Uncaught TypeError: Cannot set property 'itx' of undefined

[mbranicky]

Version

5.0.3

Browser and OS info

Chrome 73 / macOS 10.14.3

Steps to reproduce

On the Chrome, it throws an error "Uncaught TypeError: Cannot set property 'itx' of undefined" when I use "registerModule" to dynamically register a nested VUEX module.

Here is our code:

const url = 'static/itx/template-3.itx'
this.$store.registerModule(['designer', `editor${url}`], module)

The position of error code and stack is here:
https://www.dropbox.com/s/kqlahuin84820ay/stacktrace_1.png?dl=0
https://www.dropbox.com/s/howoq8zbrk9da56/stacktrace_2.png?dl=0

What is expected?

The 'object' should not be undefined.

What is actually happening?

Initially the 'object' is the parentState but after the 'while' loop it becomes obviously undefined, because property 'itx' is not a property of parentState.

[blu14x]

yep. same here

[mbranicky]

@znck Working re-producible example: https://3yn2988r01.codesandbox.io/

If you want to see the code: https://codesandbox.io/s/3yn2988r01?fontsize=14

[anisiewicz]

Problem is with module with state returned form function:

OK

this.$store.registerModule(['bar'], {
      namespaced: true,
      modules: {
        foo: {
          namespaced: true,
          state: {barfoo: 'x'},
          mutations: {
            save (state, v) {
              state.barfoo = v
            },
          }
        }
      },
      state: { bee: 'x'}        
    })
    this.$store.commit(`bar/foo/save`, 'new_content')

NOK:

this.$store.registerModule(['bar'], {
      namespaced: true,
      modules: {
        foo: {
          namespaced: true,
          state: {barfoo: 'x'},
          mutations: {
            save (state, v) {
              state.barfoo = v
            },
          }
        }
      },
      state () {
        return{ bee: 'x'}
      },                
    })
    this.$store.commit(`bar/foo/save`, 'new_content')

Result: state representation in devtools is missing modules.

When I'm trying to load state:

Uncaught TypeError: Cannot set property 'barfoo' of undefined
    at Store.save (App.vue?234e:62)
    at wrappedMutationHandler (vuex.esm.js?2f62:714)
    at mutation.handlers.forEach.handler (backend.js:12126)
    at Array.forEach (<anonymous>)
    at replayMutations (backend.js:12126)
    at Bridge.bridge.on.index (backend.js:12046)
    at Bridge.emit (backend.js:3205)
    at Bridge._emit (backend.js:3028)
    at messages.forEach.message (backend.js:2953)
    at Array.forEach (<anonymous>)

I thinik is realated to #922

Another case, when module has no state defined:

this.$store.registerModule(['bar'], {
      namespaced: true,
      modules: {
        foo: {
          namespaced: true,
          state: {barfoo: 'x'},
          mutations: {
            save (state, v) {
              state.barfoo = v
            },
          }
        }
      },              
    })
    this.$store.commit(`bar/foo/save`, 'new_content')