How to mock the ApplicationContext in companion object in kotlin? - kotlin

Question

Help test a function that calls a class method.
There is a class whose field is initialized with a chain of methods appContext().getBean().
class ClassA {
private val employeeApi: EmployeeApi= appContext().getBean()
fun execute(): List<Employee> {
return employeeApi.method()
}
}
and for example there is a function for calls to class methods.
fun methodForTesting(params: ClassA .() -> Unit): List<Employee> {
return ClassA().apply(params).execute()
}
This function needs to be tested. How to do it?
Open access to the method in the file using
mockkStatic("com.company.MyFile")
Create a list of workers who need to be returned
Create a method stub
Calling the method
Checking data
#Test
fun `methodForTesting mockk`() {
mockkStatic("com.company.MyFile")
val classA : ClassA= Mockito.mock(ClassA::class.java)
val listEmployee: List<Employee> = listOf(Employee("Ivan"))
Mockito.`when`(classA.execute()).thenReturn(listEmployee)
val list : List<Employee> = methodForTesting(allAny())
Assertions.assertThat(list).isEqualTo(listEmployee)
}
If I write like this, then an error occurs. How can the solution be finalized?
Error:
kotlin.UninitializedPropertyAccessException: lateinit property FIELD has not been initialized
at Mockito.when(classA.execute()).thenReturn(listEmployee) <-- HERE
Configuration
EnableConfigurationProperties(HurmaProperties::class)
class AppConfig : ApplicationContextAware {
private var applicationContext: ApplicationContext? = null
override fun setApplicationContext(applicationContext: ApplicationContext) {
this.applicationContext = applicationContext
appCtx = applicationContext
}
#Bean
fun restTemplateBuilder(): RestTemplateBuilder = RestTemplateBuilder()
#Bean
fun restTemplate(builder: RestTemplateBuilder): RestTemplate =
builder.build()
companion object {
#JvmStatic
lateinit var appCtx: ApplicationContext
private set
}
}
fun appContext() = AppConfig.appCtx

Answer 1

I figured it out
If you call getBean() from the ApplicationContext, and you need to test some method, then do this:
var employeeApi = mock<EmployeeApi>()
every { appContext().getBean<EmployeeApi>() } returns employeeApi
every { employeeApi.method() } returns listEmployee
val resultList: List<Employee> = methodForTesting();