immer

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

Your version

9.0.0

major19 Mar 2021Where it was published

9.0.21 is the newest release of 9.x.

In short

2 breaking1 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.

Security

2 advisories affect 9.0.0; 9.0.6 fixes them

Critical
Prototype Pollution in immerGHSA-33f9-j839-rf8h · 2 Sep 2021
Fixed in 9.0.6
High
Prototype Pollution in immerGHSA-c36v-fmgq-m8hx · 7 Sep 2021
Fixed in 9.0.6

Release note

feature

Improved typescript types (2c2f30e), closes #720

Breaking changes

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.