Improve diagnostics when config prop value conversion fails

Closes gh-43378

Co-Authored-By: Phillip Webb <[email protected]>

Author: wilkinsona

Diff for: spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertySourcesPropertyResolver.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.context.properties.source;
 
+import org.springframework.core.convert.ConversionFailedException;
 import org.springframework.core.env.AbstractPropertyResolver;
 import org.springframework.core.env.MutablePropertySources;
 import org.springframework.core.env.PropertySources;
@@ -79,7 +80,14 @@ private <T> T getProperty(String key, Class<T> targetValueType, boolean resolveN
 		if (resolveNestedPlaceholders && value instanceof String string) {
 			value = resolveNestedPlaceholders(string);
 		}
-		return convertValueIfNecessary(value, targetValueType);
+		try {
+			return convertValueIfNecessary(value, targetValueType);
+		}
+		catch (ConversionFailedException ex) {
+			Exception wrappedCause = new InvalidConfigurationPropertyValueException(key, value,
+					"Failed to convert to type " + ex.getTargetType(), ex.getCause());
+			throw new ConversionFailedException(ex.getSourceType(), ex.getTargetType(), ex.getValue(), wrappedCause);
+		}
 	}
 
 	private Object findPropertyValue(String key) {

Diff for: spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/InvalidConfigurationPropertyValueException.java

@@ -43,7 +43,11 @@ public class InvalidConfigurationPropertyValueException extends RuntimeException
 	 * returns are allowed.
 	 */
 	public InvalidConfigurationPropertyValueException(String name, Object value, String reason) {
-		super("Property " + name + " with value '" + value + "' is invalid: " + reason);
+		this(name, value, reason, null);
+	}
+
+	InvalidConfigurationPropertyValueException(String name, Object value, String reason, Throwable cause) {
+		super("Property " + name + " with value '" + value + "' is invalid: " + reason, cause);
 		Assert.notNull(name, "Name must not be null");
 		this.name = name;
 		this.value = value;

Diff for: spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/source/ConfigurationPropertySourcesPropertyResolverTests.java

@@ -22,12 +22,15 @@
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.core.convert.ConversionFailedException;
+import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.core.env.ConfigurablePropertyResolver;
 import org.springframework.core.env.MutablePropertySources;
 import org.springframework.core.env.StandardEnvironment;
 import org.springframework.mock.env.MockPropertySource;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Tests for {@link ConfigurationPropertySourcesPropertyResolver}.
@@ -113,6 +116,30 @@ void getPropertyAsTypeWhenHasPlaceholder() {
 		assertThat(environment.getProperty("v2", Integer.class)).isOne();
 	}
 
+	@Test
+	void throwsInvalidConfigurationPropertyValueExceptionWhenGetPropertyAsTypeFailsToConvert() {
+		ResolverEnvironment environment = new ResolverEnvironment();
+		MockPropertySource propertySource = new MockPropertySource();
+		propertySource.withProperty("v1", "one");
+		propertySource.withProperty("v2", "${v1}");
+		environment.getPropertySources().addFirst(propertySource);
+		assertThat(environment.getProperty("v2")).isEqualTo("one");
+		assertThatExceptionOfType(ConversionFailedException.class)
+			.isThrownBy(() -> environment.getProperty("v2", Integer.class))
+			.satisfies((ex) -> {
+				assertThat(ex.getValue()).isEqualTo("one");
+				assertThat(ex.getSourceType()).isEqualTo(TypeDescriptor.valueOf(String.class));
+				assertThat(ex.getTargetType()).isEqualTo(TypeDescriptor.valueOf(Integer.class));
+			})
+			.havingCause()
+			.satisfies((ex) -> {
+				InvalidConfigurationPropertyValueException invalidValueEx = (InvalidConfigurationPropertyValueException) ex;
+				assertThat(invalidValueEx.getName()).isEqualTo("v2");
+				assertThat(invalidValueEx.getValue()).isEqualTo("one");
+				assertThat(ex).cause().isInstanceOf(NumberFormatException.class);
+			});
+	}
+
 	private CountingMockPropertySource createMockPropertySource(StandardEnvironment environment, boolean attach) {
 		CountingMockPropertySource propertySource = new CountingMockPropertySource();
 		propertySource.withProperty("spring", "boot");