refactor: switch to eslint v9, eslint-config-eslint v10 (#604)

eslint.config.js

@@ -23,11 +23,7 @@ export default [
  files: ["tools/**"],
  rules: {
  "no-console": "off",
- "n/no-process-exit": "off",
- "n/no-unsupported-features/es-syntax": ["error", {
- version: ">=16.0.0",
- ignores: ["modules"]
- }]
+ "n/no-process-exit": "off"
  }
  }
 ];

espree.js

@@ -1,5 +1,3 @@
-/* eslint-disable jsdoc/no-multi-asterisks -- needed to preserve original formatting of licences */
-
 /**
  * @fileoverview Main Espree file that converts Acorn into Esprima output.
  *
@@ -57,7 +55,6 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/* eslint-enable jsdoc/no-multi-asterisks -- needed to preserve original formatting of licences */
 
 import * as acorn from "acorn";
 import jsx from "acorn-jsx";
@@ -160,7 +157,7 @@ export const Syntax = (function() {
  }
 
  for (key in VisitorKeys) {
- if (Object.hasOwnProperty.call(VisitorKeys, key)) {
+ if (Object.hasOwn(VisitorKeys, key)) {
  types[key] = key;
  }
  }

lib/options.js

@@ -27,7 +27,7 @@ const SUPPORTED_VERSIONS = [
  * @returns {number} The latest ECMAScript version.
  */
 export function getLatestEcmaVersion() {
- return SUPPORTED_VERSIONS[SUPPORTED_VERSIONS.length - 1];
+ return SUPPORTED_VERSIONS.at(-1);
 }
 
 /**

lib/token-translator.js

@@ -40,7 +40,7 @@ const Token = {
  */
 function convertTemplatePart(tokens, code) {
  const firstToken = tokens[0],
- lastTemplateToken = tokens[tokens.length - 1];
+ lastTemplateToken = tokens.at(-1);
 
  const token = {
  type: Token.Template,

package.json

@@ -42,11 +42,11 @@
  "@rollup/plugin-node-resolve": "^11.2.0",
  "c8": "^7.11.0",
  "chai": "^4.3.6",
- "eslint": "^8.44.0",
- "eslint-config-eslint": "^9.0.0",
+ "eslint": "^9.1.1",
+ "eslint-config-eslint": "^10.0.0",
  "eslint-release": "^3.2.0",
  "esprima-fb": "^8001.2001.0-dev-harmony-fb",
- "globals": "^13.20.0",
+ "globals": "^15.1.0",
  "lint-staged": "^13.2.0",
  "mocha": "^9.2.2",
  "npm-run-all": "^4.1.5",
@@ -70,7 +70,7 @@
  "build:debug": "npm run build -- -m",
  "build:docs": "node tools/sync-docs.js",
  "build:update-version": "node tools/update-version.js",
- "lint": "eslint . --report-unused-disable-directives",
+ "lint": "eslint .",
  "lint:fix": "npm run lint -- --fix",
  "prepublishOnly": "npm run build:update-version && npm run build",
  "pretest": "npm run build",

tools/create-test.js

@@ -89,7 +89,7 @@ code.forEach((source, index) => {
  sourceCode = source.trim();
 
  // add an extra semicolon if there's not already one at the end - helps normalize empty lines at end of input
- if (sourceCode[sourceCode.length - 1] !== ";") {
+ if (sourceCode.at(-1) !== ";") {
  sourceCode += ";";
  }
 

tools/update-tests.js

@@ -70,14 +70,13 @@ const testFiles = getTestFilenames(FIXTURES_DIR),
 libraryFiles.forEach(filename => {
  const testResultFilename = `${path.resolve(__dirname, "..", LIBRARIES_DIR, filename)}.result.json`,
  code = shelljs.cat(path.resolve(LIBRARIES_DIR, filename));
- let result = tester.getExpectedResult(code, {
+ const result = tester.getExpectedResult(code, {
  loc: true,
  range: true,
  tokens: true
  });
 
  JSON.stringify(result).to(testResultFilename);
- result = null;
 });
 
 // update all tests in ecma-features