如何在角度2+中避免单元测试的依赖性

Question

i see lots of examples about how to unit test simple components in angular 2+, but when it comes to test components who use services, it becomes a nightmare to maintain the test bed providers and imports. how can i avoid it ?

for example i have myComponents, who uses myService, who uses HttpClient. To test myComponent i must setup the providers for myService and HttpClient. If i add an other service to the constructor of myService, i will have to edit ALL the testbeds of the cmoponents who use this service.

can't i tell the testbed to fetch the default dependencies for these modules?

Answer 1

The problem results from wrong testing methodology. Unit testing is about testing single units.

In this scenario

myComponents, who uses myService, who uses HttpClient. To test myComponent i must setup the providers for myService and HttpClient.

it is myComponent unit that it tested. This means that any other unit should be mocked or stubbed, including myService .

While this

fetch the default dependencies for these modules

is considered not unit but integration/e2e test.