Use eslint v9 (#16479)

* update

* skip old eslint

* review

* compat

Makefile.source.mjs

@@ -336,7 +336,6 @@ target["clone-license"] = function () {
  */
 
 function eslint(...extraArgs) {
- const eslintEnv = { BABEL_ENV: "test" };
  const eslintArgs = ["--format", "codeframe", ...extraArgs.filter(Boolean)];
 
  const packagesPackages = readdirSync("packages").filter(n =>
@@ -361,10 +360,15 @@ function eslint(...extraArgs) {
 
  if (process.env.ESLINT_GO_BRRRR) {
  // Run as a single process. Needs a lot of memory (12GB).
- env(() => yarn(["eslint", "packages", ...rest, ...eslintArgs]), eslintEnv);
+ env(() => yarn(["eslint", "packages", ...rest, ...eslintArgs]), {
+ BABEL_ENV: "test",
+ NODE_OPTIONS: "--max-old-space-size=16384",
+ });
  } else {
  for (const chunk of chunks) {
- env(() => yarn(["eslint", ...chunk, ...eslintArgs]), eslintEnv);
+ env(() => yarn(["eslint", ...chunk, ...eslintArgs]), {
+ BABEL_ENV: "test",
+ });
  }
  }
 }

eslint.config.js

@@ -65,7 +65,7 @@ module.exports = [
  {
  plugins: {
  import: pluginImport,
- node: pluginN,
+ n: pluginN,
  prettier: pluginPrettier,
  "@babel/development": pluginBabelDevelopment,
  "@babel/development-internal": pluginBabelDevelopmentInternal,
@@ -85,7 +85,10 @@ module.exports = [
  parser: typescriptEslint.parser,
  parserOptions: {
  allowAutomaticSingleRunInference: true,
- EXPERIMENTAL_useProjectService: true,
+ // @ts-expect-error types are old
+ EXPERIMENTAL_useProjectService: {
+ maximumDefaultProjectFileMatchCount_THIS_WILL_SLOW_DOWN_LINTING: 1000,
+ },
  },
  },
  plugins: {
@@ -218,9 +221,9 @@ module.exports = [
  {
  files: testFiles,
  rules: {
- "node/no-unsupported-features": [
+ "n/no-unsupported-features/node-builtins": [
  "error",
- { version: "12.17.0", ignores: ["modules"] },
+ { version: "12.17.0", ignores: ["module"] },
  ],
  "@babel/development-internal/require-default-import-fallback": "error",
  "import/no-unresolved": "error",
@@ -281,12 +284,6 @@ module.exports = [
  ],
  },
  },
- {
- files: ["eslint/babel-eslint-parser/src/**/*.js"],
- rules: {
- "no-restricted-imports": ["error", "@babel/core"],
- },
- },
  {
  files: ["packages/babel-plugin-transform-runtime/scripts/**/*.js"],
  rules: {
@@ -306,7 +303,7 @@ module.exports = [
  },
  },
  {
- files: ["scripts/**/*.{js,cjs}"],
+ files: ["scripts/**/*.{js,cjs,mjs}"],
  rules: {
  "import/no-extraneous-dependencies": ["error", { packageDir: "." }],
  },

eslint/babel-eslint-config-internal/index.js

@@ -34,6 +34,7 @@ module.exports = [
  "no-confusing-arrow": "error",
  "no-empty": ["error", { allowEmptyCatch: true }],
  "no-process-exit": "error",
+ "no-unused-vars": ["error", { caughtErrors: "none" }],
  "no-var": "error",
  "prefer-const": "error",
  },

eslint/babel-eslint-parser/src/types.d.cts

@@ -3,7 +3,6 @@ import type { InputOptions } from "@babel/core";
 import type { Token as tokenizerToken } from "../../../packages/babel-parser/src/tokenizer";
 import type { ExportedTokenType } from "../../../packages/babel-parser/src/tokenizer/types";
 import type * as estree from "estree";
-// eslint-disable-next-line @typescript-eslint/consistent-type-imports
 import type {
  PatternVisitor,
  Reference,

eslint/babel-eslint-plugin-development-internal/src/rules/require-default-import-fallback.cjs

@@ -33,7 +33,9 @@ module.exports = {
  );
  if (!defaultSpecifier) return;
 
- const scope = ctx.getScope();
+ const scope = ctx.sourceCode
+ ? ctx.sourceCode.getScope(node)
+ : ctx.getScope();
 
  const { name: local } = defaultSpecifier.local;
  const { references } = scope.variables.find(v => v.name === local);

eslint/babel-eslint-plugin-development/src/rules/no-deprecated-clone.cjs

@@ -10,7 +10,9 @@ module.exports = {
  return {
  CallExpression(node) {
  const { callee } = node;
- const scope = context.getScope();
+ const scope = context.sourceCode
+ ? context.sourceCode.getScope(node)
+ : context.getScope();
 
  const origin = getReferenceOrigin(callee, scope);
  if (!origin) return;

eslint/babel-eslint-plugin-development/src/rules/no-undefined-identifier.cjs

@@ -17,7 +17,9 @@ module.exports = {
  return {
  CallExpression(node) {
  const { callee } = node;
- const scope = context.getScope();
+ const scope = context.sourceCode
+ ? context.sourceCode.getScope(node)
+ : context.getScope();
 
  const origin = getReferenceOrigin(callee, scope);
  if (!origin) return;

eslint/babel-eslint-plugin-development/src/rules/plugin-name.cjs

@@ -32,7 +32,16 @@ module.exports = {
  };
 
  function functionVisitor(node) {
- if (!isBabelPluginFactory(node, context.getScope())) return;
+ if (
+ !isBabelPluginFactory(
+ node,
+ context.sourceCode
+ ? context.sourceCode.getScope(node)
+ : context.getScope(),
+ )
+ ) {
+ return;
+ }
 
  const returnValue = getReturnValue(node);
  if (!returnValue || returnValue.type !== "ObjectExpression") return;

package.json

@@ -51,12 +51,12 @@
  "c8": "^8.0.1",
  "charcodes": "^0.2.0",
  "core-js": "^3.36.1",
- "eslint": "^8.57.0",
+ "eslint": "^9.2.0",
  "eslint-formatter-codeframe": "^7.32.1",
  "eslint-import-resolver-node": "^0.3.9",
  "eslint-plugin-import": "^2.29.1",
  "eslint-plugin-jest": "^27.9.0",
- "eslint-plugin-n": "^16.6.2",
+ "eslint-plugin-n": "^17.5.0",
  "eslint-plugin-prettier": "^5.1.3",
  "execa": "^8.0.1",
  "glob": "^10.3.10",
@@ -82,8 +82,8 @@
  "shelljs": "^0.8.5",
  "test262-stream": "^1.4.0",
  "through2": "^4.0.0",
- "typescript": "^5.4.2",
- "typescript-eslint": "^7.2.0"
+ "typescript": "^5.4.5",
+ "typescript-eslint": "^7.8.0"
  },
  "workspaces": [
  "codemods/*",

packages/babel-cli/src/babel/dir.ts

@@ -167,7 +167,6 @@ export default async function ({
  for (const filename of cliOptions.filenames) {
  // compiledFiles is just incremented without reading its value, so we
  // don't risk race conditions.
- // eslint-disable-next-line require-atomic-updates
  compiledFiles += await handle(filename);
  }
 

packages/babel-core/src/config/files/module-types.ts

@@ -195,7 +195,6 @@ const loadMjsDefault = endHiddenCallStack(async function loadMjsDefault(
 
 function getTSPreset(filepath: string) {
  try {
- // eslint-disable-next-line import/no-extraneous-dependencies
  return require("@babel/preset-typescript");
  } catch (error) {
  if (error.code !== "MODULE_NOT_FOUND") throw error;

packages/babel-core/src/errors/rewrite-stack-trace.ts

@@ -119,7 +119,6 @@ export function endHiddenCallStack<A extends unknown[], R>(
 
 function setupPrepareStackTrace() {
  // @ts-expect-error This function is a singleton
- // eslint-disable-next-line no-func-assign
  setupPrepareStackTrace = () => {};
 
  const { prepareStackTrace = defaultPrepareStackTrace } = Error;

packages/babel-helper-create-class-features-plugin/src/fields.ts

@@ -281,7 +281,7 @@ const privateNameVisitor = privateNameVisitorFactory<
  }
  const { name } = node.id;
  if (!privateNamesMap.has(name)) return;
- if (redeclared && redeclared.includes(name)) return;
+ if (redeclared?.includes(name)) return;
 
  this.handle(parentPath, noDocumentAll);
  },
@@ -333,7 +333,7 @@ const privateInVisitor = privateNameVisitorFactory<
  const { name } = left.id;
 
  if (!privateNamesMap.has(name)) return;
- if (redeclared && redeclared.includes(name)) return;
+ if (redeclared?.includes(name)) return;
 
  // if there are any local variable shadowing classRef, unshadow it
  // see #12960

packages/babel-helper-module-transforms/src/get-module-name.ts

@@ -15,7 +15,6 @@ if (!process.env.BABEL_8_BREAKING) {
  const originalGetModuleName = getModuleName;
 
  // @ts-expect-error TS doesn't like reassigning a function.
- // eslint-disable-next-line no-func-assign
  getModuleName = function getModuleName(
  rootOpts: RootOptions & PluginOptions,
  pluginOpts: PluginOptions,

packages/babel-helpers/src/helpers/typeof.js

@@ -1,7 +1,5 @@
 /* @minVersion 7.0.0-beta.0 */
 
-/* eslint-disable no-func-assign */
-
 export default function _typeof(obj) {
  "@babel/helpers - typeof";
 

packages/babel-helpers/src/helpers/usingCtx.ts

@@ -9,8 +9,7 @@ type Stack = {
 export default function _usingCtx() {
  var _disposeSuppressedError =
  typeof SuppressedError === "function"
- ? // eslint-disable-next-line no-undef
- SuppressedError
+ ? SuppressedError
  : (function (error: Error, suppressed: Error) {
  var err = new Error() as SuppressedError;
  err.name = "SuppressedError";

packages/babel-parser/src/parser/expression.ts

@@ -2652,7 +2652,6 @@ export default abstract class ExpressionParser extends LValParser {
  checkParams(
  node: Undone<N.Function>,
  allowDuplicates: boolean,
- // eslint-disable-next-line @typescript-eslint/no-unused-vars
  isArrowFunction?: boolean | null,
  strictModeChanged: boolean = true,
  ): void {

packages/babel-parser/src/parser/statement.ts

@@ -2397,7 +2397,6 @@ export default abstract class StatementParser extends ExpressionParser {
  this.unexpected(null, tt.braceL);
  }
 
- // eslint-disable-next-line @typescript-eslint/no-unused-vars
  eatExportStar(
  node: Undone<N.Node>,
  ): node is Undone<N.ExportNamedDeclaration | N.ExportAllDeclaration> {
@@ -3387,11 +3386,10 @@ export default abstract class StatementParser extends ExpressionParser {
  parseImportSpecifier(
  specifier: Undone<N.ImportSpecifier>,
  importedIsString: boolean,
- /* eslint-disable @typescript-eslint/no-unused-vars -- used in TypeScript and Flow parser */
+ /* used in TypeScript and Flow parser */
  isInTypeOnlyImport: boolean,
  isMaybeTypeOnly: boolean,
  bindingType: BindingFlag | undefined,
- /* eslint-enable @typescript-eslint/no-unused-vars */
  ): N.ImportSpecifier {
  if (this.eatContextual(tt._as)) {
  specifier.local = this.parseIdentifier();

packages/babel-parser/src/plugins/flow/index.ts

@@ -2205,7 +2205,6 @@ export default (superClass: typeof Parser) =>
 
  parseParenItem<T extends N.Expression | N.RestElement | N.SpreadElement>(
  node: T,
- // eslint-disable-next-line @typescript-eslint/no-unused-vars
  startLoc: Position,
  ): T | N.TypeCastExpression | N.TsTypeCastExpression {
  const newNode = super.parseParenItem(node, startLoc);
@@ -2444,7 +2443,6 @@ export default (superClass: typeof Parser) =>
  exprList:
  | ReadonlyArray<N.Expression | N.SpreadElement>
  | ReadonlyArray<N.Expression | N.RestElement>,
- // eslint-disable-next-line @typescript-eslint/no-unused-vars
  isParenthesizedExpr?: boolean,
  ):
  | ReadonlyArray<N.Expression | N.SpreadElement>

packages/babel-parser/src/plugins/placeholders.ts

@@ -35,8 +35,6 @@ const PlaceholderErrors = ParseErrorEnum`placeholders`({
  UnexpectedSpace: "Unexpected space in placeholder.",
 });
 
-/* eslint-disable sort-keys */
-
 export default (superClass: typeof Parser) =>
  class PlaceholdersParserMixin extends superClass implements Parser {
  parsePlaceholder<T extends PlaceholderTypes>(

packages/babel-parser/src/util/scopeflags.ts

@@ -1,5 +1,4 @@
 // Each scope gets a bitset that may contain these flags
-/* eslint-disable prettier/prettier */
 /* prettier-ignore */
 export const enum ScopeFlag {
  OTHER = 0b000000000,

packages/babel-parser/test/helpers/run-fixture-tests.js

@@ -118,7 +118,6 @@ function runParseTest(parse, test, onlyCompareErrors) {
  const optionsLocation = join(testLocation, "options.json");
 
  // We want to throw away the contents of `throws` here.
- // eslint-disable-next-line no-unused-vars
  const { throws: expectedThrows, ...oldOptions } = readJSON(optionsLocation);
  const newOptions = { ...oldOptions, ...(throws && { throws }) };
 
@@ -176,7 +175,7 @@ function runParseTest(parse, test, onlyCompareErrors) {
 function readJSON(filename) {
  try {
  return JSONParse(readFileSync(filename, "utf-8"));
- } catch (error) {
+ } catch {
  return {};
  }
 }

packages/babel-plugin-transform-react-constant-elements/src/index.ts

@@ -119,7 +119,7 @@ export default declare((api, options: Options) => {
  // Ignore constant bindings.
  if (path.isIdentifier()) {
  const binding = path.scope.getBinding(path.node.name);
- if (binding && binding.constant) return;
+ if (binding?.constant) return;
  }
 
  // If we allow mutable props, tags with function expressions can be

packages/babel-plugin-transform-runtime/scripts/build-dist.js

@@ -83,7 +83,6 @@ if (!bool(process.env.BABEL_8_BREAKING)) {
  corejsRoot: "core-js-pure/features",
  });
 
- // eslint-disable-next-line no-inner-declarations
  function writeCoreJS({
  corejs,
  proposals,
@@ -124,7 +123,6 @@ if (!bool(process.env.BABEL_8_BREAKING)) {
  writeCorejsExports(pkgDirname, runtimeRoot, paths);
  }
 
- // eslint-disable-next-line no-inner-declarations
  function writeCorejsExports(pkgDirname, runtimeRoot, paths) {
  const pkgJsonPath = require.resolve(`${pkgDirname}/package.json`);
  const pkgJson = require(pkgJsonPath);

packages/babel-traverse/src/path/family.ts

@@ -10,8 +10,8 @@ import {
 } from "@babel/types";
 import type * as t from "@babel/types";
 
-const NORMAL_COMPLETION = 0 as const;
-const BREAK_COMPLETION = 1 as const;
+const NORMAL_COMPLETION = 0;
+const BREAK_COMPLETION = 1;
 
 type Completion = {
  path: NodePath;
@@ -30,11 +30,11 @@ type CompletionContext = {
  shouldPopulateBreak: boolean;
 };
 
-function NormalCompletion(path: NodePath) {
+function NormalCompletion(path: NodePath): Completion {
  return { type: NORMAL_COMPLETION, path };
 }
 
-function BreakCompletion(path: NodePath) {
+function BreakCompletion(path: NodePath): Completion {
  return { type: BREAK_COMPLETION, path };
 }
 

packages/babel-traverse/src/scope/index.ts

@@ -440,7 +440,7 @@ export default class Scope {
  const shouldSkip = path.key === "key" || path.listKey === "decorators";
  path = path.parentPath;
  if (shouldSkip && path.isMethod()) path = path.parentPath;
- if (path && path.isScope()) parent = path;
+ if (path?.isScope()) parent = path;
  } while (path && !parent);
 
  return parent?.scope;

packages/babel-traverse/src/visitors.ts

@@ -138,7 +138,6 @@ export function explode<S>(visitor: Visitor<S>): ExplodedVisitor<S> {
  if (existing) {
  mergePair(existing, fns);
  } else {
- // @ts-expect-error Expression produces a union type that is too complex to represent.
  visitor[alias] = { ...fns };
  }
  }