Guard tests against versions with different metadata behavior for deleteVersionAfter.

Resolves see gh-432.

Author: mp911de

spring-vault-core/src/main/java/org/springframework/vault/support/VaultMetadataResponse.java

@@ -20,6 +20,8 @@
 import java.time.Period;
 import java.util.List;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Value object to bind Vault HTTP kv read metadata API responses.
  *
@@ -84,8 +86,9 @@ public int getCurrentVersion() {
 
 	/**
 	 * @return the duration after which a secret is to be deleted. {@link Period#ZERO} for
-	 * unlimited duration.
+	 * unlimited duration. Versions prior to Vault 1.2 may return {@code null}.
 	 */
+	@Nullable
 	public Duration getDeleteVersionAfter() {
 		return this.deleteVersionAfter;
 	}

spring-vault-core/src/test/java/org/springframework/vault/core/VaultKeyValueMetadataTemplateIntegrationTests.java

@@ -30,9 +30,22 @@
 import org.springframework.vault.support.VaultMetadataResponse;
 import org.springframework.vault.support.VaultResponse;
 import org.springframework.vault.support.Versioned;
+import org.springframework.vault.util.Version;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.vault.support.VaultMetadataRequest;
+import org.springframework.vault.support.VaultMetadataResponse;
+import org.springframework.vault.support.VaultResponse;
+import org.springframework.vault.support.Versioned;
+import org.springframework.vault.util.Version;
+
 /**
  * Integration tests for {@link VaultKeyValueMetadataOperations}.
  *
@@ -88,14 +101,19 @@ void shouldReadMetadataForANewKVEntry() {
 		assertThat(metadataResponse.getCurrentVersion()).isEqualTo(1);
 		assertThat(metadataResponse.getVersions()).hasSize(1);
 		assertThat(metadataResponse.isCasRequired()).isFalse();
-		assertThat(metadataResponse.getDeleteVersionAfter()).isEqualTo(Duration.ZERO);
 		assertThat(metadataResponse.getCreatedTime().isBefore(Instant.now())).isTrue();
 		assertThat(metadataResponse.getUpdatedTime().isBefore(Instant.now())).isTrue();
 
 		Versioned.Metadata version1 = metadataResponse.getVersions().get(0);
 
-		assertThat(version1.getDeletedAt()).isNull();
-		assertThat(version1.getCreatedAt()).isBefore(Instant.now());
+		if (prepare().getVersion().isGreaterThanOrEqualTo(Version.parse("1.2.0"))) {
+
+			assertThat(metadataResponse.getDeleteVersionAfter()).isEqualTo(Duration.ZERO);
+
+			assertThat(version1.getDeletedAt()).isNull();
+			assertThat(version1.getCreatedAt()).isBefore(Instant.now());
+		}
+
 		assertThat(version1.getVersion().getVersion()).isEqualTo(1);
 	}
 
@@ -130,7 +148,10 @@ void shouldUpdateKVMetadata() {
 
 		assertThat(metadataResponseAfterUpdate.isCasRequired()).isEqualTo(request.isCasRequired());
 		assertThat(metadataResponseAfterUpdate.getMaxVersions()).isEqualTo(request.getMaxVersions());
-		assertThat(metadataResponseAfterUpdate.getDeleteVersionAfter()).isEqualTo(duration);
+
+		if (prepare().getVersion().isGreaterThanOrEqualTo(Version.parse("1.2.0"))) {
+			assertThat(metadataResponseAfterUpdate.getDeleteVersionAfter()).isEqualTo(duration);
+		}
 	}
 
 	@Test