Major maintenance update: App Router support, dependency bumps, website overhaul #271

The project has been dormant since mid-2023. This issue tracks the full maintenance update to make create-next-stack current and relevant again.

Key decisions

• Support both App Router (default) and Pages Router via --router flag
• Update all plugin dependencies to latest major versions
• Migrate website from Chakra UI to Mantine, Pages Router to App Router

Phase 0: Build tooling & infrastructure

• TypeScript 4.9 -> 5.x (superseded by Phase 9: now ^6)
• Turbo v1 -> v2 (pipeline -> tasks)
• Prettier v2 -> v3
• pnpm v8 -> v10
• Husky v8 -> v9
• oclif v2 -> v4
• Node engines >=18 -> >=20
• GitHub Actions versions (setup-node@v4, checkout@v4, pnpm/action-setup@v4) (superseded by Phase 9: @v6 / @v6 / @v5)

Phase 1: Slot system refactoring + router flag

• Add --router flag (app/pages, default app)
• Refactor Plugin type: rename slots.app -> slots.pagesApp, add slots.appLayout for App Router
• App Router providers.tsx pattern (separate 'use client' wrapper component)
• New generators: app/layout.tsx, app/providers.tsx, app/page.tsx
• Conditional file generation based on router flag
• Update Next.js plugin: create-next-app 13.2.3 -> 15.x, update CNA flags

Phase 2: Plugin updates

Simple bumps

• framer-motion -> motion ^12 (package renamed, imports from motion/react)
• react-icons ^4 -> ^5
• prisma ^4 -> ^6 (v7 too breaking; see Finish Prisma support #270) (Phase 9 re-evaluated v7 — still too breaking; left at ^6)
• vercel ^30 -> ^50, netlify ^15 -> ^24 (superseded by Phase 9: vercel ^51, netlify ^25)
• github-actions template update (checkout@v4, setup-node@v4, pnpm/action-setup@v4) (superseded by Phase 9)
• react-query ^4 -> ^5 + App Router provider slots
• sass, next-plausible, react-hook-form, formik version checks + App Router slots where needed (next-plausible slipped — caught and bumped to ^4 in Phase 9)

Breaking changes

• Tailwind CSS v3 -> v4 (CSS-based config via @import "tailwindcss", drop tailwind.config.js/autoprefixer, use @tailwindcss/postcss)
• Chakra UI v2 -> v3 (still needs @emotion/react, drops @emotion/styled/framer-motion/@chakra-ui/icons, uses createSystem/defineConfig, needs next-themes)
• Mantine v6 -> v8 (dropped Emotion, uses PostCSS with postcss-preset-mantine, CSS imports, createTheme). Hybrid App Router approach: layout slots for CSS import/mantineHtmlProps/ColorSchemeScript, provider slots for MantineProvider (superseded by Phase 9: now ^9)
• Material UI v5 -> v7 + @mui/material-nextjs for App Router (AppRouterCacheProvider) (superseded by Phase 9: now ^9)
• Styled Components v5 -> v6 (built-in TS types, drop @types/styled-components, add App Router registry via useServerInsertedHTML)
• Emotion: add App Router provider slots (CacheProvider + useServerInsertedHTML), add README todo about CSS-in-JS Client Component requirement
• CSS Modules: App Router layout import (done in Phase 1)

Infrastructure

• Add postcssConfig slot to Plugin type (like nextConfig slots) for PostCSS plugin merging (Mantine + Tailwind coexistence)
• Migrate next.config.js -> next.config.ts generation

Formatting/hooks

• Prettier ^2 -> ^3, eslint-config-prettier ^8 -> ^10
• Drop mrm/mrm-task-lint-staged, use Husky v9 (npx husky init) + lint-staged ^16

Phase 3: Validation rules

• Remove "Mantine requires Emotion" constraint
• Keep "Chakra requires Emotion" (v3 still uses Emotion)
• Remove "Chakra requires Framer Motion" constraint
• Keep "Material UI requires Emotion"
• Update flag descriptions to match (Chakra, Mantine)

Phase 4: E2E tests

• Add --router=pages test variants (pages-router-emotion-all-flags, pages-router-tailwind-css-only)
• Add --prisma and --github-actions to all-flags tests
• Add Mantine-without-Emotion test (tailwind-css-with-mantine)
• Remove obsolete invalid-input cases (mantineWithoutEmotion, chakraWithoutFramerMotion)
• Update chakraWithoutEmotion test (remove --framer-motion from args)

Bugs found and fixed during E2E testing

• oclif v4 single-command CLI: commands config must use { strategy: "single", target: "..." } format instead of old string path + default key. Without this, flags like --debug were parsed as command names.
• CNA 15 Turbopack prompt: create-next-app@15 now prompts interactively for Turbopack. Added --turbopack flag to prevent hanging.
• LandingPageTemplate missing "use client": Template uses onLoad, localStorage, and window -- needs client directive for App Router.
• Emotion jsxImportSource breaks App Router: Setting jsxImportSource: "@emotion/react" globally in tsconfig makes Server Components import Emotion's JSX runtime, causing createContext is not a function. Fix: only set for Pages Router, use per-file pragma for App Router.
• Emotion cache.inserted type: EmotionCache.inserted is typed as Record<string, string | true | undefined> -- no any cast needed. Values of true indicate already-inserted styles that should be skipped.

CI fixes (PR #274)

• Vitest 4 CLI changes: --json lists test cases not files (use --filesOnly), --poolOptions.* removed (use --no-fileParallelism)
• ESM require.resolve(): Replace with import.meta.resolve() + fileURLToPath()
• Node type stripping: Add verbatimModuleSyntax: true, convert 53 files to import type
• Generated import extensions: Use extensionless imports (.ts/.tsx extensions fail across router configs)
• Generated template lint errors: Fix no-explicit-any in LandingPage utils
• pnpm frozen-lockfile in CI: Use explicit --no-frozen-lockfile flag (pnpm uses ci-info to detect CI)
• Duplicate ThemeProvider: Alias MUI's to MuiThemeProvider when Chakra+MUI coexist
• Plausible env var narrowing: Move null check from providerAfterImports to providerLogic for TS narrowing
• pnpm @types/react corruption: auto-install-peers rewrites @types/react to ^6.0.0; fix by adding explicit @types/react@^19 devDep
• Duplicate imports in generated code: Add prettier-plugin-organize-imports as tmpDependency to dedupe/sort imports during formatting
• Lock file format check failure: Generate .prettierignore (with prettier plugin) to exclude lock files; E2E creates temp ignore when prettier not selected
• Styled-components rules-of-hooks: Extract StyledComponentsRegistry component so early return doesn't make other plugins' hooks conditional

Phase 5: Website overhaul

• Migrate from Chakra UI to Mantine v8
• Migrate from Pages Router to App Router
• Add Router selector to form
• Update validation rules and command builder
• Bump Next.js 13 -> 15, React 18 -> 19

Phase 6: Next.js 16 / CNA 16 support

• Update create-next-app from v15 to v16, add --yes flag (skips React Compiler prompt)
• ESLint: .eslintrc.json -> eslint.config.mjs (flat config, ESLint v9)
• Lint script: next lint -> eslint
• Prettier ESLint integration: update for flat config compat (eslint-config-prettier)
• Update removeOfficialCNAContent for CNA 16 file structure
• Fix Prettier formatting in CLI package (35 files reformatted)
• Update E2E performFinalChecks for new lint command (already uses npm run lint)
• Update website to Next.js 16

Phase 7: Update internal tooling dependencies

Website

• ESLint ^9 -> ^10 Blocked: eslint-config-next@16 plugins don't support ESLint 10 yet
• @types/node ^22 -> ^25

CLI internal tooling

• ESLint ^8 -> ^10 + migrate .eslintrc to eslint.config.mjs (flat config)
• @typescript-eslint/* ^7 -> ^8 (replaced with unified typescript-eslint package)
• Jest ^29 -> ^30, @jest/globals ^29 -> ^30
• next (devDep) ^15 -> ^16
• @types/node ^20 -> ^25

Phase 8: Migrate CLI to ESM

• tsconfig.json: module: "nodenext", moduleResolution: "nodenext", rewriteRelativeImportExtensions: true, drop declaration: true
• package.json: add "type": "module"
• bin/run + bin/dev: convert require() to import()
• Replace __dirname usages with import.meta.dirname
• Add .ts extensions to all relative imports
• Bump chalk ^4 -> ^5 (ESM-only), execa ^5 -> ^9 (ESM-only)
• Replace endent with aldent (ESM-native), published aldent 0.0.7 with compiled JS output
• Replace Jest with Vitest (native ESM + .ts import support)
• Verify build, lint, unit tests, and CLI execution

Phase 9: Post-merge review follow-ups (2026-04-18)

Discovered during a post-merge review of #274. PR did what it said, but two bugs slipped through and several "update to latest" todos are now stale after time passed.

Bugs

• plugins/material-ui.ts:87: import path is @mui/material-nextjs/v15-appRouter but CNA is pinned to v16 — change to /v16-appRouter (breaks MUI + App Router on Next 16)
• plugins/plausible.ts:11: next-plausible still pinned ^3.0.0; v4 shipped. Missed during Phase 2a "version checks".

Version currency (missed or released since merge)

• TypeScript ^5 -> ^6
• MUI ^7 -> ^9 (both @mui/material and @mui/material-nextjs; resolves the v15→v16 import path above)
• Mantine ^8 -> ^9 (plugin + website)
• vercel CLI ^50 -> ^51 (^50.0.0 does NOT cover v51)
• netlify-cli ^24 -> ^25
• GH Actions bump (both .github/workflows/*.yml AND plugins/github-actions.ts template):
  • actions/checkout@v4 -> @v6
  • actions/setup-node@v4 -> @v6
  • pnpm/action-setup@v4 -> @v5
• Revisit Finish Prisma support #270: Prisma v7 is now released — re-evaluate the "too breaking" block. Still too breaking: v7 requires provider rename (prisma-client-js → prisma-client), mandatory output field, new prisma.config.ts, driver adapters (e.g. @prisma/adapter-better-sqlite3), import-path changes, removed middleware, disabled env auto-load. Needs a dedicated migration PR — left at ^6.