create project

kitabcitab/node_modules/eslint/lib/rules/prefer-regex-literals.js

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+/**
+ * @fileoverview Rule to disallow use of the `RegExp` constructor in favor of regular expression literals
+ * @author Milos Djermanovic
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+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
+//------------------------------------------------------------------------------
+
+const REGEXPP_LATEST_ECMA_VERSION = 2022;
+
+/**
+ * Determines whether the given node is a string literal.
+ * @param {ASTNode} node Node to check.
+ * @returns {boolean} True if the node is a string literal.
+ */
+function isStringLiteral(node) {
+    return node.type === "Literal" && typeof node.value === "string";
+}
+
+/**
+ * Determines whether the given node is a regex literal.
+ * @param {ASTNode} node Node to check.
+ * @returns {boolean} True if the node is a regex literal.
+ */
+function isRegexLiteral(node) {
+    return node.type === "Literal" && Object.prototype.hasOwnProperty.call(node, "regex");
+}
+
+/**
+ * Determines whether the given node is a template literal without expressions.
+ * @param {ASTNode} node Node to check.
+ * @returns {boolean} True if the node is a template literal without expressions.
+ */
+function isStaticTemplateLiteral(node) {
+    return node.type === "TemplateLiteral" && node.expressions.length === 0;
+}
+
+const validPrecedingTokens = new Set([
+    "(",
+    ";",
+    "[",
+    ",",
+    "=",
+    "+",
+    "*",
+    "-",
+    "?",
+    "~",
+    "%",
+    "**",
+    "!",
+    "typeof",
+    "instanceof",
+    "&&",
+    "||",
+    "??",
+    "return",
+    "...",
+    "delete",
+    "void",
+    "in",
+    "<",
+    ">",
+    "<=",
+    ">=",
+    "==",
+    "===",
+    "!=",
+    "!==",
+    "<<",
+    ">>",
+    ">>>",
+    "&",
+    "|",
+    "^",
+    ":",
+    "{",
+    "=>",
+    "*=",
+    "<<=",
+    ">>=",
+    ">>>=",
+    "^=",
+    "|=",
+    "&=",
+    "??=",
+    "||=",
+    "&&=",
+    "**=",
+    "+=",
+    "-=",
+    "/=",
+    "%=",
+    "/",
+    "do",
+    "break",
+    "continue",
+    "debugger",
+    "case",
+    "throw"
+]);
+
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/** @type {import('../shared/types').Rule} */
+module.exports = {
+    meta: {
+        type: "suggestion",
+
+        docs: {
+            description: "Disallow use of the `RegExp` constructor in favor of regular expression literals",
+            recommended: false,
+            url: "https://eslint.org/docs/rules/prefer-regex-literals"
+        },
+
+        hasSuggestions: true,
+
+        schema: [
+            {
+                type: "object",
+                properties: {
+                    disallowRedundantWrapping: {
+                        type: "boolean",
+                        default: false
+                    }
+                },
+                additionalProperties: false
+            }
+        ],
+
+        messages: {
+            unexpectedRegExp: "Use a regular expression literal instead of the 'RegExp' constructor.",
+            replaceWithLiteral: "Replace with an equivalent regular expression literal.",
+            unexpectedRedundantRegExp: "Regular expression literal is unnecessarily wrapped within a 'RegExp' constructor.",
+            unexpectedRedundantRegExpWithFlags: "Use regular expression literal with flags instead of the 'RegExp' constructor."
+        }
+    },
+
+    create(context) {
+        const [{ disallowRedundantWrapping = false } = {}] = context.options;
+        const sourceCode = context.getSourceCode();
+
+        /**
+         * Determines whether the given identifier node is a reference to a global variable.
+         * @param {ASTNode} node `Identifier` node to check.
+         * @returns {boolean} True if the identifier is a reference to a global variable.
+         */
+        function isGlobalReference(node) {
+            const scope = context.getScope();
+            const variable = findVariable(scope, node);
+
+            return variable !== null && variable.scope.type === "global" && variable.defs.length === 0;
+        }
+
+        /**
+         * Determines whether the given node is a String.raw`` tagged template expression
+         * with a static template literal.
+         * @param {ASTNode} node Node to check.
+         * @returns {boolean} True if the node is String.raw`` with a static template.
+         */
+        function isStringRawTaggedStaticTemplateLiteral(node) {
+            return node.type === "TaggedTemplateExpression" &&
+                astUtils.isSpecificMemberAccess(node.tag, "String", "raw") &&
+                isGlobalReference(astUtils.skipChainExpression(node.tag).object) &&
+                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.
+         * @returns {boolean} True if the node is a static string.
+         */
+        function isStaticString(node) {
+            return isStringLiteral(node) ||
+                isStaticTemplateLiteral(node) ||
+                isStringRawTaggedStaticTemplateLiteral(node);
+        }
+
+        /**
+         * Determines whether the relevant arguments of the given are all static string literals.
+         * @param {ASTNode} node Node to check.
+         * @returns {boolean} True if all arguments are static strings.
+         */
+        function hasOnlyStaticStringArguments(node) {
+            const args = node.arguments;
+
+            if ((args.length === 1 || args.length === 2) && args.every(isStaticString)) {
+                return true;
+            }
+
+            return false;
+        }
+
+        /**
+         * Determines whether the arguments of the given node indicate that a regex literal is unnecessarily wrapped.
+         * @param {ASTNode} node Node to check.
+         * @returns {boolean} True if the node already contains a regex literal argument.
+         */
+        function isUnnecessarilyWrappedRegexLiteral(node) {
+            const args = node.arguments;
+
+            if (args.length === 1 && isRegexLiteral(args[0])) {
+                return true;
+            }
+
+            if (args.length === 2 && isRegexLiteral(args[0]) && isStaticString(args[1])) {
+                return true;
+            }
+
+            return false;
+        }
+
+        /**
+         * Returns a ecmaVersion compatible for regexpp.
+         * @param {number} ecmaVersion The ecmaVersion to convert.
+         * @returns {import("regexpp/ecma-versions").EcmaVersion} The resulting ecmaVersion compatible for regexpp.
+         */
+        function getRegexppEcmaVersion(ecmaVersion) {
+            if (ecmaVersion <= 5) {
+                return 5;
+            }
+            return Math.min(ecmaVersion, REGEXPP_LATEST_ECMA_VERSION);
+        }
+
+        /**
+         * 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();
+                const tracker = new ReferenceTracker(scope);
+                const traceMap = {
+                    RegExp: {
+                        [CALL]: true,
+                        [CONSTRUCT]: true
+                    }
+                };
+
+                for (const { node } of tracker.iterateGlobalReferences(traceMap)) {
+                    if (disallowRedundantWrapping && isUnnecessarilyWrappedRegexLiteral(node)) {
+                        if (node.arguments.length === 2) {
+                            context.report({ node, messageId: "unexpectedRedundantRegExpWithFlags" });
+                        } else {
+                            context.report({ node, messageId: "unexpectedRedundantRegExp" });
+                        }
+                    } else if (hasOnlyStaticStringArguments(node)) {
+                        let regexContent = getStringValue(node.arguments[0]);
+                        let noFix = false;
+                        let flags;
+
+                        if (node.arguments[1]) {
+                            flags = getStringValue(node.arguments[1]);
+                        }
+
+                        const regexppEcmaVersion = getRegexppEcmaVersion(context.languageOptions.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.has(tokenBefore.value)) {
+                            noFix = true;
+                        }
+
+                        if (!/^[-a-zA-Z0-9\\[\](){} \t\r\n\v\f!@#$%^&*+^_=/~`.><?,'"|:;]*$/u.test(regexContent)) {
+                            noFix = true;
+                        }
+
+                        if (sourceCode.getCommentsInside(node).length > 0) {
+                            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) {
+                                    const escaped = resolveEscapes(characterNode.raw);
+
+                                    if (escaped) {
+                                        regexContent =
+                                            regexContent.slice(0, characterNode.start + charIncrease) +
+                                            escaped +
+                                            regexContent.slice(characterNode.end + charIncrease);
+
+                                        if (characterNode.raw.length === 1) {
+                                            charIncrease += 1;
+                                        }
+                                    }
+                                }
+                            });
+                        }
+
+                        const newRegExpValue = `/${regexContent || "(?:)"}/${flags || ""}`;
+
+                        context.report({
+                            node,
+                            messageId: "unexpectedRegExp",
+                            suggest: noFix ? [] : [{
+                                messageId: "replaceWithLiteral",
+                                fix(fixer) {
+                                    const tokenAfter = sourceCode.getTokenAfter(node);
+
+                                    return fixer.replaceText(
+                                        node,
+                                        (tokenBefore && !canTokensBeAdjacent(tokenBefore, newRegExpValue) && tokenBefore.range[1] === node.range[0] ? " " : "") +
+                                            newRegExpValue +
+                                            (tokenAfter && !canTokensBeAdjacent(newRegExpValue, tokenAfter) && node.range[1] === tokenAfter.range[0] ? " " : "")
+                                    );
+                                }
+                            }]
+                        });
+                    }
+                }
+            }
+        };
+    }
+};