Description

• closes toEqual/toStrictEqual does not check custom Error properties #5244
• closes The "cause" property of Error is ignored when matching #5697

NodeJs PR for a reference

• assert: add deep equal check for more Error type nodejs/node#51805

todo

• error equality
• error formatting
• asymmetrically show cause diff
• handle cyclic object
  • it can fail due to chai's error message generation Maximum call stack size exceeded when assertion fails with cyclic references of Error.cause  chaijs/chai#1645 Fixed!
• should we update toThrowError(new Error(...)) usage too? (I think so)
• should we break snapshot too? (for now, new error formatter is applied only when diffing and this looks fine)
• docs

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. If the feature is substantial or introduces breaking changes without a discussion, PR might be closed.
• Ideally, include a test that fails without this PR but passes with it.
• Please, don't make changes to pnpm-lock.yaml unless you introduce a new test example.

Tests

• Run the tests with pnpm test:ci.

Documentation

• If you introduce new functionality, document it. You can run documentation with pnpm run docs command.

Changesets

• Changes in changelog are generated from PR name. Please, make sure that it explains your changes in an understandable manner. Please, prefix changeset messages with feat:, fix:, perf:, docs:, or chore:.