feat: Add pre lookup check to DestinationService.tryGetDestination

cloudplatform/connectivity-destination-service/src/main/java/com/sap/cloud/sdk/cloudplatform/connectivity/DestinationService.java

@@ -1,5 +1,8 @@
 package com.sap.cloud.sdk.cloudplatform.connectivity;
 
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceOptionsAugmenter.getRetrievalStrategy;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceRetrievalStrategy.CURRENT_TENANT;
+
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -11,6 +14,7 @@
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.BiFunction;
 import java.util.function.Function;
+import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
@@ -122,9 +126,41 @@ static ResilienceConfiguration createResilienceConfiguration(
         Try<Destination>
         tryGetDestination( @Nonnull final String destinationName, @Nonnull final DestinationOptions options )
     {
+        final Option<Exception> validationError = validateDestinationLookup(destinationName, options);
+        if( validationError.isDefined() ) {
+            return Try.failure(validationError.get());
+        }
         return Cache.getOrComputeDestination(this, destinationName, options, this::loadAndParseDestination);
     }
 
+    Option<Exception> validateDestinationLookup( final String destinationName, final DestinationOptions options )
+    {
+        final Option<Exception> validLookup = Option.none();
+        if( !Cache.isEnabled() ) {
+            return validLookup;
+        }
+        if( !Cache.preLookupCheckEnabled ) {
+            return validLookup;
+        }
+        if( Cache.isUsingExperimentalFeatures(options) ) {
+            final String msg =
+                "Using pre-lookup check together with either fragments, cross-level options, or custom headers might lead to unexpected behaviour. Pre-lookup check is skipped.";
+            log.warn(msg);
+            return validLookup;
+        }
+
+        final DestinationServiceRetrievalStrategy strategy = getRetrievalStrategy(options).getOrElse(CURRENT_TENANT);
+        final Collection<DestinationProperties> cachedDestinations = getAllDestinationProperties(strategy);
+        final Predicate<DestinationProperties> pred = p -> p.get(DestinationProperty.NAME).contains(destinationName);
+        if( cachedDestinations.stream().anyMatch(pred) ) {
+            return validLookup;
+        }
+
+        final String msgFormat = "Destination %s was not found among the destinations for %s.";
+        final String msg = String.format(msgFormat, destinationName, strategy);
+        return Option.some(new DestinationNotFoundException(destinationName, msg));
+    }
+
     Destination loadAndParseDestination( final String destName, final DestinationOptions options )
         throws DestinationAccessException,
             DestinationNotFoundException
@@ -193,7 +229,7 @@ public Try<Iterable<Destination>> tryGetAllDestinations()
     @Nonnull
     public Collection<DestinationProperties> getAllDestinationProperties()
     {
-        return getAllDestinationProperties(DestinationServiceRetrievalStrategy.CURRENT_TENANT);
+        return getAllDestinationProperties(CURRENT_TENANT);
     }
 
     /**
@@ -428,6 +464,7 @@ public static final class Cache
 
         private static boolean cacheEnabled = true;
         private static boolean changeDetectionEnabled = true;
+        private static boolean preLookupCheckEnabled = true;
 
         static {
             recreateSingleCache();
@@ -445,6 +482,18 @@ static boolean isChangeDetectionEnabled()
             return changeDetectionEnabled;
         }
 
+        /**
+         * Disables checking if a destination exists before trying to call it directly when invoking
+         * {@link #tryGetDestination}. All available destinations can be found with
+         * {@link #getAllDestinationProperties}.
+         *
+         * @since 5.26.0
+         */
+        public static void disablePreLookupCheck()
+        {
+            preLookupCheckEnabled = false;
+        }
+
         @Nonnull
         static com.github.benmanes.caffeine.cache.Cache<CacheKey, Destination> instanceSingle()
         {
@@ -498,6 +547,7 @@ static void reset()
                 cacheEnabled = true;
             }
             changeDetectionEnabled = true;
+            preLookupCheckEnabled = true;
 
             sizeLimit = Option.some(DEFAULT_SIZE_LIMIT);
             expirationDuration = Option.some(DEFAULT_EXPIRATION_DURATION);
@@ -896,11 +946,15 @@ private static Try<List<DestinationProperties>> getOrComputeAllDestinations(
                 .execute();
         }
 
-        private static boolean isUsingExperimentalFeatures( @Nonnull final DestinationOptions options )
+        static boolean isUsingExperimentalFeatures( @Nonnull final DestinationOptions options )
         {
-            final String[] featureNames = { "X-fragment-name", "crossLevelSetting", "customHeader" };
+            final String[] featureNames =
+                {
+                    DestinationServiceOptionsAugmenter.X_FRAGMENT_KEY,
+                    DestinationServiceOptionsAugmenter.CROSS_LEVEL_SETTING_KEY,
+                    DestinationServiceOptionsAugmenter.CUSTOM_HEADER_KEY };
             final Set<String> keys = options.getOptionKeys();
-            return keys.stream().anyMatch(s -> Arrays.stream(featureNames).anyMatch(s::equalsIgnoreCase));
+            return keys.stream().anyMatch(s -> Arrays.stream(featureNames).anyMatch(s::startsWith));
         }
 
         private Cache()

cloudplatform/connectivity-destination-service/src/test/java/com/sap/cloud/sdk/cloudplatform/connectivity/DestinationServiceAuthenticationTest.java

@@ -66,6 +66,8 @@ void setMockAdapter()
             .when(mockAdapter)
             .getConfigurationAsJson(anyString(), any());
         sut = new DestinationService(mockAdapter);
+        // Disable PreLookupCheck to simplify test setup
+        DestinationService.Cache.disablePreLookupCheck();
     }
 
     @Test
@@ -290,7 +292,7 @@ void testOAuth2PasswordWithoutUserToken()
         assertThat(dest.asHttp().getHeaders())
             .containsExactlyInAnyOrder(new Header("Authorization", "Bearer " + oAuthToken));
 
-        verify(mockAdapter, times(1)).getConfigurationAsJson(anyString(), eq(expectedStrategy));
+        verify(mockAdapter, times(1)).getConfigurationAsJson(eq(SERVICE_PATH_DESTINATION), eq(expectedStrategy));
         verifyNoMoreInteractions(mockAdapter);
     }
 
@@ -382,7 +384,7 @@ void testSAPAssertionSSO()
         assertThat(dest.asHttp().getAuthenticationType()).isEqualTo(AuthenticationType.SAP_ASSERTION_SSO);
         assertThat(dest.asHttp().getHeaders()).containsExactlyInAnyOrder(new Header("Cookie", assertionCookie));
 
-        verify(mockAdapter, times(1)).getConfigurationAsJson(anyString(), eq(expectedStrategy));
+        verify(mockAdapter, times(1)).getConfigurationAsJson(eq(SERVICE_PATH_DESTINATION), eq(expectedStrategy));
         verifyNoMoreInteractions(mockAdapter);
     }
 

cloudplatform/connectivity-destination-service/src/test/java/com/sap/cloud/sdk/cloudplatform/connectivity/DestinationServiceCacheTest.java

@@ -1,11 +1,20 @@
 package com.sap.cloud.sdk.cloudplatform.connectivity;
 
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceOptionsAugmenter.augmenter;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceRetrievalStrategy.ALWAYS_PROVIDER;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceRetrievalStrategy.CURRENT_TENANT;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceRetrievalStrategy.ONLY_SUBSCRIBER;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceTokenExchangeStrategy.EXCHANGE_ONLY;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceTokenExchangeStrategy.FORWARD_USER_TOKEN;
+import static com.sap.cloud.sdk.cloudplatform.connectivity.DestinationServiceTokenExchangeStrategy.LOOKUP_ONLY;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatCode;
 
 import java.time.Duration;
+import java.util.Arrays;
 
 import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.parallel.Isolated;
 
@@ -14,6 +23,7 @@
 import com.sap.cloud.sdk.cloudplatform.resilience.CacheExpirationStrategy;
 
 import io.vavr.control.Option;
+import lombok.val;
 
 @Isolated( "Test interacts with global destination cache" )
 class DestinationServiceCacheTest
@@ -102,4 +112,38 @@ void testSize()
         assertThat(cacheSingle).isNotSameAs(DestinationService.Cache.instanceSingle());
         assertThat(cacheAll).isSameAs(DestinationService.Cache.instanceAll());
     }
+
+    @SuppressWarnings( "deprecation" )
+    @Test
+    @DisplayName( "Identification of experimental DestinationOptionsAugmenter settings in options" )
+    void testExperimentalSettingsIdentificationInOptions()
+    {
+        val experimentalAugmentersSet =
+            new DestinationServiceOptionsAugmenter[][] {
+                { augmenter().customHeaders(new Header("experimental-header", "value")) },
+                { augmenter().crossLevelConsumption(DestinationServiceOptionsAugmenter.CrossLevelScope.SUBACCOUNT) },
+                { augmenter().crossLevelConsumption(DestinationServiceOptionsAugmenter.CrossLevelScope.INSTANCE) },
+                { augmenter().fragmentName("a-fragment") } };
+
+        val legacyAugmentersSet =
+            new DestinationServiceOptionsAugmenter[][] {
+                {},
+                { augmenter().refreshToken("a-token") },
+                { augmenter().retrievalStrategy(ALWAYS_PROVIDER) },
+                { augmenter().tokenExchangeStrategy(FORWARD_USER_TOKEN) },
+                { augmenter().tokenExchangeStrategy(EXCHANGE_ONLY), augmenter().retrievalStrategy(CURRENT_TENANT) },
+                { augmenter().tokenExchangeStrategy(LOOKUP_ONLY), augmenter().retrievalStrategy(ONLY_SUBSCRIBER) } };
+
+        for( final DestinationServiceOptionsAugmenter[] legacyAugmenters : legacyAugmentersSet ) {
+            val b = DestinationOptions.builder();
+            Arrays.stream(legacyAugmenters).forEach(b::augmentBuilder);
+            assertThat(DestinationService.Cache.isUsingExperimentalFeatures(b.build())).isFalse();
+        }
+
+        for( final DestinationServiceOptionsAugmenter[] experimentalAugmenters : experimentalAugmentersSet ) {
+            val b = DestinationOptions.builder();
+            Arrays.stream(experimentalAugmenters).forEach(b::augmentBuilder);
+            assertThat(DestinationService.Cache.isUsingExperimentalFeatures(b.build())).isTrue();
+        }
+    }
 }

cloudplatform/connectivity-destination-service/src/test/java/com/sap/cloud/sdk/cloudplatform/connectivity/DestinationServicePrincipalPropagationTest.java

@@ -108,6 +108,9 @@ void setupConnectivity( @Nonnull final WireMockRuntimeInfo wm )
                 .withRequestBody(
                     equalTo("grant_type=client_credentials&client_secret=CLIENT_SECRET&client_id=CLIENT_ID"))
                 .willReturn(okJson("{\"access_token\":\"provider-client-credentials\",\"expires_in\":3600}")));
+
+        // Disable PreLookupCheck to simplify test setup
+        DestinationService.Cache.disablePreLookupCheck();
     }
 
     @AfterEach