[retyui]

Summary

fetch.js and src/* only declare and export fetch, Headers, Request and Response. They don't touch globals; installing them as globals is left to the consumer, for example polyfillGlobal('fetch', …). The only top-level statements besides declarations assign Response.error and Response.redirect on the package's own class.

"sideEffects": false

This lets bundlers drop the modules an app doesn't use, such as ArrayBufferResponse or BlobResponse.

Test plan

• Checked every top-level statement in the published 3.0.0 fetch.js and src/.