feat: make no-misleading-character-class report more granular errors

lib/rules/no-misleading-character-class.js

@@ -8,6 +8,7 @@ const { RegExpParser, visitRegExpAST } = require("@eslint-community/regexpp");
 const { isCombiningCharacter, isEmojiModifier, isRegionalIndicatorSymbol, isSurrogatePair } = require("./utils/unicode");
 const astUtils = require("./utils/ast-utils.js");
 const { isValidWithUnicodeFlag } = require("./utils/regular-expressions");
+const { parseStringLiteral, parseTemplateToken } = require("char-source");
 
 //------------------------------------------------------------------------------
 // Helpers
@@ -227,59 +228,61 @@ module.exports = {
         const parser = new RegExpParser();
 
         /**
-         * Generates a granular loc for context.report, if directly calculable.
-         * @param {Character[]} chars Individual characters being reported on.
+         * Creates a function used to generate locs for a specified node.
          * @param {Node} node Parent string node to report within.
-         * @returns {Object | null} Granular loc for context.report, if directly calculable.
-         * @see https://github.com/eslint/eslint/pull/17515
+         * @returns {(matches: Character[][]) => Location[]} A function to generate locs for the node.
          */
-        function generateReportLocation(chars, node) {
+        function createReportLocationGenerator(node) {
 
-            // Limit to to literals and expression-less templates with raw values === their value.
-            switch (node.type) {
-                case "TemplateLiteral":
-                    if (node.expressions.length || sourceCode.getText(node).slice(1, -1) !== node.quasis[0].value.cooked) {
-                        return null;
-                    }
-                    break;
-
-                case "Literal":
-                    if (typeof node.value === "string" && node.value !== node.raw.slice(1, -1)) {
-                        return null;
-                    }
-                    break;
-
-                default:
-                    return null;
+            // Only literals and expression-less templates generate granular errors.
+            if (!(node.type === "TemplateLiteral" && !node.expressions.length || node.type === "Literal")) {
+                return matches => (matches.length ? [node.loc] : []);
             }
 
-            return {
-                start: sourceCode.getLocFromIndex(node.range[0] + 1 + chars[0].start),
-                end: sourceCode.getLocFromIndex(node.range[0] + 1 + chars.at(-1).end)
-            };
-        }
-
-        /**
-         * Finds the report loc(s) for a range of matches.
-         * @param {Character[][]} matches Characters that should trigger a report.
-         * @param {Node} node The node to report.
-         * @returns {Object | null} Node loc(s) for context.report.
-         */
-        function getNodeReportLocations(matches, node) {
-            const locs = [];
-
-            for (const chars of matches) {
-                const loc = generateReportLocation(chars, node);
-
-                // If a report can't match to a range, don't report any others
-                if (!loc) {
-                    return [node.loc];
-                }
+            let charInfos = null;
+
+            /**
+             * Generates a granular loc for context.report.
+             * @param {Character[][]} matches Lists of individual characters being reported on.
+             * @returns {Location[]} Granular locs for context.report.
+             * @see https://github.com/eslint/eslint/pull/17515
+             */
+            function generateReportLocation(matches) {
+                return matches.map(chars => {
+                    const firstIndex = chars[0].start;
+                    const lastIndex = chars.at(-1).end - 1;
+                    let start;
+                    let end;
+
+                    if (node.type === "TemplateLiteral") {
+                        const source = sourceCode.getText(node);
+                        const offset = node.range[0];
+
+                        charInfos ??= parseTemplateToken(source);
+                        start = offset + charInfos[firstIndex].start;
+                        end = offset + charInfos[lastIndex].end;
+                    } else if (typeof node.value === "string") { // String Literal
+                        const source = node.raw;
+                        const offset = node.range[0];
+
+                        charInfos ??= parseStringLiteral(source);
+                        start = offset + charInfos[firstIndex].start;
+                        end = offset + charInfos[lastIndex].end;
+                    } else { // RegExp Literal
+                        const offset = node.range[0] + 1; // Add 1 to skip the leading slash.
+
+                        start = offset + firstIndex;
+                        end = offset + lastIndex + 1;
+                    }
 
-                locs.push(loc);
+                    return {
+                        start: sourceCode.getLocFromIndex(start),
+                        end: sourceCode.getLocFromIndex(end)
+                    };
+                });
             }
 
-            return locs;
+            return generateReportLocation;
         }
 
         /**
@@ -320,12 +323,13 @@ module.exports = {
                             } else {
                                 foundKindMatches.set(kind, [...findCharacterSequences[kind](chars)]);
                             }
-
                         }
                     }
                 }
             });
 
+            const generateReportLocation = createReportLocationGenerator(node);
+
             for (const [kind, matches] of foundKindMatches) {
                 let suggest;
 
@@ -336,7 +340,7 @@ module.exports = {
                     }];
                 }
 
-                const locs = getNodeReportLocations(matches, node);
+                const locs = generateReportLocation(matches);
 
                 for (const loc of locs) {
                     context.report({

package.json

@@ -72,6 +72,7 @@
     "@nodelib/fs.walk": "^1.2.8",
     "ajv": "^6.12.4",
     "chalk": "^4.0.0",
+    "char-source": "^0.0.0",
     "cross-spawn": "^7.0.2",
     "debug": "^4.3.2",
     "escape-string-regexp": "^4.0.0",