v8.0.0-alpha.0

Super early pre-release of Babel 8 :)

It's currently known to not work with:

• @babel/cli - see #15803
• babel-loader - see #15804

It is known to work with:

• @rollup/plugin-babel

peerDependencies are all incorrect, so use the npm flag --legacy-peer-deps if you want to test it.

For the full Babel 8 migration guide, see https://next.babeljs.io/docs/v8-migration

v8.0.0-alpha.0 (2023-07-20)

👓 Spec Compliance

• babel-parser
  • #12451 [babel 8] Report a SyntaxError for } and > in JSX text (@nicolo-ribaudo)
  • #12447 [babel 8] Disallow sequence expressions in JSX expression containers (@nicolo-ribaudo)

💥 Breaking Change

• Other
  • #15763 [babel 8] Bump eslint-parser/plugin eslint requirements (@JLHwung)
  • #13921 [babel 8] Align allow* parser options with ESLint behavior (@nicolo-ribaudo)
• All packages
  • #15585 [babel 8] Require Node.js ^16.20.0 || ^18.16.0 || >=20.0.0 (@nicolo-ribaudo)
  • #14013 [babel 8] Add "exports" to every package (@nicolo-ribaudo)
• babel-plugin-proposal-decorators, babel-plugin-proposal-pipeline-operator, babel-plugin-transform-class-properties
  • #15676 [babel 8] Only support legacy and 2023-05 decorators (@nicolo-ribaudo)
• babel-core, babel-helper-create-class-features-plugin, babel-plugin-transform-arrow-functions, babel-plugin-transform-computed-properties, babel-plugin-transform-for-of, babel-plugin-transform-regenerator, babel-plugin-transform-unicode-escapes, babel-preset-env, babel-traverse, babel-types
  • #15576 [babel 8] Other Babel 8 misc changes (@nicolo-ribaudo)
• babel-core, babel-helper-builder-binary-assignment-operator-visitor, babel-helper-create-class-features-plugin, babel-helper-create-regexp-features-plugin, babel-helper-environment-visitor, babel-helper-member-expression-to-functions, babel-helper-module-transforms, babel-helper-plugin-utils, babel-helper-replace-supers, babel-helper-simple-access, babel-helper-string-parser, babel-helper-transform-fixture-test-runner, babel-helpers, babel-plugin-transform-modules-commonjs, babel-preset-env
  • #15550 More misc Babel 8 little changes (@nicolo-ribaudo)
• babel-cli, babel-compat-data, babel-core, babel-helper-create-class-features-plugin, babel-helper-environment-visitor, babel-helper-replace-supers, babel-helpers, babel-parser, babel-plugin-transform-for-of, babel-plugin-transform-react-jsx, babel-preset-env, babel-traverse, babel-types
  • #15068 Babel 8 misc changes (@JLHwung)
• babel-types
  • #15527 [babel 8] Remove builders present only for backwards-compatibility (@nicolo-ribaudo)
  • #14464 [babel 8] Remove selfClosing from jsxElement builder (@wjw99830)
• babel-core, babel-plugin-syntax-flow, babel-plugin-syntax-jsx, babel-plugin-syntax-typescript, babel-plugin-transform-parameters, babel-plugin-transform-react-jsx-development, babel-plugin-transform-spread, babel-plugin-transform-typescript, babel-preset-flow, babel-preset-typescript, babel-standalone
  • #14955 [babel 8] Better file ext handling for TS and Flow presets (@nicolo-ribaudo)
• babel-traverse
  • #15288 [babel 8] Remove block argument from Scope#rename (@nicolo-ribaudo)
• babel-generator, babel-helper-compilation-targets, babel-preset-env, babel-preset-flow, babel-types
  • #14179 Bundle most packages in Babel 8 (@JLHwung)
• babel-generator, babel-helper-builder-binary-assignment-operator-visitor, babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-helper-skip-transparent-expression-wrappers, babel-plugin-proposal-function-bind, babel-plugin-proposal-logical-assignment-operators, babel-plugin-proposal-optional-chaining, babel-plugin-proposal-partial-application, babel-plugin-transform-proto-to-assign, babel-plugin-transform-spread, babel-traverse, babel-types
  • #14750 Remove Super from Expression alias (@JLHwung)
• babel-core, babel-generator, babel-helper-create-class-features-plugin, babel-plugin-proposal-class-properties, babel-plugin-proposal-decorators, babel-plugin-proposal-pipeline-operator, babel-plugin-syntax-decorators, babel-plugin-transform-function-name, babel-plugin-transform-typescript, babel-standalone
  • #12712 [babel 8] Remove support for the 2018-09 decorators proposal (@nicolo-ribaudo)
• babel-core, babel-helper-module-imports, babel-helper-transform-fixture-test-runner, babel-node, babel-plugin-proposal-class-static-block, babel-plugin-syntax-decorators, babel-plugin-transform-modules-commonjs, babel-plugin-transform-runtime, babel-standalone
  • #12695 [babel 8] Disallow synchronous usage of babel.* callback methods (@JLHwung)
• babel-generator, babel-types
  • #14465 [babel 8] ObjectTypeAnnotation fields must always be arrays (@danez)
  • #12361 [babel 8] Remove the Noop node type (@sidntrivedi012)
• babel-generator, babel-parser, babel-types
  • #13709 [babel 8] fix properties name for function-like TS nodes (@sosukesuzuki)
  • #12829 [babel 8] Use an identifier for TSTypeParameter.name (@fedeci)
• babel-node, babel-register
  • #14025 [babel 8] Move @babel/register transform to a separate worker (@nicolo-ribaudo)
• babel-parser
  • #13919 Improve template tokenizing (@JLHwung)
  • #13752 [babel 8] Materialize ESTree's classFeatures option (@nicolo-ribaudo)
• babel-plugin-transform-react-constant-elements, babel-preset-env
  • #13866 [babel 8] Enable preset-env bugfixes by default (@JLHwung)
• babel-core
  • #13199 [babel 8] Move ESLint parsing to a Worker (@nicolo-ribaudo)
• babel-generator, babel-parser
  • #13308 [Babel 8]: remove module attributes parser/generator support (@JLHwung)
  • #12608 [babel 8] Don't create TSParenthesizedType nodes by default (@JLHwung)
• babel-plugin-transform-block-scoping, babel-traverse
  • #13291 [babel 8] Do not skip requeued paths (@JLHwung)
• babel-cli, babel-core, babel-helper-module-transforms, babel-plugin-transform-modules-amd, babel-plugin-transform-modules-systemjs, babel-plugin-transform-modules-umd
  • #12724 [babel 8] Remove module-specific options from @babel/core (@nicolo-ribaudo)
• babel-preset-react
  • #12741 [babel 8] Type checking preset-react options (@JLHwung)
• babel-preset-flow
  • #12751 [babel 8] type checking preset-flow options (@JLHwung)
• babel-core, babel-helper-compilation-targets, babel-plugin-proposal-async-generator-functions, babel-plugin-proposal-class-properties, babel-plugin-proposal-decorators, babel-plugin-proposal-object-rest-spread, babel-plugin-transform-classes, babel-plugin-transform-flow-comments, babel-plugin-transform-flow-strip-types, babel-plugin-transform-function-name, babel-plugin-transform-modules-commonjs, babel-plugin-transform-parameters, babel-plugin-transform-react-constant-elements, babel-plugin-transform-regenerator, babel-plugin-transform-runtime, babel-preset-env, babel-standalone
  • #12989 breaking: fallback targets to "defaults, not ie 11" (@JLHwung)
• babel-plugin-proposal-dynamic-import, babel-plugin-transform-modules-systemjs
  • #12700 Require @babel/plugin-proposal-dynamic-import when transforming import() to SystemJS (@JLHwung)
• babel-generator, babel-plugin-transform-react-jsx, babel-plugin-transform-template-literals, babel-plugin-transform-unicode-escapes
  • #12675 [babel 8] Output minimal strings by default (@JLHwung)
• babel-code-frame, babel-highlight
  • #12660 [babel 8] Improve syntax highlighting (@nicolo-ribaudo)
• babel-node, babel-plugin-transform-async-to-generator, babel-plugin-transform-block-scoping, babel-plugin-transform-classes, babel-plugin-transform-function-name, babel-plugin-transform-react-constant-elements, babel-plugin-transform-react-inline-elements, babel-plugin-transform-react-jsx, babel-plugin-transform-regenerator, babel-preset-react, babel-preset-typescript, babel-standalone
  • #12630 [babel 8] Use the JSX automatic runtime by default (@nicolo-ribaudo)
• babel-helper-builder-react-jsx, babel-plugin-transform-react-jsx-development, babel-plugin-transform-react-jsx, babel-preset-react
  • #12593 [babel 8] Remove useSpread and useBuiltIns jsx options (@nicolo-ribaudo)
• babel-preset-env
  • #12594 [babel 8] Remove uglify target support in preset-env (@nicolo-ribaudo)
• babel-plugin-proposal-class-properties, babel-plugin-transform-typescript, babel-preset-typescript
  • #12461 [babel 8] Enable allowDeclareFields option by default with TS (@nicolo-ribaudo)
• babel-preset-typescript
  • #12460 Type checking preset-typescript options (@JLHwung)
• babel-generator
  • #12477 [babel 8] Remove the jsonCompatibleStrings option (@nicolo-ribaudo)
• babel-helper-fixtures, babel-plugin-transform-flow-strip-types
  • #12457 [babel 8] Enable allowDeclareFields option by default w/ Flow (@nicolo-ribaudo)

🚀 New Feature

• babel-helper-compilation-targets
  • #15551 use browserslist's defaults as default targets (@JLHwung)

🐛 Bug Fix

• babel-helper-fixtures, babel-preset-typescript
  • #15562 [Babel 8] fix ignoreExtensions behaviour (@JLHwung)

🏠 Internal

• babel-plugin-transform-runtime
  • #15528 [babel 8] regeneratorRuntime helper is always available (@nicolo-ribaudo)
• babel-core
  • #15526 [babel 8] Remove old error plugin mappings for default syntax (@nicolo-ribaudo)
• Other
  • #14949 Fix prepublish build of Babel 8 with ESM (@nicolo-ribaudo)
  • #14872 Use the built-in class fields and private methods rules in ESLint 8 (@JLHwung)
• babel-plugin-transform-modules-commonjs, babel-plugin-transform-runtime
  • #14120 [babel 8] Remove @babel/runtime@<=7.13.0 compat check (@nicolo-ribaudo)
• babel-cli
  • #14119 [babel 8] Remove @nicolo-ribaudo/chokidar-2 fallback (@nicolo-ribaudo)
• babel-cli, babel-node, babel-plugin-transform-runtime, babel-register
  • #13828 [babel 8] Remove make-dir polyfill for fs.mkdirSync (@nicolo-ribaudo)
  • #12458 Use native Node.js functions when available (@nicolo-ribaudo)
• babel-parser
  • #13768 Store token type as number (@JLHwung)
  • #13294 fix(parser): [Babel8] Align error codes between Flow and TypeScript (@sosukesuzuki)
• babel-plugin-proposal-partial-application, babel-types
  • #13407 [Babel 8] Remove optional field from MemberExpression (@danez)
• babel-core, babel-helper-transform-fixture-test-runner, babel-register
  • #12677 [babel 8] Replace lodash/escapeRegExp with escape-string-regexp (@hzoo)
• babel-cli, babel-plugin-transform-classes, babel-register, babel-traverse
  • #12656 [babel 8] Update globals, find-cache-dir and slash (@nicolo-ribaudo)
• babel-plugin-syntax-typescript
  • #12607 chore: do not push objectRestSpread parser option in Babel 8 (@JLHwung)