Can't load a test-properties.yaml file with the @TestPropertySource with Spring Boot, JUnit5 and Kotlin

Question

I have a class that is injected with the application.yaml properties located in the src/main/resources directory. I wrote a test that is asserting if those properties are injected as expected. The test does work fine but it is using the application.yaml file from src/main/resources.

I want it to use the test-application.yaml file from src/test/resources to use some bogus values.

I followed many guides and read many questions here on Stackoverflow but could not get any of those approaches to work. Maybe because I mixed up different solution's annotations or whatever.

Status Quo

I am using the spring versions provided by the spring management system

    id("io.spring.dependency-management") version "1.0.9.RELEASE"

Edit: Also I use the following relevant dependencies:

    testImplementation("org.springframework.boot:spring-boot-starter-test") {
        exclude(group = "org.junit.vintage", module = "junit-vintage-engine")
    }
    annotationProcessor("org.springframework.boot:spring-boot-configuration-processor")
    implementation("org.springframework.boot:spring-boot-starter-actuator")
    implementation("org.springframework.boot:spring-boot-starter-webflux")

The property file src/main/resources/application.yaml:

controlroom:
  ftpConnections:
    foo-importer:
      host: ftp.stage.company.com
      port: 22
      user: foo-ftp
      password: password
    bar-importer:
      host: ftp.stage.company.com
      port: 22
      user: bar-ftp
      password: password

This is the property configuration holder class:

@Configuration
@ConfigurationProperties(prefix = "controlroom")
class FtpConnectionsProvider(
) {
    lateinit var ftpConnections: Map<String, Map<String, String>>
}

And this is the test class that currently is injecting the properties from main/resources/application.yaml:

@ExtendWith(SpringExtension::class)
@SpringBootTest
internal class FtpConnectionsProviderTest(
        @Autowired
        val ftpConnectionsProvider: FtpConnectionsProvider
) {
    @Test
    fun `should fill FtpConnectionsProvider with properties from yaml`() {
        assertThat(ftpConnectionsProvider.ftpConnections["foo-importer"]).containsAllEntriesOf(
                mapOf(
                        "host" to "ftp.stage.company.com",
                        "port" to "22",
                        "user" to "foo-ftp",
                        "password" to "password"
                ))
        assertThat(ftpConnectionsProvider.ftpConnections["bar-importer"]).containsAllEntriesOf(
                mapOf(
                        "host" to "ftp.stage.company.com",
                        "port" to "22",
                        "user" to "bar-ftp",
                        "password" to "password"
                ))
    }
}

How to use the test-application.yaml ?

Now I wonder how I can give the test the instruction to only use src/test/resources/test-application.yaml.

First Try

@ExtendWith(SpringExtension::class)
@SpringBootTest
@TestPropertySource("classpath:test-application.yaml")
internal class FtpConnectionsProviderTest

Result: Just ignores it and keeps using src/main/resources/application.yaml

Second Try

People say that @TestPropertySource can't read .yaml files and therefore I added the @ContextConfiguration annotation since this was the suggested fix.

@ExtendWith(SpringExtension::class)
@SpringBootTest
@TestPropertySource("classpath:test-application.yaml")
@ContextConfiguration(initializers=[ConfigFileApplicationContextInitializer::class])
internal class FtpConnectionsProviderTest

Result: Just ignores it and keeps using src/main/kotlin/resources/application.yaml

Nothing seems to work. I do not grasp why this is such a big deal and why it is so complicated to find a solution

Answer 1

You cannot load yaml file using @TestPropertySource.

Answer 2

Have you tried placing a application.yaml file under src/test/kotlin/resources? That should work without any special config / annotations.

Also, if you want to have / override certain properties within a yaml file called testfoo, you can place these props in a application-testfoo.yaml in the same directory, and the file will be used if you activate a testfoo Spring profile.

Example:

src/test/kotlin/resources/application.yaml:

controlroom:
  ftpConnections:
    foo-importer:
      host: ftp.stage.company.com
      port: 22
      user: foo-ftp
      password: password
    bar-importer:
      host: ftp.stage.company.com
      port: 22
      user: bar-ftp
      password: password

src/test/kotlin/resources/application-testfoo.yaml:

controlroom:
  ftpConnections:
    foo-importer:
      user: test-foo-ftp

If you active the testfoo profile, controlroom.ftpConnections.foo-importer.user will be overridden. Is that what you want?

Alternatively, as an even simpler solution if you just want to replace a couple of your production prop values: Don't create a src/test/kotlin/resources/application.yaml at all. Just create the src/test/kotlin/resources/application-testfoo.yaml and it should override the values from src/main/kotlin/resources/application.yaml (assuming the testfoo profile is active)! That works in Java with my applications.properties anyways - I see no reason why it should work any differently in Kotlin.