What?

Capture setImmediate[promisify.custom] at module initialization instead of lazily accessing it when needed.

    RangeError: Maximum call stack size exceeded

      at patchedSetImmediatePromise (node_modules/.pnpm/next@16.1.1_@babel+core@7.28.5_react-dom@19.2.3_react@19.2.3__react@19.2.3/node_modules/next/src/server/node-environment-extensions/fast-set-immediate.external.ts:626:27)
      at originalPromisify (node_modules/.pnpm/next@16.1.1_@babel+core@7.28.5_react-dom@19.2.3_react@19.2.3__react@19.2.3/node_modules/next/src/server/node-environment-extensions/fast-set-immediate.external.ts:627:12)

This was discovered upgrading from 16.0.10 to 16.1.0

Why?

When util.promisify(setImmediate) is called and currentExecution === null, the code was accessing originalSetImmediate[promisify.custom] at call time. However, promisify.custom can get lost or return undefined after the module patches setImmediate, causing promisify(setImmediate) to fail. Specifically, when used with jest.

Reproduction: https://github.com/jgeschwendt/nextjs-setimmediate-promisify-repro

• Failing: https://github.com/jgeschwendt/nextjs-setimmediate-promisify-repro/actions/runs/20864170776
• Passing (with fix): https://github.com/jgeschwendt/nextjs-setimmediate-promisify-repro/actions/runs/20864380068
  • Fix setImmediate promisify infinite recursion via pnpm patch jgeschwendt/nextjs-setimmediate-promisify-repro#1

How?

Move the capture of originalSetImmediate[promisify.custom] to module initialization time (alongside originalSetImmediate, originalClearImmediate, and originalNextTick), ensuring the original promisified implementation is preserved before any patching occurs.