * @returns {string} The output code.
359 */
360 function getSafeOutput(node, newRegExpValue) {
361 const tokenBefore = sourceCode.getTokenBefore(node);
362 const tokenAfter = sourceCode.getTokenAfter(node);
363
364 return (tokenBefore && !canTokensBeAdjacent(tokenBefore, newRegExpValue) && tokenBefore.range[1] === node.range[0] ? " " : "") +
365 newRegExpValue +
366 (tokenAfter && !canTokensBeAdjacent(newRegExpValue, tokenAfter) && node.range[1] === tokenAfter.range[0] ? " " : "");
367
368 }
369
370 return {
371 Program(node) {
372 const scope = sourceCode.getScope(node);
373 const tracker = new ReferenceTracker(scope);
374 const traceMap = {
375 RegExp: {
376 [CALL]: true,
377 [CONSTRUCT]: true
378 }
379 };
380
381 for (const { node: refNode } of tracker.iterateGlobalReferences(traceMap)) {
382 if (disallowRedundantWrapping && isUnnecessarilyWrappedRegexLiteral(refNode)) {
383 const regexNode = refNode.arguments[0];
384
385 if (refNode.arguments.length === 2) {
386 const suggests = [];
387
388 const argFlags = getStringValue(refNode.arguments[1]) || "";
389
390 if (canFixTo(refNode, regexNode.regex.pattern, argFlags)) {
391 suggests.push({
392 messageId: "replaceWithLiteralAndFlags",
393 pattern: regexNode.regex.pattern,
394 flags: argFlags
395 });
396 }
397
398 const literalFlags = regexNode.regex.flags || "";
399 const mergedFlags = mergeRegexFlags(literalFlags, argFlags);
400
401 if (
402 !areFlagsEqual(mergedFlags, argFlags) &&
403 canFixTo(refNode, regexNode.regex.pattern, mergedFlags)
404 ) {
405 suggests.push({
406 messageId: "replaceWithIntendedLiteralAndFlags",
407 pattern: regexNode.regex.pattern,
408 flags: mergedFlags
409 });
410 }
411
412 context.report({
413 node: refNode,
414 messageId: "unexpectedRedundantRegExpWithFlags",
415 suggest: suggests.map(({ flags, pattern, messageId }) => ({
416 messageId,
417 data: {
418 flags
419 },
420 fix(fixer) {
421 return fixer.replaceText(refNode, getSafeOutput(refNode, `/${pattern}/${flags}`));
422 }
423 }))
424 });
425 } else {
426 const outputs = [];
427
428 if (canFixTo(refNode, regexNode.regex.pattern, regexNode.regex.flags)) {
429 outputs.push(sourceCode.getText(regexNode));
430 }
431
432
433 context.report({
434 node: refNode,
435 messageId: "unexpectedRedundantRegExp",
436 suggest: outputs.map(output => ({
437 messageId: "replaceWithLiteral",
438 fix(fixer) {
439 return fixer.replaceText(
440 refNode,
441 getSafeOutput(refNode, output)
442 );
443 }
444 }))
445 });
446 }
447 } else if (hasOnlyStaticStringArguments(refNode)) {
448 let regexContent = getStringValue(refNode.arguments[0]);
449 let noFix = false;
450 let flags;
451
452 if (refNode.arguments[1]) {
453 flags = getStringValue(refNode.arguments[1]);
454 }
455
456 if (!canFixTo(refNode, regexContent, flags)) {
457 noFix = true;
458 }
459
460 if (!/^[-a-zA-Z0-9\\[\](){} \t\r\n\v\f!@#$%^&*+^_=/~`.><?,'"|:;]*$/u.test(regexContent)) {
461 noFix = true;
462 }
463
464 if (regexContent && !noFix) {
465 let charIncrease = 0;
466
467 const ast = new RegExpParser({ ecmaVersion: regexppEcmaVersion }).parsePattern(regexContent, 0, regexContent.length, {
468 unicode: flags ? flags.includes("u") : false,
469 unicodeSets: flags ? flags.includes("v") : false
470 });
471
472 visitRegExpAST(ast, {
473 onCharacterEnter(characterNode) {
474 const escaped = resolveEscapes(characterNode.raw);
475
476 if (escaped) {
477 regexContent =
478 regexContent.slice(0, characterNode.start + charIncrease) +
479 escaped +
480 regexContent.slice(characterNode.end + charIncrease);
481
482 if (characterNode.raw.length === 1) {
483 charIncrease += 1;
484 }
485 }
486 }
487 });
488 }
489
490 const newRegExpValue = `/${regexContent || "(?:)"}/${flags || ""}`;
491
492 context.report({
493 node: refNode,
494 messageId: "unexpectedRegExp",
495 suggest: noFix ? [] : [{
496 messageId: "replaceWithLiteral",
497 fix(fixer) {
498 return fixer.replaceText(refNode, getSafeOutput(refNode, newRegExpValue));
499 }
500 }]
501 });
502 }
503 }
504 }
505 };
506 }
507};
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