Upgrade ESLint to v10.4.0 with flat config

[zinduolis]

Pull Request

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Category

Core Functionality, CI

Feature/Issue Description

Q: Please give a brief summary of your feature/fix

A: Upgrades ESLint from v7.32.0 to v10.4.0 and migrates the configuration from the legacy .eslintrc.json format to the new flat config (eslint.config.js). Also pins all devDependency versions exactly and adds .npmrc with min-release-age=3 for supply-chain safety.

Q: Give a technical rundown of what you have changed (if applicable)

A:

• Deleted .eslintrc.json — ESLint 10 removed support for the legacy config format entirely.
• Created eslint.config.js — Equivalent flat config with the same rules, globals, and ignore patterns. Uses @eslint/js for recommended rules and the globals package for browser globals (replaces "env": { "browser": true }).
• Updated package.json:
  • eslint: 7.32.0 → 10.4.0
  • Added @eslint/js: 10.0.1
  • Added globals: 17.6.0
  • All versions pinned exactly (no ^ or ~)
  • Lint scripts updated to target . (flat config handles ignores internally)
• Created .npmrc — Sets min-release-age=3 to refuse packages published less than 3 days ago (requires npm 11.10+, currently active in CI on Node 24).
• Updated .github/workflows/eslint.yml — Changed npx eslint "**/*.js" to npx eslint . in the report-only job to align with flat config file resolution.
• Regenerated package-lock.json with the new dependency tree.

Test Cases

Q: Describe your test cases, what you have covered and if there are any use cases that still need addressing.

A: Ran both CI jobs locally using act:

• lint-all-files — ESLint 10 ran successfully against the full codebase. 5654 pre-existing errors reported (same issues ESLint 7 would flag). Job completed with success (non-blocking, continue-on-error: true).
• lint-changed-files — No JS files in the test diff, correctly skipped linting. Job completed with success.

No new lint errors were introduced by this change. All errors are pre-existing codebase issues.

Wiki Page

N/A — no new user-facing features. The linting infrastructure is transparent to contributors; npm run lint continues to work as before.