The @babel/plugin-transform-duplicate-keys npm package is designed to help developers manage object literals in JavaScript that have duplicate keys. When using this plugin, Babel will transform object literals containing duplicate keys by ensuring that the last key-value pair is the one that is ultimately defined, following the standard JavaScript behavior. This can be particularly useful in scenarios where code is being generated or transformed and duplicate keys may be introduced unintentionally.

What are @babel/plugin-transform-duplicate-keys's main functionalities?

Transforming Duplicate Keys in Object Literals

This feature allows the transformation of object literals with duplicate keys in JavaScript code. The plugin ensures that if an object literal contains duplicate keys, only the last occurrence of the key is kept, and previous ones are ignored. This aligns with the standard JavaScript behavior where the last property assignment overrides earlier assignments with the same key.

{"type": "object", "properties": {"duplicateKey": {"type": "string"}, "duplicateKey": {"type": "number"}}}

Other packages similar to @babel/plugin-transform-duplicate-keys

Changelog

Source

v7.18.9 (2022-07-18)

:bug: Bug Fix

babel-plugin-transform-modules-systemjs, babel-types
- #14763 fix: allow exporting TSDeclareFunction as default (@zxbodya)
babel-generator
- #14758 fix: returnType with comments generates incorrect code (@liuxingbaoyu)

:nail_care: Polish

babel-cli
- #14748 Print a message when the watcher of babel-cli is ready. (@liuxingbaoyu)

:house: Internal

babel-core, babel-helper-remap-async-to-generator, babel-helpers, babel-parser, babel-plugin-transform-block-scoping, babel-preset-env
- #13414 Prepare for compiling Babel to native ESM (@nicolo-ribaudo)
babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-helper-remap-async-to-generator, babel-helper-replace-supers, babel-helper-wrap-function, babel-helpers, babel-plugin-bugfix-v8-spread-parameters-in-optional-chaining, babel-plugin-proposal-decorators, babel-plugin-proposal-object-rest-spread, babel-plugin-proposal-optional-chaining, babel-plugin-transform-block-scoping, babel-plugin-transform-classes, babel-traverse, babel-types
- #14739 Provide better parentPath typings (@JLHwung)

:running_woman: Performance

babel-generator
- #14701 perf: Improve generator perf (@liuxingbaoyu)

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