chore: migrate to ESLint flat config and pnpm

[ricokahler]

Motivation

This PR updates the project's linting setup to use ESLint's modern "Flat Config" system (eslint.config.mjs) and standardizes on pnpm as the package manager. This provides a more explicit and potentially more maintainable configuration structure, aligns with the direction of the ESLint ecosystem, and ensures consistent dependency management.

This is the foundational change in a series of PRs aimed at refactoring and improving the codebase.

Key Changes:

1. ESLint Flat Config Migration:

   • Removed the legacy .eslintrc.js and .eslintignore files.
   • Introduced a new eslint.config.mjs file using tseslint.config().
   • Configured ESLint using recommended presets (eslint.configs.recommended, eslintPluginPrettierRecommended, tseslint.configs.recommended).
   • Defined baseline rules directly within the config (e.g., @typescript-eslint/no-explicit-any: 'off', no-console: 'error', basic unused vars handling).
   • Added an ignores array in the config to specify files/directories to exclude from linting (replacing .eslintignore).

2. Switch to pnpm:

   • Replaced package-lock.json with pnpm-lock.yaml.
   • Updated the GitHub Actions workflow (.github/workflows/test.yml) to use pnpm for installing dependencies and running scripts (pnpm install, pnpm run lint, pnpm test, pnpm run build).
   • Added pnpm/action-setup to the CI workflow for efficient pnpm caching.

3. Dependency Cleanup:

   • Removed eslint-config-sanity and eslint-plugin-simple-import-sort as linting configuration is now handled directly or via standard recommended sets. (More specific import linting will be added in a subsequent PR).

4. Script Updates:

   • Added a lint script (eslint .) to package.json.
   • Updated CI workflow to run the new lint script instead of the previous prettify-check.

5. .gitignore Update:

   • Added .tap to ignore tap test snapshot/output directories.

Impact

• Standardizes the project on pnpm for dependency management.
• Modernizes the ESLint configuration to the Flat Config system.
• Provides a clearer base for future linting rule additions.
• Removes some now-unused dev dependencies.
• Requires developers working on the project to use pnpm.
• This change primarily affects the development tooling and setup; it should have no impact on the runtime behavior or the published package for consumers.

[ricokahler]

• #281
• #280
• #279 👈 (View in Graphite)
• v2

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[socket-security[bot]]

New, updated, and removed dependencies detected. Learn more about Socket for GitHub ↗︎

Package	New capabilities	Transitives	Size	Publisher
npm/@microsoft/[email protected] ➜ 7.52.2	Transitive: environment, eval, filesystem, shell, unsafe	+44	12.8 MB	odspnpm
npm/@sanity/[email protected] ➜ 1.0.5	None	0	0 B
npm/@sanity/[email protected] ➜ 7.2.2	Transitive: eval, filesystem, network, shell, unsafe	+217	33.4 MB	sanity-io
npm/@typescript-eslint/[email protected] ➜ 8.29.0	Transitive: environment, filesystem	+35	3.12 MB
npm/@typescript-eslint/[email protected] ➜ 8.29.0	Transitive: environment, filesystem	+27	1.36 MB
npm/[email protected] ➜ 4.4.0	None	+1	49.5 kB	qix
npm/[email protected] ➜ 10.1.1	None	0	58.4 kB	jounqin
npm/[email protected]	Transitive: filesystem	+8	358 kB	alexgorbatchev, bradzacher, jounqin
npm/[email protected] ➜ 5.2.5	None	+5	273 kB	jounqin
npm/[email protected] ➜ 9.23.0	Transitive: eval, shell, unsafe	+83	10.2 MB	eslintbot
npm/[email protected] ➜ 3.5.3	None	0	0 B
npm/[email protected] ➜ 24.2.3	Transitive: eval, filesystem, shell, unsafe	+271	36 MB	semantic-release-bot
npm/[email protected] ➜ 7.7.1	None	0	96.7 kB	npm-cli-ops
npm/[email protected] ➜ 21.1.0	None	+281	56.2 MB	isaacs
npm/[email protected] ➜ 4.19.3	Transitive: environment, filesystem, network, shell	+3	691 kB	hirokiosame
npm/[email protected]	Transitive: environment, filesystem	+30	1.85 MB	jameshenry
npm/[email protected], 5.7.2 ➜ 5.8.2	None	0	22.9 MB	typescript-bot

🚮 Removed packages: npm/@types/[email protected], npm/[email protected], npm/[email protected]

View full report↗︎

[socket-security[bot]]

🚨 Potential security issues detected. Learn more about Socket for GitHub ↗︎

To accept the risk, merge this PR and you will not be notified again.

Alert	Package	Note	Source	CI
License Policy Violation	npm/[email protected]	License: unrecognized license (package/ThirdPartyNoticeText.txt)	package.json pnpm-lock.yaml	⚠︎
License Policy Violation	npm/[email protected]	License: unrecognized license (package/ThirdPartyNoticeText.txt)	package.json pnpm-lock.yaml	⚠︎
License Policy Violation	npm/[email protected]	License: unrecognized license (package/LICENSE.md)	package.json pnpm-lock.yaml	⚠︎

View full report↗︎

Next steps

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Find a package that does not violate your license policy or adjust your policy to allow this package's license.

Take a deeper look at the dependency

Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support [AT] socket [DOT] dev.

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