Consider aliases when checking descendants

Update `AliasedConfigurationPropertySource` to consider aliases in
`containsDescendantOf`.

Prior to this commit, given a source containing `example.name` with
a defined alias of `other.name -> example.name` calling
`containsDescendantOf("other")` would incorrectly return
`ConfigurationPropertyState.ABSENT`.

Closes gh-14967

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/AliasedConfigurationPropertySource.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.context.properties.source;
 
+import java.util.Set;
+
 import org.springframework.util.Assert;
 
 /**
@@ -58,11 +60,17 @@ class AliasedConfigurationPropertySource implements ConfigurationPropertySource
 		if (result != ConfigurationPropertyState.ABSENT) {
 			return result;
 		}
-		for (ConfigurationPropertyName alias : getAliases().getAliases(name)) {
-			ConfigurationPropertyState aliasResult = this.source
-					.containsDescendantOf(alias);
-			if (aliasResult != ConfigurationPropertyState.ABSENT) {
-				return aliasResult;
+		Set<ConfigurationPropertyName> aliasNames = this.aliases.getAllNames();
+		for (ConfigurationPropertyName configurationPropertyName : aliasNames) {
+			boolean descendantPresentInAlias = this.aliases
+					.getAliases(configurationPropertyName).stream()
+					.filter(name::isAncestorOf).findFirst().isPresent();
+			if (descendantPresentInAlias) {
+				ConfigurationProperty configurationProperty = this.getSource()
+						.getConfigurationProperty(configurationPropertyName);
+				if (configurationProperty != null) {
+					return ConfigurationPropertyState.PRESENT;
+				}
 			}
 		}
 		return ConfigurationPropertyState.ABSENT;

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyNameAliases.java

@@ -20,6 +20,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedMultiValueMap;
@@ -74,4 +75,8 @@ public final class ConfigurationPropertyNameAliases {
 				.findFirst().orElse(null);
 	}
 
+	public Set<ConfigurationPropertyName> getAllNames() {
+		return this.aliases.keySet();
+	}
+
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/source/AliasedConfigurationPropertySourceTests.java

@@ -19,6 +19,8 @@ package org.springframework.boot.context.properties.source;
 import org.junit.Test;
 import org.mockito.Answers;
 
+import org.springframework.boot.origin.Origin;
+
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
@@ -105,8 +107,30 @@ public class AliasedConfigurationPropertySourceTests {
 				.willReturn(ConfigurationPropertyState.ABSENT);
 		given(source.containsDescendantOf(ConfigurationPropertyName.of("bar")))
 				.willReturn(ConfigurationPropertyState.PRESENT);
+		ConfigurationPropertyName barBar = ConfigurationPropertyName.of("bar.bar");
+		given(source.getConfigurationProperty(barBar)).willReturn(
+				new ConfigurationProperty(barBar, "barBarValue", mock(Origin.class)));
 		ConfigurationPropertySource aliased = source
-				.withAliases(new ConfigurationPropertyNameAliases("foo", "bar"));
+				.withAliases(new ConfigurationPropertyNameAliases("bar.bar", "foo.foo"));
+		assertThat(aliased.containsDescendantOf(name))
+				.isEqualTo(ConfigurationPropertyState.PRESENT);
+	}
+
+	@Test
+	public void containsDescendantOfWhenPresentInAliasShouldReturnPresent() {
+		ConfigurationPropertyName name = ConfigurationPropertyName.of("baz");
+		ConfigurationPropertySource source = mock(ConfigurationPropertySource.class,
+				withSettings().defaultAnswer(Answers.CALLS_REAL_METHODS));
+		given(source.containsDescendantOf(name))
+				.willReturn(ConfigurationPropertyState.ABSENT);
+
+		ConfigurationPropertyName barFoo = ConfigurationPropertyName.of("bar.foo");
+
+		given(source.getConfigurationProperty(barFoo)).willReturn(
+				new ConfigurationProperty(barFoo, "barFooValue", mock(Origin.class)));
+
+		ConfigurationPropertySource aliased = source
+				.withAliases(new ConfigurationPropertyNameAliases("bar.foo", "baz.foo"));
 		assertThat(aliased.containsDescendantOf(name))
 				.isEqualTo(ConfigurationPropertyState.PRESENT);
 	}