Ensure immutable @ConfigurationProperties instance can be replaced with @TestBean

[orrc]

I'm not exactly sure where the problem lies, but we have a test case that was running in Spring Boot 3.0.0, and fails with 3.0.2.

GitHub repo with a tiny reproduction: https://github.com/orrc/spring-boot-prop-binding-repro

---

With a @ConfigurationProperties class:

@ConfigurationProperties("app.my-config")
data class SomeConfig(
    val someProperty: Int,
)

And values in application.yml:

app:
  myConfig:
    someProperty: 1

Running this test, with an overridden config, fails to start:

@TestConfiguration
class SomeTestConfig {
    @Bean
    fun someConfig() = SomeConfig(
        someProperty = 2,
    )
}

@WebMvcTest(Controller::class)
@Import(SomeTestConfig::class)
class ControllerTest {
    @Test
    fun doNothing() {
        // Fails to start on Spring Boot 3.0.2
    }
}

---

Logs:

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'app.my-config' to com.example.demo.SomeConfig:

    Property: app.my-config.some-property
    Value: "1"
    Origin: class path resource [application.yml] - 3:19
    Reason: java.lang.IllegalStateException: No setter found for property: some-property


2023-01-24T22:44:22.453+01:00 ERROR 71630 --- [    Test worker] o.s.test.context.TestContextManager      : Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener] to prepare test instance [com.example.demo.ControllerTest@2e7af36e]

java.lang.IllegalStateException: Failed to load ApplicationContext for [WebMergedContextConfiguration@4a058df8 testClass = com.example.demo.ControllerTest, locations = [], classes = [com.example.demo.DemoApplication], contextInitializerClasses = [], activeProfiles = [], propertySourceLocations = [], propertySourceProperties = ["org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTestContextBootstrapper=true"], contextCustomizers = [org.springframework.boot.test.autoconfigure.OverrideAutoConfigurationContextCustomizerFactory$DisableAutoConfigurationContextCustomizer@6138e79a, org.springframework.boot.test.autoconfigure.actuate.observability.ObservabilityContextCustomizerFactory$DisableObservabilityContextCustomizer@9da1, org.springframework.boot.test.autoconfigure.filter.TypeExcludeFiltersContextCustomizer@7e546387, org.springframework.boot.test.autoconfigure.properties.PropertyMappingContextCustomizer@4c20d68, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverContextCustomizerFactory$Customizer@5f0e9815, [ImportsContextCustomizer@4b56b031 key = [com.example.demo.SomeTestConfig, org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration, org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration, org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration, org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration, org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration, org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration, org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration, org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration, org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration, org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration, org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration, org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration, org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration, org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration, org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration, org.springframework.boot.autoconfigure.web.servlet.HttpEncodingAutoConfiguration, org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcWebClientAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcWebDriverAutoConfiguration, org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientAutoConfiguration, org.springframework.boot.autoconfigure.security.oauth2.resource.servlet.OAuth2ResourceServerAutoConfiguration, org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration, org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration, org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration, org.springframework.boot.test.autoconfigure.web.servlet.MockMvcSecurityConfiguration, org.springframework.boot.test.autoconfigure.web.reactive.WebTestClientAutoConfiguration]], org.springframework.boot.test.context.filter.ExcludeFilterContextCustomizer@37091312, org.springframework.boot.test.json.DuplicateJsonObjectContextCustomizerFactory$DuplicateJsonObjectContextCustomizer@550a1967, org.springframework.boot.test.mock.mockito.MockitoContextCustomizer@0, org.springframework.boot.test.context.SpringBootTestAnnotation@19aa2405], resourceBasePath = "src/main/webapp", contextLoader = org.springframework.boot.test.context.SpringBootContextLoader, parent = null]
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:142) ~[spring-test-6.0.4.jar:6.0.4]
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:127) ~[spring-test-6.0.4.jar:6.0.4]
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:141) ~[spring-test-6.0.4.jar:6.0.4]
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:97) ~[spring-test-6.0.4.jar:6.0.4]
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:241) ~[spring-test-6.0.4.jar:6.0.4]
	at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:138) ~[spring-test-6.0.4.jar:6.0.4]
  …
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'controller' defined in file [/Users/chris/code/demo/build/classes/kotlin/main/com/example/demo/Controller.class]: Unsatisfied dependency expressed through constructor parameter 0: Error creating bean with name 'someConfig': Could not bind properties to 'SomeConfig' : prefix=app.my-config, ignoreInvalidFields=false, ignoreUnknownFields=true
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-6.0.4.jar:6.0.4]
	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:245) ~[spring-beans-6.0.4.jar:6.0.4]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1344) ~[spring-beans-6.0.4.jar:6.0.4]
  …
Caused by: org.springframework.boot.context.properties.ConfigurationPropertiesBindException: Error creating bean with name 'someConfig': Could not bind properties to 'SomeConfig' : prefix=app.my-config, ignoreInvalidFields=false, ignoreUnknownFields=true
	at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.bind(ConfigurationPropertiesBindingPostProcessor.java:99) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:79) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:420) ~[spring-beans-6.0.4.jar:6.0.4]
  …
Caused by: org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'app.my-config' to com.example.demo.SomeConfig
	at org.springframework.boot.context.properties.bind.Binder.handleBindError(Binder.java:387) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:347) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder.lambda$bindDataObject$4(Binder.java:472) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:98) ~[spring-boot-3.0.2.jar:3.0.2]
  …
Caused by: java.lang.IllegalStateException: No setter found for property: some-property
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:107) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:86) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:62) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder.lambda$bindDataObject$5(Binder.java:476) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:590) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder$Context.withDataObject(Binder.java:576) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder.bindDataObject(Binder.java:474) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:414) ~[spring-boot-3.0.2.jar:3.0.2]
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:343) ~[spring-boot-3.0.2.jar:3.0.2]
	... 140 common frames omitted

[orrc]

Annotating the config class constructor with @ConstructorBinding appears to make things work as they did in 3.0.0:

--- a/src/main/kotlin/com/example/demo/SomeConfig.kt
+++ b/src/main/kotlin/com/example/demo/SomeConfig.kt
@@ -3,5 +3,6 @@ package com.example.demo
 import org.springframework.boot.context.properties.ConfigurationProperties
+import org.springframework.boot.context.properties.bind.ConstructorBinding

 @ConfigurationProperties("app.my-config")
-data class SomeConfig(
+data class SomeConfig @ConstructorBinding constructor(
     val someProperty: Int,

[mhalbritter]

Could be related to #33849

[philwebb]

It might also be related to #33710

[travispeloton]

I don't think its working with 3.0.0 for me. I cannot override the default settings for the following in application.yml:

management:
  metrics:
    export:
      statsd:
        host: ${STATSD_HOST}
        enabled: true

The STATSD_HOST environment variable is never loaded as a property override. I tried using Java properties on the command line too and that didn't work.

Only the default settings are used. This works fine for me while using 2.x.

[philwebb]

@travispeloton Did you mean to comment on this issue? I'm not sure I see how your problem is related to Kotlin data classes.

[travispeloton]

This issue appeared relevant. I'm using Kotlin as well, and Spring 3.x wont allow me to configure the properties I mentioned in the comment above. It always uses the default values. There is something bigger broken here related to property binding.

[orrc]

@travispeloton This issue is specifically a regression in Spring Boot 3.0.2.

We are able to bind config properties and override them with environment variables at runtime in 3.0.x, so you should probably open a new issue with more details, including a minimal reproduction case, separate from statsd configuration.

[orrc]

After updating to Spring Boot 3.0.2, we were able to continue with the workaround above, and things worked fine.
Now that we're trying to update to Spring Boot 3.1.2, neither our original code nor the workaround works anymore.

This feels potentially similar to #36175, though the symptoms they were seeing seem to be different.
So I'm still a bit lost about exactly what the problem is, or whether we're just doing something completely wrong… 🤔

---

It should be possible reproduce with the GitHub repository mentioned above:

git clone https://github.com/orrc/spring-boot-prop-binding-repro
cd spring-boot-prop-binding-repro

✅ Succeeds with Spring Boot 3.0.1

Downgrade to 3.0.1 and run the tests:

sed -i 's/3.0.2/3.0.1/' build.gradle.kts

./gradlew test
# BUILD SUCCESSFUL

❌ Fails with Spring Boot 3.0.2

Reset to 3.0.2 and run the tests:

git checkout -- .

./gradlew test
# BUILD FAILED

✅ Succeeds with Spring Boot 3.0.2 + workaround

Apply the workaround to annotate the constructor with @ConstructorBinding, and run the tests:

patch -p1 << EOF
--- a/src/main/kotlin/com/example/demo/SomeConfig.kt
+++ b/src/main/kotlin/com/example/demo/SomeConfig.kt
@@ -3,0 +4 @@ import org.springframework.boot.context.properties.ConfigurationProperties
+import org.springframework.boot.context.properties.bind.ConstructorBinding
@@ -6 +7 @@ import org.springframework.boot.context.properties.ConfigurationProperties
-data class SomeConfig(
+data class SomeConfig @ConstructorBinding constructor(
EOF

./gradlew test
# BUILD SUCCESSFUL

✅ Succeeds with Spring Boot 3.1.0 + workaround

Upgrade to 3.1.0 and run the tests:

sed -i 's/3.0.2/3.1.0/' build.gradle.kts

./gradlew test
# BUILD SUCCESSFUL

❌ Fails with Spring Boot 3.1.1 + workaround

Upgrade to 3.1.1 and run the tests:

sed -i 's/3.1.0/3.1.1/' build.gradle.kts

./gradlew test
# BUILD FAILED

❌ Fails with Spring Boot 3.1.1, without workaround

Remove the workaround, and it still fails:

git checkout -- src/

./gradlew test
# BUILD FAILED

[wilkinsona]

This isn't specific to Kotlin. The same problem occurs with a Java class like this:

@ConfigurationProperties("app.myconfig")
public class SomeConfig {
	
	private final int someProperty;
	
	public SomeConfig(int someProperty) {
		this.someProperty = someProperty;
	}
	
	public int getSomeProperty() {
		return this.someProperty;
	}

}

Using @ConstructorBinding to prevent the attempt at JavaBean-based binding works up until 3.0.7 inclusive. I haven't tried every version, but it would appear that it never worked in 2.7.x. It either fails with the "no setter found" error or, when adding @ConstructorBinding, it fails because it has been added to a regular bean.

[rossLodge-R]

So I ran into this when trying to updated a project to 3.0.10 from 3.0.7. It appears to occur because spring instantiates the bean using the factory method (in the example repo, by calling SomeTestConfig.someConfig(), and then tries to modify the properties of the bean from the application.yml. Since the properties are indeed immutable, the attempt to modify them from the YAML file fails. That's probably as it should be, if it's meant to be immutable. I'm not sure how it worked prior to 3.0.8, but I assume that that spring was just not trying to apply the YAML. Maybe it should be fixed to revert to that behavior? At the least, a more helpful error message might be useful.

[Vignesh-Au]

I see the same issue with Kotlin data class when upgrading to spring-boot 3.1.5 from 2.7.12. I removed the @ConstructorBinding annotation as suggested in the 3.0 migration guide and started getting the error - Failed to bind properties under....

Can someone please confirm if this is being looked at?