# Upstream and issue review

Base: [feross/is-buffer](https://github.com/feross/is-buffer), npm `is-buffer@2.0.5`, commit `ec4bf3415108e8971375e6717ad63dde752faebf`. Full Git history and MIT license are retained. Last npm release: 2020-11-03. This indicates release inactivity, not proof that the upstream is abandoned.

Reviewed the 2026-09-28 collection of 100 most recently updated open and 30 closed issue/PR entries, with PRs excluded: one open issue and three closed issues were available. This is bounded issue triage, not exhaustive historical review.

- [#45](https://github.com/feross/is-buffer/issues/45): module has no initialization side effects. Added `sideEffects: false`; CommonJS remains supported and no ESM conversion is required for this metadata.
- Closed #28 and #20: old development tool update failures. Replaced wildcard/obsolete browser service tooling with pinned Tape and dependency-free browser-context tests; original Tape cases still run.
- Closed #13: engine changes break compatibility. Retained `node >=4` and the unchanged ES5 runtime source.

No confirmed runtime defect was identified in this review. Runtime source remains byte-for-byte identical to the selected upstream commit. Tests cover native Buffers, typed arrays, DataViews, cross-context inputs, and executing the module without a global Buffer. The browser-context check is a VM test, not a claim of a full browser matrix.