vuex/docs/en/strict.md

Strict Mode

To enable strict mode, simply pass in strict: true when creating the Vuex instance:

const vuex = new Vuex({
  // ...
  strict: true
})

In strict mode, whenever Vuex state is mutated outside of mutation handlers, an error will be thrown. This ensures that all state mutations can be explicitly tracked by debugging tools.

Development vs. Production

Do not enable strict mode when deploying for production! Strict mode runs a deep watch on the state tree for detecting inappropriate mutations - make sure to turn it off in production to avoid the performance cost.

Similar to middlewares, we can let the build tools handle that:

const vuex = new Vuex({
  // ...
  strict: process.env.NODE_ENV !== 'production'
})