Config clone before validating kills Object data (7.3.0)

• ESLint Version: 7.3.0

The latest update breaks eslint-plugin-import and I believe some other eslint plugins due to configuration cloning by JSON.parse(JSON.stringify(Object)) related PR: https://github.com/eslint/eslint/pull/13034

Any plugin that use any global property like “Infinity” wont work properly.

JSON.parse(JSON.stringify(Infinity)) => null

Configuration example https://github.com/airbnb/javascript/blob/master/packages/eslint-config-airbnb-base/rules/imports.js#L236

[boeric]

Eslint is an awesome tool to ensure code style consistency, especially when paired with airbnb’s stricter rules. The eslint-config-airbnb-base, with some 3 million weekly downloads, now breaks with 7.3.0 as pointed out. A humble suggestion for the future is to integrate tests that represents how eslint is used by the most popular repos in its ecosystem (of which eslint-config-airbnb-base is one) and not break compatibility until the next major rev

[ljharb]

Given the rarity of users using print-config or cache, and considering this has been in the airbnb config for two years, it seems likely that there’s a significant amount of the ecosystem that is unaware that rule schemas must be JSON-serializable values.

I implore you to reconsider and delay this restriction until the next semver-major, and consider this a missed opportunity from the v7.0.0 release.