cloudflare/vinext

Build: `next.config.ts` with TS import aliases / `baseUrl` fails

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#1,512 opened on May 22, 2026

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Description

This issue was created by an agent analysing CI failures from the Next.js Deploy Suite (vinext main vs Next.js v16.2.6, 2026-05-22).

Problem

A next.config.ts that uses TS path aliases / baseUrl in CJS mode fails to build (Custom deploy script failed: undefined). Distinct from #1345 (__dirname redeclaration) — this is about TS path-alias resolution at config-load time.

next.config.ts with import aliases + baseUrl fails to build

Estimated Impact

~1 test failures across the deploy suite.

Affected Test Suites

  • test/e2e/app-dir/next-config-ts/import-alias-paths-with-baseurl/next-config-ts-import-alias-paths-with-baseurl-cjs.test.ts

Recommendation

  1. Reproduce first in vinext's own test suite. Add a next.config.ts that imports a path alias via tsconfig's paths. Confirm the build fails.

  2. Resolve TS aliases when loading next.config.ts. When loading the config in CJS mode, read tsconfig.json paths/baseUrl and pass them to the TS loader so the config file can use aliased imports.

Part of #1328.

Contributor guide

Research direction
Reproduce the build failure using the existing CJS config test suite. Then update the config loader to resolve TypeScript path aliases from tsconfig.json paths and baseUrl when loading next.config.ts.
Tech stack
typescriptnextjsvite
Domain
build system
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
TypeScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65