immer

11.2.9 · 22 Oct 2026MIT89.4M / weekRepository Homepage npm Atom feed

Upgrading immer From 8.0.4 to 9.0.0

Same major only

1 release in betweenevery note read

Other targets from 8.0.4Clears its 2 advisories9.0.6 Latest11.2.9

8.0.4yours
9.0.0target

2
changes to make: 0
advisories fixed: 1
new: 0
fixes

Before you upgrade

Tick each one off as you go

It is no longer allowed to return nothing from a recipe if the target state doesn't accept undefined.
breaking9.0.0
It is no longer allowed to return arbitrary things from a recipe. Recipes should either return nothing, or something that is assignable to the original state type. This will catch mistakes with accidental returns earlier.
breaking9.0.0

Security

2 advisories still affect 9.0.0

Prototype Pollution in immercritical · GHSA-33f9-j839-rf8h
Prototype Pollution in immerhigh · GHSA-c36v-fmgq-m8hx

Upgrading to 9.0.6 clears them.

Release by release

9.0.0
Migration needed19 Mar 20211 new
- breaking
  It is no longer allowed to return nothing from a recipe if the target state doesn't accept undefined.
- breaking
  It is no longer allowed to return arbitrary things from a recipe. Recipes should either return nothing, or something that is assignable to the original state type. This will catch mistakes with accidental returns earlier.
- new
  Improved typescript types (2c2f30e), closes #720

Upgrade to 9.0.0

npm install immer@9.0.0

What 9.0.0 needs

Reading 9.0.0's manifest…

Check against your package.json

Which of your other dependencies stand in the way of 9.0.0. Read once, not stored.

After upgrading

Run the type checker, the linter and the tests.
Build, and look for new deprecation warnings.
Update peer dependencies the new version asks for.
2 advisories still affect 9.0.0.