android - 如何使用 Hilt 模拟 View 模型以进行单元测试 fragment ？

Question

我有一个使用 Hilt 进行依赖注入(inject)的 android 应用程序设置，并且想对我的 fragment 进行单元测试。
我目前正在使用以下方法创建我的 View 模型:

private val viewModel: ExampleViewModel by viewModels()

我正在使用 here 中的代码创建用于测试的 fragment
我需要用一个模拟替换这个 ExampleViewModel，我该怎么做呢？

Answer 1

我将在与您的问题相关的问题 (https://github.com/google/dagger/issues/1972) 中粘贴“danysantiago”回复:

Hilt ViewModel extension works by declaring modules that bind assistedfactories to a map and not by binding concrete ViewModels. Therefore,what you want to do is bind the assisted factory of the concreteViewModel using the key of the abstract ViewModel so that whenHiltViewModelFactory looks up the factory based on class key it usesthe assisted factory for the concrete ViewModel. This is suuuperobscure and hence why I mean not 'easily' available.

However, if you can expand on the test case your are trying to writethat could help us provide some guidance, I'm not sure if you aretrying to mock/fake the ViewModel itself for tests, but Hilt testingAPIs should allow you to replace dependencies in the ViewModel so youcan write a test with the Fragment and the ViewModel.