MobX 4.9.1 Cannot redefine property: snapshot

I have a:

1. Question
2. Documentation improvement
3. Issue:

• Provide error messages including stacktrace

Uncaught TypeError: Cannot redefine property: snapshot
    at Function.defineProperty (<anonymous>)
    at addReadOnlyProp (VM6409 mobx-state-tree.js:2758)
    at ObjectNode$$1.finalizeDeath (VM6409 mobx-state-tree.js:1416)
    at ObjectNode$$1.die (VM6409 mobx-state-tree.js:1393)
    at executeAction$$1 (VM6410 mobx.js:658)
    at ObjectNode$$1.res (VM6410 mobx.js:649)
    at reconcileArrayChildren (VM6409 mobx-state-tree.js:3554)
    at ArrayType$$1.willChange (VM6409 mobx-state-tree.js:3410)
    at interceptChange$$1 (VM6410 mobx.js:2809)
    at ObservableArrayAdministration.spliceWithArray (VM6410 mobx.js:2991)
    at ObservableArray$$1.replace (VM6410 mobx.js:3109)
    at ArrayType$$1.applySnapshot (VM6409 mobx-state-tree.js:3481)
    at executeAction$$1 (VM6410 mobx.js:658)
    at ArrayType$$1.res (VM6410 mobx.js:649)
    at eval (VM6409 mobx-state-tree.js:1383)
    at executeAction$$1 (VM6410 mobx.js:658)
    at res (VM6410 mobx.js:649)
    at runMiddleWares (VM6409 mobx-state-tree.js:2095)
    at runWithActionContext$$1 (VM6409 mobx-state-tree.js:1992)
    at ObjectNode$$1.res [as applySnapshot] (VM6409 mobx-state-tree.js:2015)
    at ArrayType$$1.ComplexType$$1.reconcile (VM6409 mobx-state-tree.js:1604)
    at OptionalValue$$1.reconcile (VM6409 mobx-state-tree.js:4662)
    at Array.ModelType$$1.willChange (VM6409 mobx-state-tree.js:3928)
    at interceptChange$$1 (VM6410 mobx.js:2809)
    at ObservableObjectAdministration$$1.write (VM6410 mobx.js:3958)
    at Object.set [as modelBArray] (VM6410 mobx.js:4132)
    at Object.populate2 (VM9727 index.js:28)
    at executeAction$$1 (VM6410 mobx.js:658)
    at res (VM6410 mobx.js:649)
    at runMiddleWares (VM6409 mobx-state-tree.js:2095)
    at runWithActionContext$$1 (VM6409 mobx-state-tree.js:1992)
    at res (VM6409 mobx-state-tree.js:2015)
    at Object.ReactErrorUtils.invokeGuardedCallback (VM6242 ReactErrorUtils.js:69)
    at executeDispatch (VM6241 EventPluginUtils.js:85)
    at Object.executeDispatchesInOrder (VM6241 EventPluginUtils.js:108)
    at executeDispatchesAndRelease (VM6239 EventPluginHub.js:43)
    at executeDispatchesAndReleaseTopLevel (VM6239 EventPluginHub.js:54)
    at Array.forEach (<anonymous>)
    at forEachAccumulated (VM6246 forEachAccumulated.js:24)
    at Object.processEventQueue (VM6239 EventPluginHub.js:257)
    at runEventQueueInBatch (VM6309 ReactEventEmitterMixin.js:17)
    at Object.handleTopLevel [as _handleTopLevel] (VM6309 ReactEventEmitterMixin.js:28)
    at handleTopLevelImpl (VM6370 ReactEventListener.js:72)
    at ReactDefaultBatchingStrategyTransaction.perform (VM6271 Transaction.js:140)
    at Object.batchedUpdates (VM6369 ReactDefaultBatchingStrategy.js:62)
    at Object.batchedUpdates (VM6256 ReactUpdates.js:97)
    at dispatchEvent (VM6370 ReactEventListener.js:147)

• Provide a minimal sample reproduction.

https://codesandbox.io/s/my14ymkvnx

Please first click on the first button then click on the second button then have a look at the console.

• Did you check this issue wasn’t filed before?
• Elaborate on your issue. What behavior did you expect?

The store should update correctly, instead the error state above is thrown.

• State the versions of MobX and relevant libraries. Which browser / node / … version?

This happens in 4.9.1 It neither happens in 4.8 nor in 5.8 (Unfortunately we had to downgrade to 4.x due to IE11 and SEO issues)

We are also using: mobx-react: 5.4.2 mobx-state-tree: 3.8.1

1. Idea:

• What problem would it solve for you?

Make it work without the error, as in previous versions

[alendit]

Related to https://github.com/mobxjs/mobx-state-tree/issues/1143 and fixed by https://github.com/mobxjs/mobx-state-tree/pull/1144 which is in mobx-state-tree 3.10.1. Your example works if you update mobx-state-tree version. I think it can be closed.

[lock[bot]]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs or questions.