fix(lint): native flat config for eslint-config-next 16, drop next lint - #85
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ESLint has not been runnable on main since the Next 16 bump:
- `next lint` was removed in Next 16, so `pnpm lint:eslint` fails immediately
- eslint-config-next 16 ships native flat configs, and FlatCompat cannot
convert them ("Converting circular structure to JSON")
Changes:
- eslint.config.mjs imports eslint-config-next/core-web-vitals and
eslint-config-next/typescript directly and uses typescript-eslint's
recommendedTypeChecked + stylisticTypeChecked (same presets as before)
- type-aware rules are disabled for files tsconfig.json excludes (scripts/,
tests/, src/workers/, (ai), (demo)/examples, *.config.ts), which previously
produced "parserOptions.project" parse errors
- lint:eslint / lint:fix:eslint now run `eslint .`
- typescript-eslint 8.70.0 added as a direct devDependency; @eslint/eslintrc
removed (no longer used)
`pnpm lint:eslint` now runs to completion: 75 errors, 124 warnings, all
pre-existing code findings (prefer-nullish-coalescing, no-unnecessary-type-
assertion, no-explicit-any, ...). Fixing those is separate work.
This is groundwork for ESLint 10, which is still blocked: eslint-config-next
depends on eslint-plugin-react 7.37.5, whose rules call context.getFilename(),
removed in ESLint 10 ("react/display-name: contextOrFilename.getFilename is not
a function"). No eslint-plugin-react release supports ESLint 10 yet.
Claude-Session: https://claude.ai/code/session_01KLWmWU1KLE2diUH14ryqv1
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One sentence
Makes ESLint runnable again after the Next 16 bump by importing eslint-config-next 16 flat configs directly and replacing the removed
next lintcommand; not a dependency bump, so left open for review.Why
Found while attempting the ESLint 10 major for LAC-3869. On
main,pnpm lint:eslintrunsnext lint, which Next 16 removed (https://github.com/vercel/next.js/blob/canary/docs/01-app/02-guides/upgrading/version-16.mdx). Runningeslintdirectly also crashes:eslint-config-next16 exports native flat-config arrays andFlatCompat.extends("next/core-web-vitals")fails withConverting circular structure to JSON.Changes
eslint.config.mjs: importseslint-config-next/core-web-vitalsandeslint-config-next/typescriptdirectly (the way the Next 16 docs show) and appliestypescript-eslintrecommendedTypeChecked+stylisticTypeChecked, the same presets FlatCompat used to pull in. Rule overrides and ignores are unchanged.tseslint.configs.disableTypeChecked) for the pathstsconfig.jsonexcludes (scripts/,tests/,src/workers/,(ai),(demo)/examples,*.config.ts,*.config.*.ts); those files produced"parserOptions.project" has been providedparse errors before.lint:eslint->eslint .,lint:fix:eslint->eslint . --fix.Result
pnpm lint:eslintnow completes: 75 errors and 124 warnings, all pre-existing code findings (24prefer-nullish-coalescing, 10no-unnecessary-type-assertion, 8no-explicit-any, 4require-await, 4no-require-imports, 2react/no-unescaped-entities, 2react/display-name, ...). Fixing them is separate work, sopnpm lintstill exits non-zero, but it now says why instead of crashing.ESLint 10 is still blocked
With this config and
eslint@10.10.0, linting any component crashes inreact/display-name:contextOrFilename.getFilename is not a function.eslint-config-next@16.3.5depends oneslint-plugin-react@^7.37.0; 7.37.5 (April 2025) is the latest release and still usescontext.getFilename(), which ESLint 10 removed. Its peer range iseslint ^3 ... ^9.7;eslint-plugin-importandeslint-plugin-jsx-a11yalso cap at^9. Untileslint-plugin-reactships ESLint 10 support andeslint-config-nextpicks it up, ESLint 10 cannot be adopted here. Source: https://github.com/eslint/eslint/blob/main/docs/src/use/migrate-to-10.0.0.mdVerification
pnpm typecheckcleanpnpm test: 4 files, 16 tests greenpnpm exec vitest run --config vitest.config.node.ts: 3 files, 21 tests greenpnpm buildpassesnext startsmoke:/200,/changelog200,/changelog/nope-xyz404,/faq200,/nope-404404Installed with
--ignore-scripts(isolated-vm postinstall fails under Node 26 locally; matches how Vercel builds).https://claude.ai/code/session_01KLWmWU1KLE2diUH14ryqv1