feat: add turbopack support for Next.js v16#43
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Next.js v16 defaults to Turbopack. The plugin previously hardcoded webpack for both build and serve, disabling turbopack entirely. - Add `webpack` boolean plugin option (defaults to false) so users can opt into webpack when needed, mirroring the `next build --webpack` CLI flag - Update `withHarper()` to include a `turbopack` config key, preventing Next.js v16 from erroring when it sees a webpack config without one - Add `next-16-webpack` fixture and integration test to cover both bundler paths Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
kriszyp
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May 6, 2026
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* feat: add turbopack support for Next.js v15 and refactor bundler option Replace the `webpack: boolean` plugin option with a `bundler` option that accepts "webpack" or "turbopack". The default is version-aware: - v16: turbopack (matches Next.js v16 default) - v15: webpack (matches Next.js v15 default) - v14: webpack (no turbopack support) Users can now explicitly set `bundler: turbopack` for v15 to opt in, or `bundler: webpack` for v16 to opt out. - Add `next-15-turbopack` fixture and integration test - Update `next-16-webpack` fixture to use `bundler: webpack` Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat: add v14 turbopack guard and validate all versions (#45) Next.js v14 does not support turbopack via the createServer or nextBuild APIs. Log an error and fall back to webpack if a user sets `bundler: turbopack` with a v14 application. Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
cb1kenobi
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May 6, 2026
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This works like a champ! Nice work!
[http/1] [debug]: Building Next.js application at /Users/chris/project
▲ Next.js 16.2.4 (Turbopack)
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Summary
webpackboolean plugin option (defaults tofalse) so v16 uses turbopack by default, matching the standard Next.js developer experience. Users can setwebpack: trueto opt back into webpack, mirroring thenext build --webpackCLI flag.withHarper()to include aturbopackconfig key in the returned Next.js config. Without this, Next.js v16 errors when it detects awebpackconfig function (added bywithHarper) with no correspondingturbopackconfig.webpackoption is ignored for those versions.Test plan
npm run build— TypeScript compiles cleannext-16.pw.ts— turbopack path (default): 3/3 passednext-16-webpack.pw.ts— webpack path (webpack: true): 3/3 passed🤖 Generated with Claude Code
Now incorporates changes from #44 and #45 too for v14 and v15 support.