[Snyk] Security upgrade eslint from 8.57.0 to 9.0.0

[qbey]

Snyk has created this PR to fix 1 vulnerabilities in the yarn dependencies of this project.

Snyk changed the following file(s):

• packages/eslint-config-custom/package.json

Note for zero-installs users

If you are using the Yarn feature zero-installs that was introduced in Yarn V2, note that this PR does not update the .yarn/cache/ directory meaning this code cannot be pulled and immediately developed on as one would expect for a zero-install project - you will need to run yarn to update the contents of the ./yarn/cache directory.
If you are not using zero-install you can ignore this as your flow should likely be unchanged.

⚠️ Warning

Failed to update the yarn.lock, please update manually before merging.

Vulnerabilities that will be fixed with an upgrade:

	Issue	Score
	Inefficient Algorithmic Complexity SNYK-JS-JSYAML-17900054	710

Breaking Change Risk

Notice: This assessment is enhanced by AI.

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[qbey]

This is a major version upgrade to ESLint v9, which introduces significant and mandatory breaking changes. The most critical change is the move to a new default configuration file, eslint.config.js (known as "flat config"), which deprecates the traditional .eslintrc format. All projects must migrate their configuration to this new system.

Key Breaking Changes:

• New Configuration System: The eslint.config.js file is now the default. The old .eslintrc configuration format is deprecated and will require setting an environment variable (ESLINT_USE_FLAT_CONFIG=false) to continue using it temporarily. [1, 2, 3]
• Node.js Version Support: Support for Node.js versions below 18.18.0 and all of v19.x has been dropped. [1, 7]
• Removed Rules and Formatters: The valid-jsdoc and require-jsdoc rules have been removed. [1, 2] Additionally, several formatters (like checkstyle, compact, junit, tap) have been removed, with only stylish, html, json, and json-with-meta remaining. [2]
• CLI Behavior Change: The --quiet flag now skips executing rules set to "warn", which can change the output and performance of your linting process. [1, 2]

Recommendation: This upgrade requires a manual migration of your ESLint configuration from the .eslintrc format to the new eslint.config.js flat config format. You will also need to verify that all your ESLint plugins are compatible with v9 and the new configuration system. Review the official migration guide before upgrading.

Source: ESLint v9 Migration Guide

Notice 🤖: This content was augmented using artificial intelligence. AI-generated content may contain errors and should be reviewed for accuracy before use.