Fix: handle duplicate extensions included in search results

server/src/main/java/org/eclipse/openvsx/adapter/LocalVSCodeService.java

@@ -37,6 +37,7 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.*;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import static org.eclipse.openvsx.adapter.ExtensionQueryParam.Criterion.*;
@@ -145,7 +146,7 @@ public ExtensionQueryResult extensionQuery(ExtensionQueryParam param, int defaul
                         .collect(Collectors.toList());
 
                 var extensionsMap = repositories.findActiveExtensionsById(ids).stream()
-                        .collect(Collectors.toMap(e -> e.getId(), e -> e));
+                        .collect(Collectors.toMap(Extension::getId, e -> e));
 
                 // keep the same order as search results
                 extensionsList = ids.stream()
@@ -161,7 +162,9 @@ public ExtensionQueryResult extensionQuery(ExtensionQueryParam param, int defaul
         }
 
         var flags = param.flags();
-        var extensionsMap = extensionsList.stream().collect(Collectors.toMap(e -> e.getId(), e -> e));
+        // when mapping the list of extensions to a map, we need to handle duplicate entries which can happen,
+        // see https://github.com/eclipse/openvsx/issues/1394
+        var extensionsMap = extensionsList.stream().collect(Collectors.toMap(Extension::getId, Function.identity(), (a, b) -> a));
         List<ExtensionVersion> allActiveExtensionVersions = repositories.findActiveExtensionVersions(extensionsMap.keySet(), targetPlatform);
 
         List<ExtensionVersion> extensionVersions;
@@ -198,7 +201,7 @@ public ExtensionQueryResult extensionQuery(ExtensionQueryParam param, int defaul
 
             var idsMap = extensionVersionsMap.values().stream()
                     .flatMap(Collection::stream)
-                    .collect(Collectors.toMap(ev -> ev.getId(), ev -> ev));
+                    .collect(Collectors.toMap(ExtensionVersion::getId, ev -> ev));
 
             fileResources = repositories.findFileResourcesByExtensionVersionIdAndType(idsMap.keySet(), types).stream()
                     .map(r -> {

server/src/test/java/org/eclipse/openvsx/adapter/LocalVSCodeServiceTest.java

@@ -0,0 +1,140 @@
+/********************************************************************************
+ * Copyright (c) 2025 Eclipse Foundation and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ ********************************************************************************/
+package org.eclipse.openvsx.adapter;
+
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.eclipse.openvsx.cache.CacheService;
+import org.eclipse.openvsx.entities.Extension;
+import org.eclipse.openvsx.entities.ExtensionVersion;
+import org.eclipse.openvsx.entities.Namespace;
+import org.eclipse.openvsx.entities.SignatureKeyPair;
+import org.eclipse.openvsx.publish.ExtensionVersionIntegrityService;
+import org.eclipse.openvsx.repositories.RepositoryService;
+import org.eclipse.openvsx.search.SearchUtilService;
+import org.eclipse.openvsx.storage.*;
+import org.eclipse.openvsx.util.VersionService;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mockito;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import java.time.LocalDateTime;
+import java.util.Collections;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.eclipse.openvsx.adapter.ExtensionQueryParam.*;
+import static org.mockito.ArgumentMatchers.*;
+
+@ExtendWith(SpringExtension.class)
+@MockitoBean( types = {
+    VSCodeAPI.class, SimpleMeterRegistry.class, SearchUtilService.class,
+    VersionService.class, StorageUtilService.class, ExtensionVersionIntegrityService.class,
+    WebResourceService.class, CacheService.class
+})
+public class LocalVSCodeServiceTest {
+
+    @MockitoBean
+    RepositoryService repositories;
+
+    @MockitoBean
+    VersionService versions;
+
+    @Autowired
+    LocalVSCodeService vsCodeService;
+
+    @Test
+    void testDuplicateExtensionsInSearch() {
+        var extension = mockExtension();
+        var extensionVersion = mockExtensionVersion(extension, 1, "0.1.0", "linux");
+
+        var criterion = new ExtensionQueryParam.Criterion(Criterion.FILTER_EXTENSION_ID, "test-1");
+        var filter = new ExtensionQueryParam.Filter(List.of(criterion, criterion), 0, 0, 0, 0);
+        var param = new ExtensionQueryParam(List.of(filter), 0);
+
+        Mockito.when(repositories.findActiveExtensionsByPublicId(any(), any())).thenReturn(List.of(extension, extension));
+        Mockito.when(repositories.findActiveExtensionVersions(any(), any())).thenReturn(List.of(extensionVersion));
+        Mockito.when(versions.getLatest(anyList(), anyBoolean())).thenReturn(extensionVersion);
+
+        var result = vsCodeService.extensionQuery(param, 10);
+        assertThat(result.results()).hasSize(1);
+    }
+
+    // ---------- UTILITY ----------//
+
+    private Extension mockExtension() {
+        var namespace = new Namespace();
+        namespace.setId(2);
+        namespace.setPublicId("test-2");
+        namespace.setName("redhat");
+
+        var extension = new Extension();
+        extension.setId(1);
+        extension.setPublicId("test-1");
+        extension.setName("vscode-yaml");
+        extension.setAverageRating(3.0);
+        extension.setReviewCount(10L);
+        extension.setDownloadCount(100);
+        extension.setPublishedDate(LocalDateTime.parse("1999-12-01T09:00"));
+        extension.setLastUpdatedDate(LocalDateTime.parse("2000-01-01T10:00"));
+        extension.setNamespace(namespace);
+
+        return extension;
+    }
+
+    private ExtensionVersion mockExtensionVersion(Extension extension, long id, String version, String targetPlatform) {
+        var extVersion = new ExtensionVersion();
+        extVersion.setId(id);
+        extVersion.setVersion(version);
+        extVersion.setTargetPlatform(targetPlatform);
+        extVersion.setPreview(true);
+        extVersion.setTimestamp(LocalDateTime.parse("2000-01-01T10:00"));
+        extVersion.setDisplayName("YAML");
+        extVersion.setDescription("YAML Language Support");
+        extVersion.setEngines(List.of("vscode@^1.31.0"));
+        extVersion.setRepository("https://github.com/redhat-developer/vscode-yaml");
+        extVersion.setDependencies(Collections.emptyList());
+        extVersion.setBundledExtensions(Collections.emptyList());
+        extVersion.setLocalizedLanguages(Collections.emptyList());
+        extVersion.setExtension(extension);
+
+        var keyPair = new SignatureKeyPair();
+        keyPair.setPublicId("123-456-789");
+        extVersion.setSignatureKeyPair(keyPair);
+
+        return extVersion;
+    }
+
+    @TestConfiguration
+    static class TestConfig {
+        @Bean
+        VersionService versionService() {
+            return new VersionService();
+        }
+
+        @Bean
+        LocalVSCodeService vsCodeService(
+                RepositoryService repositories,
+                VersionService versions,
+                SearchUtilService search,
+                StorageUtilService storageUtil,
+                ExtensionVersionIntegrityService integrityService,
+                WebResourceService webResources,
+                CacheService cache
+        ) {
+            return new LocalVSCodeService(repositories, versions, search, storageUtil, integrityService, webResources, cache);
+        }
+    }
+
+}