How to apply snapshots with an array of references to an existing node?

[patrickschmelter]

The first time while fetching a node from the database the model gets created with Model.create(snapshot) and it works fine. The Snapshot has an empty array of references to another model. However after refreshing the same said model, an exception is thrown:

Uncaught Error Error: [mobx-state-tree] A node cannot exists twice in the state tree. Failed to add reference(late(() => OtherModel["default"]))[]@/otherModels to path '/models/0/otherModels'.

Model

const Model = types.model({
    id: types.identifier,
    otherModels: types.array(types.reference(types.late((): IAnyModelType => OtherModel))), // https://mobx-state-tree.js.org/tips/circular-deps
});

OtherModel

const OtherModel = types.model({
    id: types.identifier,
});

Update logic

const presentEntity = self.getListForEntity(entityUpdate).find((e) => e.id === entityUpdate.id);
if (presentEntity) {
    applySnapshot(presentEntity, entityUpdate);
} else {
    self.getListForEntity(entityUpdate).push(entityUpdate);
}

[patrickschmelter]

Seems to be working now. My mistake was to apply a node to a node. My repository already creates models and passes them to the update logic. With changing the update line to applySnapshot(presentEntity, getSnapshot(entityUpdate)) it started working :) Still leaving this discussion here because I couldn't find somebody else online to do something similar.