is-extendable is a JavaScript utility that returns whether a value is one of the types that can be extended (array, plain object, or function). It is useful for safely deciding if a value should support key-based extension.
Project status
- This GitHub source appears largely dormant, with the last upstream push on 2021-08-20, and no updates since 2017 (latest shown version 1.0.1 on 2017-09-11), so it does not look actively maintained as of 2026-09-10.
- The update cadence is long gaps, with releases in 2015, 2017, and then no further activity shown after 2021’s upstream push, indicating no current cadence to track.
AI summary generated
Recent updates
1.0.1
Release 1.0.1 does not include any publisher-provided release notes. The code diff shows this version primarily adds TypeScript type definitions and updates package metadata to ship them.
1.0.0
No publisher release notes were provided for version 1.0.0 (the <release_notes> section is empty). The code diff shows a major behavioral change to is-extendable, plus various repo/tooling updates (linting, CI matrix, and documentation generation).
0.1.1
Release 0.1.1 was published, but no release notes were provided by the publisher. There is no documented information about new features, bug fixes, security updates, or breaking changes in the supplied data.
0.1.0
Release 0.1.0 was published on 2015-06-29, but no release notes were provided by the publisher. As a result, there is no documented information about new features, bug fixes, breaking changes, security updates, or migration steps for this version.