[jrandolf]

Motivation

Provide the v4 migration path for the field rename requested in #1229.

Approach

Add cause as a non-enumerable, read-only alias of error, and deprecate error. Keep cause optional in Result<T> so existing object literals remain valid. Error wrapping and unboxing stay compatible with v4.

Coverage includes alias identity, changes through error, legacy results, and allSettled(). Local Deno tests, lint, formatting, type checks, and the Node test build pass.

Fix CI by naming the benchmark package to prevent npm's audit crash.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/effection@1264

commit: 1e7b52e

[codspeed]

Merging this PR will not alter performance

✅ 6 untouched benchmarks

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_{Comparing jrandolf:jrandolf/result-reason-v4 (1e7b52e) with v4 (c623418)}