@babel/runtime-corejs2

:eyeglasses: Spec Compliance

• babel-parser

  • Disallow await inside async arrow params (@nicolo-ribaudo)

  • [parser] Disallow numeric separators in legacy octal like integers (@gonzarodriguezt)

:rocket: New Feature

• babel-types

  • Add declarations for more of @babel/types exports (@Jessidhia)

:bug: Bug Fix

• babel-plugin-transform-block-scoping

  • Do not remove let bindings even they are wrapped in closure (@JLHwung)

• babel-parser

  • add scope to TSModuleDeclaration (@tanhauhau)

  • Do not allow member expressions to start async arrows (@nicolo-ribaudo)

  • [parser] Don't crash on comment after trailing comma after elision (@nicolo-ribaudo)

• babel-plugin-transform-react-constant-elements, babel-traverse

  • Do not hoist jsx referencing a mutable binding (@nicolo-ribaudo)

• babel-generator, babel-parser, babel-plugin-transform-block-scoping, babel-plugin-transform-flow-comments, babel-plugin-transform-flow-strip-types, babel-plugin-transform-typescript

  • Flow: interface identifier should be declared in the scope (@JLHwung)

:nail_care: Polish

• babel-core

  • assertNoDuplicates throw with more context (@hjdivad)

  • Add filename to transform error (@JLHwung)

:house: Internal

• Other

  • Use make -j for parallel build (@JLHwung)

  • perf: only apply lazy cjs module transform on cli and core (@JLHwung)

  • Enable optional chaining and nullish coalescing plugins (@nicolo-ribaudo)

• babel-cli, babel-core, babel-generator, babel-helper-fixtures, babel-helper-transform-fixture-test-runner, babel-node, babel-plugin-transform-react-jsx-source, babel-plugin-transform-runtime, babel-preset-env, babel-preset-react

  • Add windows to travis (@nicolo-ribaudo)

:running_woman: Performance

• babel-parser

  • perf: replace lookahead by lookaheadCharCode (@JLHwung)

• Other

  • perf: only apply lazy cjs module transform on cli and core (@JLHwung)