How to mock model when testing setupController or private Route methods - unit-testing

Question

When I try to mock model by writing let mockModel = this.owner.lookup('model:realModel'); in my route (unit) test, I receive the error
Error: You should not call 'create' on a model. Instead, call 'store.createRecord' with the attributes you would like to set.
What's the proper way to mock model to test processing within setupController and other private route methods?
Code to illustrate testing setupController/private route methods:
app\routes\application.js
export default Route.extend({
_postModelProcessing(inputModel){
....
return processedModelData;
},
setupController(controller, model){
let processedModelData = _postModelProcessing(model);
}
})
tests\unit\routes\application-test.js
module('Unit | Route | application', function(hooks) {
setupTest(hooks);
...
test('private _postModelProcessing correctly processes model data', function(assert) {
let route = this.owner.lookup('route:application');
// This line throws the Error mentioned above
let mockModel = this.owner.lookup('model:realModel');
// what I hoped to do, if the above line didn't throw an error:
let mockModelData = [
mockModel.create({
category: 'Leopard',
childCategories: [],
parentCategory: null
}),
mockModel.create({
category: 'Snow Leopard',
childCategories: [],
parentCategory: 'Leopard'
}),
mockModel.create({
category: 'Persian Leopard',
childCategories: [],
parentCategory: 'Leopard'
})
]
let processedData = route._postModelProcessing(mockModelData);
let leopardFirstChild = processedData[0].get('childCategories')[0];
assert.equal(leopardFirstChild.get('category'), 'Snow Leopard');
})
});

Answer 1

Just what the error message says, use store.createRecord:
module('Unit | Route | application', function(hooks) {
setupTest(hooks);
...
test('private _postModelProcessing correctly processes model data', function(assert) {
let route = this.owner.lookup('route:application');
let store = this.owner.lookup('service:store');
// what I hoped to do, if the above line didn't throw an error:
let mockModelData = [
store.createRecord('real-model', {
category: 'Leopard',
childCategories: [],
parentCategory: null
}),
store.createRecord('real-model', {
category: 'Snow Leopard',
childCategories: [],
parentCategory: 'Leopard'
}),
store.createRecord('real-model', {
category: 'Persian Leopard',
childCategories: [],
parentCategory: 'Leopard'
})
]
let processedData = route._postModelProcessing(mockModelData);
let leopardFirstChild = processedData[0].get('childCategories')[0];
assert.equal(leopardFirstChild.get('category'), 'Snow Leopard');
})
});