test(deps): reconfigure for ESLint v9

[MikeMcC399]

• closes Migrate away from deprecated eslint-config-react-app #1576
• closes Migrate to ESLint 9.x #1616

Situation

ESLint in this repo does not trigger from yarn lint and if it is run manually, it produces many linting errors. It is also based on outdated, unsupported linting components. In summary, it is in a non-working state and so it is neither useful for contributors, nor as an example of how to configure ESLint for Cypress using supported components.

In detail:

• eslint@^8.44.0, configured in package.json, reached end-of-life on Oct 5, 2024. The supported current release line is ESLint 9.x.

• The package.json script definition lint does not lint any files with ESLint 8.x since none are specified

cypress-realworld-app/package.json

Line 158 in a7de449

"lint": "eslint && prettier --check \"**/**.{ts,js,tsx}\" \"*.{json,md,yml}\"",

• The shareable configuration eslint-config-react-app is part of the deprecated CRA repo and which requires peerDependencies "eslint": "^8.0.0" (now unsupported)

Change

Dependencies

• Update from unsupported eslint@8.57.1 to eslint@9.30.1
• Update from eslint-plugin-cypress@3.5.0 to eslint-plugin-cypress@5.1.0
• Add typescript-eslint@8.35.1
• Add @typescript-eslint/parser@8.35.1
• Remove eslint-config-prettier@8.10.0
• Remove eslint-plugin-prettier@5.2.1
• Remove deprecated eslint-config-react-app@7.0.1

Configuration

• Remove ESLint configuration from package.json
• Add new ESLint v9 configuration to eslint.config.mjs
• Note that eslint-plugin-prettier is removed, as prettier no longer recommends it on their Integrating with Linters page

Code changes

Remove disable of rules:

• react-hooks/*
• import/first

Verification

Ubuntu 24.04.2 LTS, Node.js 22.15.0 LTS, Yarn 1.22.22

git clean -xfd
yarn
yarn run prettier
yarn eslint --report-unused-disable-directives-severity 'off'

Confirm that no linting issues are reported.

When running

yarn lint

"Unused eslint-disable directive" may be reported as a warning.

TO-DOs

The following rules are disabled, since they produce errors against the current code. These can be addressed individually by reviewing the rule violations and either leaving the rule globally disabled, modifying code which provokes an error or disabling individual application of any particular rule:

      'no-empty': 'off',
      'no-prototype-builtins': 'off',
      'no-undef': 'off',
      'no-unused-vars': 'off',
      'prefer-const': 'off',
      '@typescript-eslint/ban-ts-comment': 'off',
      '@typescript-eslint/no-empty-object-type': 'off',
      '@typescript-eslint/no-explicit-any': 'off',
      '@typescript-eslint/no-non-null-asserted-optional-chain': 'off',
      '@typescript-eslint/no-unsafe-function-type': 'off',
      '@typescript-eslint/no-unused-expressions': 'off',
      '@typescript-eslint/no-wrapper-object-types': 'off',
      '@typescript-eslint/no-unused-vars': 'off',
      '@typescript-eslint/no-require-imports': 'off',
      '@typescript-eslint/triple-slash-reference': 'off',

[cypress-app-bot]

• Create a Draft Pull Request if your PR is not ready for review. Mark the PR as Ready for Review when you're ready for a Cypress team member to review the PR.

[MikeMcC399]

Refreshed ESLint dependencies and rebased

[MikeMcC399]

@jennifer-shehane / @AtofStryker

I'm requesting review for this PR that I submitted last month. It's not urgent, however I would appreciate it being looked at sometime soon.

[AtofStryker]

forked and ran locally and runs as expected. Thank you for updating this @MikeMcC399!