The @babel/plugin-transform-block-scoped-functions npm package is designed to ensure that functions defined within blocks (such as if statements or for loops) are properly scoped to those blocks in environments that may not support this feature natively. This is particularly useful for ensuring compatibility with older browsers or JavaScript environments that do not fully implement ES6 scoping rules.

What are @babel/plugin-transform-block-scoped-functions's main functionalities?

Function Scoping

This feature ensures that functions defined within a block are scoped to that block. This is important for compatibility with ES6, where functions are block-scoped, unlike in ES5 where they are function-scoped. The plugin transforms the code to work correctly in environments that do not support block scoping natively.

"use strict";\n\nif (true) {\n  function foo() { return 1; }\n}\n\nfoo(); // Throws ReferenceError in ES6, transformed code works by scoping function within the block

Other packages similar to @babel/plugin-transform-block-scoped-functions

Changelog

Source

v7.18.6 (2022-06-27)

:eyeglasses: Spec Compliance

babel-parser
- #14650 [ts] Disallow property access after instantiation expression (@nicolo-ribaudo)
- #14636 [ts] Allow ...<...> followed by newline or binary operator (@nicolo-ribaudo)
babel-generator, babel-parser, babel-preset-env, babel-template
- #14668 JSON modules should be imported with default (@JLHwung)

:bug: Bug Fix

babel-helper-remap-async-to-generator, babel-plugin-proposal-async-generator-functions
- #14391 Transform await in computed class keys (@Yokubjon-J)
babel-plugin-transform-parameters
- #14694 fix: preserve function params type if possible (@magic-akari)
babel-core
- #14583 fix: Memory leak when deep cloning in babel-core (@liuxingbaoyu)
babel-core, babel-helper-check-duplicate-nodes, babel-plugin-bugfix-safari-id-destructuring-collision-in-function-expression, babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining, babel-plugin-proposal-destructuring-private, babel-plugin-proposal-optional-chaining, babel-plugin-transform-runtime
- #14663 Fix import { types } from "@babel/core" with native ESM (@nicolo-ribaudo)

:house: Internal

babel-standalone
- #14697 Add proposal-unicode-sets-regex to @babel/standalone (@nicolo-ribaudo)
Other
- #14687 chore: Update bench baselines (@liuxingbaoyu)
babel-generator, babel-types
- #14685 enable TS compiler option: strictBindCallApply (@JLHwung)
babel-code-frame, babel-core, babel-generator, babel-helper-annotate-as-pure, babel-helper-builder-binary-assignment-operator-visitor, babel-helper-builder-react-jsx, babel-helper-check-duplicate-nodes, babel-helper-compilation-targets, babel-helper-create-class-features-plugin, babel-helper-create-regexp-features-plugin, babel-helper-define-map, babel-helper-explode-assignable-expression, babel-helper-fixtures, babel-helper-function-name, babel-helper-hoist-variables, babel-helper-member-expression-to-functions, babel-helper-module-imports, babel-helper-module-transforms, babel-helper-optimise-call-expression, babel-helper-plugin-test-runner, babel-helper-plugin-utils, babel-helper-remap-async-to-generator, babel-helper-replace-supers, babel-helper-simple-access, babel-helper-split-export-declaration, babel-helper-transform-fixture-test-runner, babel-helper-validator-option, babel-helper-wrap-function, babel-helpers, babel-highlight, babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining, babel-plugin-external-helpers, babel-plugin-proposal-async-generator-functions, babel-plugin-proposal-class-static-block, babel-plugin-proposal-decorators, babel-plugin-proposal-destructuring-private, babel-plugin-proposal-function-bind, babel-plugin-proposal-function-sent, babel-plugin-proposal-json-strings, babel-plugin-proposal-object-rest-spread, babel-plugin-proposal-optional-chaining, babel-plugin-proposal-partial-application, babel-plugin-proposal-pipeline-operator, babel-plugin-proposal-private-property-in-object, babel-plugin-proposal-record-and-tuple, babel-plugin-syntax-typescript, babel-plugin-transform-block-scoped-functions, babel-plugin-transform-block-scoping, babel-plugin-transform-classes, babel-plugin-transform-computed-properties, babel-plugin-transform-destructuring, babel-plugin-transform-duplicate-keys, babel-plugin-transform-exponentiation-operator, babel-plugin-transform-flow-comments, babel-plugin-transform-flow-strip-types, babel-plugin-transform-for-of, babel-plugin-transform-function-name, babel-plugin-transform-modules-amd, babel-plugin-transform-modules-commonjs, babel-plugin-transform-modules-systemjs, babel-plugin-transform-modules-umd, babel-plugin-transform-object-super, babel-plugin-transform-parameters, babel-plugin-transform-property-mutators, babel-plugin-transform-proto-to-assign, babel-plugin-transform-react-constant-elements, babel-plugin-transform-react-display-name, babel-plugin-transform-react-inline-elements, babel-plugin-transform-react-jsx-compat, babel-plugin-transform-react-jsx-source, babel-plugin-transform-react-jsx, babel-plugin-transform-runtime, babel-plugin-transform-typescript, babel-plugin-transform-unicode-escapes, babel-preset-env, babel-preset-typescript, babel-standalone, babel-template, babel-traverse, babel-types
- #14601 enable noImplicitAny (@JLHwung)
babel-core, babel-helper-transform-fixture-test-runner, babel-plugin-transform-destructuring
- #14659 Run Babel asynchronously in fixtures (@nicolo-ribaudo)

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