@babel/plugin-transform-duplicate-keys removes or merges duplicate keys in object literals. During compilation, it identifies instances where the same key is defined multiple times within an object. It either removes older definitions, keeping the last one, or merges the values if the duplicate keys were a result of spread operations with overlapping properties. This plugin helps ensure consistent behavior across JavaScript engines and can remove potential runtime errors or unexpected object states caused by duplicate keys.
The @babel/plugin-transform-duplicate-keys package has seen sporadic releases since August 2018. Releases were most frequent in 2020 and 2021, with occasional releases in other years. 2025 has only had one release in April. There have been no releases in the last four months.
@babel/plugin-transform-duplicate-keys downloads peaked in June 2025 at 130 million. Downloads remained high throughout early 2025, generally exceeding 100 million. September 2025 downloads are significantly lower, at roughly 40 million, but this likely reflects incomplete data for the current month.
