feat: Suggestions support for prefer-regex-literals

lib/rules/prefer-regex-literals.js

@@ -11,6 +11,8 @@
 
 const astUtils = require("./utils/ast-utils");
 const { CALL, CONSTRUCT, ReferenceTracker, findVariable } = require("eslint-utils");
+const { RegExpValidator, visitRegExpAST, RegExpParser } = require("regexpp");
+const { canTokensBeAdjacent } = require("./utils/ast-utils");
 
 //------------------------------------------------------------------------------
 // Helpers
@@ -43,6 +45,71 @@ function isStaticTemplateLiteral(node) {
     return node.type === "TemplateLiteral" && node.expressions.length === 0;
 }
 
+const validPrecedingTokens = [
+    "(",
+    ";",
+    "[",
+    ",",
+    "=",
+    "+",
+    "*",
+    "-",
+    "?",
+    "~",
+    "%",
+    "**",
+    "!",
+    "typeof",
+    "instanceof",
+    "&&",
+    "||",
+    "??",
+    "return",
+    "...",
+    "delete",
+    "void",
+    "in",
+    "<",
+    ">",
+    "<=",
+    ">=",
+    "==",
+    "===",
+    "!=",
+    "!==",
+    "<<",
+    ">>",
+    ">>>",
+    "&",
+    "|",
+    "^",
+    ":",
+    "{",
+    "=>",
+    "*=",
+    "<<=",
+    ">>=",
+    ">>>=",
+    "^=",
+    "|=",
+    "&=",
+    "??=",
+    "||=",
+    "&&=",
+    "**=",
+    "+=",
+    "-=",
+    "/=",
+    "%=",
+    "/",
+    "do",
+    "break",
+    "continue",
+    "debugger",
+    "case",
+    "throw"
+];
+
 
 //------------------------------------------------------------------------------
 // Rule Definition
@@ -58,6 +125,8 @@ module.exports = {
             url: "https://eslint.org/docs/rules/prefer-regex-literals"
         },
 
+        hasSuggestions: true,
+
         schema: [
             {
                 type: "object",
@@ -80,6 +149,8 @@ module.exports = {
 
     create(context) {
         const [{ disallowRedundantWrapping = false } = {}] = context.options;
+        const sourceCode = context.getSourceCode();
+        const text = sourceCode.getText();
 
         /**
          * Determines whether the given identifier node is a reference to a global variable.
@@ -106,6 +177,27 @@ module.exports = {
                 isStaticTemplateLiteral(node.quasi);
         }
 
+        /**
+         * Gets the value of a string
+         * @param {ASTNode} node The node to get the string of.
+         * @returns {string|null} The value of the node.
+         */
+        function getStringValue(node) {
+            if (isStringLiteral(node)) {
+                return node.value;
+            }
+
+            if (isStaticTemplateLiteral(node)) {
+                return node.quasis[0].value.cooked;
+            }
+
+            if (isStringRawTaggedStaticTemplateLiteral(node)) {
+                return node.quasi.quasis[0].value.raw;
+            }
+
+            return null;
+        }
+
         /**
          * Determines whether the given node is considered to be a static string by the logic of this rule.
          * @param {ASTNode} node Node to check.
@@ -151,6 +243,55 @@ module.exports = {
             return false;
         }
 
+        /* eslint-disable jsdoc/valid-types -- eslint-plugin-jsdoc's type parser doesn't support square brackets */
+        /**
+         * Returns a ecmaVersion compatible for regexpp.
+         * @param {import("../linter/linter").ParserOptions["ecmaVersion"]} ecmaVersion The ecmaVersion to convert.
+         * @returns {import("regexpp/ecma-versions").EcmaVersion} The resulting ecmaVersion compatible for regexpp.
+         */
+        function getRegexppEcmaVersion(ecmaVersion) {
+            /* eslint-enable jsdoc/valid-types -- JSDoc is over, enable jsdoc/valid-types again */
+            if (!ecmaVersion || ecmaVersion > 13 || ecmaVersion === 3 || ecmaVersion === 5) {
+                return 5;
+            }
+            return ecmaVersion + 2009;
+        }
+
+        /**
+         * Makes a character escaped or else returns null.
+         * @param {string} character The character to escape.
+         * @returns {string} The resulting escaped character.
+         */
+        function resolveEscapes(character) {
+            switch (character) {
+                case "\n":
+                case "\\\n":
+                    return "\\n";
+
+                case "\r":
+                case "\\\r":
+                    return "\\r";
+
+                case "\t":
+                case "\\\t":
+                    return "\\t";
+
+                case "\v":
+                case "\\\v":
+                    return "\\v";
+
+                case "\f":
+                case "\\\f":
+                    return "\\f";
+
+                case "/":
+                    return "\\/";
+
+                default:
+                    return null;
+            }
+        }
+
         return {
             Program() {
                 const scope = context.getScope();
@@ -170,7 +311,80 @@ module.exports = {
                             context.report({ node, messageId: "unexpectedRedundantRegExp" });
                         }
                     } else if (hasOnlyStaticStringArguments(node)) {
-                        context.report({ node, messageId: "unexpectedRegExp" });
+                        let regexContent = getStringValue(node.arguments[0]);
+                        let noFix = false;
+                        let flags;
+
+                        if (node.arguments[1]) {
+                            flags = getStringValue(node.arguments[1]);
+                        }
+
+                        const regexppEcmaVersion = getRegexppEcmaVersion(context.parserOptions.ecmaVersion);
+                        const RegExpValidatorInstance = new RegExpValidator({ ecmaVersion: regexppEcmaVersion });
+
+                        try {
+                            RegExpValidatorInstance.validatePattern(regexContent, 0, regexContent.length, flags ? flags.includes("u") : false);
+                            if (flags) {
+                                RegExpValidatorInstance.validateFlags(flags);
+                            }
+                        } catch {
+                            noFix = true;
+                        }
+
+                        const tokenBefore = sourceCode.getTokenBefore(node);
+
+                        if (tokenBefore && !validPrecedingTokens.includes(tokenBefore.value)) {
+                            noFix = true;
+                        }
+
+                        if (!/^[-a-zA-Z0-9\\[\](){} \t\r\n\v\f!@#$%^&*+^_=/~`.><?,'"|:;]*$/u.test(regexContent)) {
+                            noFix = true;
+                        }
+
+                        if (regexContent && !noFix) {
+                            let charIncrease = 0;
+
+                            const ast = new RegExpParser({ ecmaVersion: regexppEcmaVersion }).parsePattern(regexContent, 0, regexContent.length, flags ? flags.includes("u") : false);
+
+                            visitRegExpAST(ast, {
+                                onCharacterEnter(characterNode) {
+                                    let stringCodePointValue = String.fromCodePoint(characterNode.value);
+                                    const escaped = resolveEscapes(characterNode.raw);
+
+                                    if (escaped) {
+                                        stringCodePointValue = escaped;
+                                        regexContent =
+                                            regexContent.slice(0, characterNode.start + charIncrease) +
+                                            stringCodePointValue +
+                                            regexContent.slice(characterNode.end + charIncrease);
+
+                                        if (characterNode.raw.length === 1) {
+                                            charIncrease += 1;
+                                        }
+                                    }
+                                }
+                            });
+                        }
+
+                        const newRegExpValue = `/${regexContent || "(?:)"}/${flags || ""}`;
+
+                        context.report({
+                            node,
+                            messageId: "unexpectedRegExp",
+                            suggest: noFix ? [] : [{
+                                messageId: "unexpectedRegExp",
+                                fix(fixer) {
+                                    const tokenAfter = sourceCode.getTokenAfter(node);
+
+                                    return fixer.replaceTextRange(
+                                        node.range,
+                                        (tokenBefore && !canTokensBeAdjacent(tokenBefore, newRegExpValue) && /\S/u.test(text[node.range[0] - 1]) ? " " : "") +
+                                            newRegExpValue +
+                                            (tokenAfter && !canTokensBeAdjacent(newRegExpValue, tokenAfter) && /\S/u.test(text[node.range[1]]) ? " " : "")
+                                    );
+                                }
+                            }]
+                        });
                     }
                 }
             }