Loading test application.yml properties - spring

Question

I have a test properties file under src/test/resources/application.yml. But I cannot get the values to load in my unit test. I have the following class:
#ConfigurationProperties("snmp")
open class SnmpProperties {
var port: Int = 1611
lateinit var protocol: String
lateinit var host: String
override fun toString(): String {
return "SnmpProperties(port=$port, protocol='$protocol', host='$host')"
}
}
which in the production code, loads in the values from /src/main/resources/application.yml.
snmp:
port: 1161
protocol: udp
host: 0.0.0.0
Unit test class:
#CamelSpringBootTest
#SpringBootApplication
#EnableAutoConfiguration
open class SnmpRouteTest : CamelTestSupport() {
#Autowired
lateinit var snmpProperties: SnmpProperties
#Mock
lateinit var repository: IPduEventRepository
#InjectMocks
lateinit var snmpTrapRoute: SnmpTrapRoute
#Before
fun setup() {
initMocks(this)
}
I have tried to add a test profile to each application.yml files to see if that adding #ActiveProfiles("test") worked, but it didn't.
src/main/resources/application.yml &
src/test/resources/application.yml
# Test profile
spring:
profiles: test
snmp:
port: 1161
protocol: udp
host: 0.0.0.0
I've also created a TestConfiguration class which creates the SnmpProperties bean and autowire it into the test class using #EnableConfigurationProperties(TestConfiguration::class):
#Configuration
#EnableConfigurationProperties(SnmpProperties::class)
open class TestConfiguration {
#Bean
open fun snmpProperties() = SnmpProperties()
}
Again, no go. The error I get is:
Cannot instantiate #InjectMocks field named 'snmpTrapRoute' of type 'class org.meanwhile.in.hell.camel.snmp.receiver.route.SnmpRoute'.
You haven't provided the instance at field declaration so I tried to construct the instance.
However the constructor or the initialization block threw an exception : Parameter specified as non-null is null: method org.meanwhile.in.hell.camel.snmp.receiver.route.SnmpTrapRoute.<init>, parameter snmpProperties

Answer 1

Make sure to check your project structure. The properties file should be on the classpath in order for Spring Boot to find and use it.
For example the project structure as defined by Maven here: https://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html
In case of Maven your configuration files should be put in these directories:
src/main/resources/application.yml
src/test/resources/application.yml

Answer 2

It looks like the bean is not created (hence the null error).
Try to either:
add #Configuration on top of your SnmpProperties configuration class
add #EnableConfigurationProperties(SnmpProperties.class) on top of your test class
Source: https://www.baeldung.com/configuration-properties-in-spring-boot

Answer 3

#CamelSpringBootTest
#SpringBootTest(classes = [SnmpTrapReceiverCamelApplication::class])
#DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
#DisableJmx(false)
#ExtendWith(MockitoExtension::class)
#EnableAutoConfiguration
class SnmpTrapRouteTest {
object TestSnmpConstants {
const val SNMP_REAL_ENDPOINT_ID = "snmp-trap-route"
const val SNMP_DIRECT_REPLACEMENT_ENDPOINT = "direct:snmp-from"
const val TRAP_REQUEST_ID = 123456789
const val TRAP_OID = "1.2.3.4.5"
const val TRAP_PAYLOAD = "snmp-trap-payload"
}
#MockBean
lateinit var repository: IPduEventRepository
#Produce
lateinit var producerTemplate: ProducerTemplate
#Autowired
lateinit var camelContext: CamelContext
#Test
#Throws(Exception::class)
fun `Should call save method on the repository when PDU TRAP event supplied`() {
// Replace our SNMP consumer route with a dummy route than can be called from a producer internally.
// Since our snmp endpoint is an asynchronous consumer (meaning it only receives data from external events)
// we need to use the "direct:" component to allow a producer to internally call what is ordinarily an external
// event-driven endpoint. Otherwise we will get a Connection Refused error, as we cannot access the external
// system/socket.
AdviceWithRouteBuilder.adviceWith(camelContext, TestSnmpConstants.SNMP_REAL_ENDPOINT_ID) { routeBuilder ->
routeBuilder.replaceFromWith(TestSnmpConstants.SNMP_DIRECT_REPLACEMENT_ENDPOINT)
}
// Create the PDU object to send to the SNMP endpoint
val trap = PDU()
trap.type = PDU.TRAP
trap.requestID = Integer32(TestSnmpConstants.TRAP_REQUEST_ID)
trap.add(VariableBinding(OID(TestSnmpConstants.TRAP_OID), OctetString(TestSnmpConstants.TRAP_PAYLOAD)))
// "direct:" endpoints only send DefaultMessage objects. These are not castable to SnmpMessage objects,
// so need to overwrite the exchange IN message to be an SnmpMessage object
val exchange = DefaultExchange(camelContext)
exchange.setIn(SnmpMessage(camelContext, trap))
// ProducerTemplates need a default endpoint specified.
// The ProducerTemplate provides us with a producer that can directly deliver messages to consumers defined
// in the camelContext, using the "direct:" component (see above)
producerTemplate.setDefaultEndpointUri(TestSnmpConstants.SNMP_DIRECT_REPLACEMENT_ENDPOINT)
producerTemplate.send(exchange)
// Verify that the repository.save() was invoked
verify(repository, atLeast(1)).save(any())
}
}