diff --git a/sdk/fabric/azure-resourcemanager-fabric/pom.xml b/sdk/fabric/azure-resourcemanager-fabric/pom.xml
index 7a77f7f6000d4..ce4f5692fb686 100644
--- a/sdk/fabric/azure-resourcemanager-fabric/pom.xml
+++ b/sdk/fabric/azure-resourcemanager-fabric/pom.xml
@@ -66,7 +66,7 @@
     <dependency>
       <groupId>com.azure</groupId>
       <artifactId>azure-core-test</artifactId>
-      <version>1.26.2</version> <!-- {x-version-update;com.azure:azure-core-test;dependency} -->
+      <version>1.27.0-beta.1</version> <!-- {x-version-update;com.azure:azure-core-test;dependency} -->
       <scope>test</scope>
     </dependency>
     <dependency>
diff --git a/sdk/search/azure-search-documents/src/main/java/com/azure/search/documents/SearchClientBuilder.java b/sdk/search/azure-search-documents/src/main/java/com/azure/search/documents/SearchClientBuilder.java
index dda9e3e24d770..c2ff43c386bd8 100644
--- a/sdk/search/azure-search-documents/src/main/java/com/azure/search/documents/SearchClientBuilder.java
+++ b/sdk/search/azure-search-documents/src/main/java/com/azure/search/documents/SearchClientBuilder.java
@@ -330,8 +330,7 @@ private HttpPipeline getHttpPipeline() {
      * Sets the service endpoint for the Azure AI Search instance.
      *
      * @param endpoint The URL of the Azure AI Search instance.
-     * @return The updated SearchClientBuilder object.
-     * @throws IllegalArgumentException If {@code endpoint} is null or it cannot be parsed into a valid URL.
+     * @return The updated SearchClientBuilder object.0ed into a valid URL.
      */
     @Override
     public SearchClientBuilder endpoint(String endpoint) {
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchClientBuilderTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchClientBuilderTests.java
index 5b9c5febcd4ae..14b5d91006603 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchClientBuilderTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchClientBuilderTests.java
@@ -47,6 +47,7 @@ public void buildSyncClientTest() {
             .credential(SEARCH_CREDENTIAL)
             .indexName(INDEX_NAME)
             .serviceVersion(API_VERSION)
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildClient();
 
         assertNotNull(client);
@@ -59,6 +60,7 @@ public void buildSyncClientUsingDefaultApiVersionTest() {
             .endpoint(SEARCH_ENDPOINT)
             .credential(SEARCH_CREDENTIAL)
             .indexName(INDEX_NAME)
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildClient();
 
         assertNotNull(client);
@@ -72,6 +74,7 @@ public void buildAsyncClientTest() {
             .credential(SEARCH_CREDENTIAL)
             .indexName(INDEX_NAME)
             .serviceVersion(API_VERSION)
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildAsyncClient();
 
         assertNotNull(client);
@@ -84,6 +87,7 @@ public void buildAsyncClientUsingDefaultApiVersionTest() {
             .endpoint(SEARCH_ENDPOINT)
             .credential(SEARCH_CREDENTIAL)
             .indexName(INDEX_NAME)
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildAsyncClient();
 
         assertNotNull(client);
@@ -96,6 +100,7 @@ public void whenBuildClientAndVerifyPropertiesThenSuccess() {
             .endpoint(SEARCH_ENDPOINT)
             .credential(SEARCH_CREDENTIAL)
             .indexName(INDEX_NAME)
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildClient();
 
         assertEquals(SEARCH_ENDPOINT, client.getEndpoint());
@@ -105,6 +110,7 @@ public void whenBuildClientAndVerifyPropertiesThenSuccess() {
             .endpoint(SEARCH_ENDPOINT)
             .credential(SEARCH_CREDENTIAL)
             .indexName(INDEX_NAME)
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildAsyncClient();
 
         assertEquals(SEARCH_ENDPOINT, asyncClient.getEndpoint());
@@ -214,6 +220,7 @@ public void bothRetryOptionsAndRetryPolicySet() {
             .serviceVersion(API_VERSION)
             .retryOptions(new RetryOptions(new ExponentialBackoffOptions()))
             .retryPolicy(new RetryPolicy())
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .buildClient());
     }
 }
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchIndexingBufferedSenderUnitTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchIndexingBufferedSenderUnitTests.java
index 139477e519b0e..97650258d089b 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchIndexingBufferedSenderUnitTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchIndexingBufferedSenderUnitTests.java
@@ -923,6 +923,7 @@ public void batchSplitsUntilOneAndPartiallyFailsAsync() {
     public void operationsThrowAfterClientIsClosed(
         Consumer<SearchIndexingBufferedSender<Map<String, Object>>> operation) {
         SearchIndexingBufferedSender<Map<String, Object>> batchingClient = getSearchClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .bufferedSender(HOTEL_DOCUMENT_TYPE)
             .documentKeyRetriever(HOTEL_ID_KEY_RETRIEVER)
             .autoFlush(false)
@@ -968,6 +969,7 @@ static Stream<Consumer<SearchIndexingBufferedSender<Map<String, Object>>>> opera
     public void operationsThrowAfterClientIsClosedAsync(
         Function<SearchIndexingBufferedAsyncSender<Map<String, Object>>, Mono<Void>> operation) {
         SearchIndexingBufferedAsyncSender<Map<String, Object>> batchingClient = getSearchClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .bufferedSender(HOTEL_DOCUMENT_TYPE)
             .documentKeyRetriever(HOTEL_ID_KEY_RETRIEVER)
             .autoFlush(false)
@@ -999,6 +1001,7 @@ static Stream<Function<SearchIndexingBufferedAsyncSender<Map<String, Object>>, M
     @Test
     public void closingTwiceDoesNotThrow() {
         SearchIndexingBufferedSender<Map<String, Object>> batchingClient = getSearchClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .bufferedSender(HOTEL_DOCUMENT_TYPE)
             .documentKeyRetriever(HOTEL_ID_KEY_RETRIEVER)
             .autoFlush(false)
@@ -1012,6 +1015,7 @@ public void closingTwiceDoesNotThrow() {
     @Test
     public void closingTwiceDoesNotThrowAsync() {
         SearchIndexingBufferedAsyncSender<Map<String, Object>> batchingClient = getSearchClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .bufferedSender(HOTEL_DOCUMENT_TYPE)
             .documentKeyRetriever(HOTEL_ID_KEY_RETRIEVER)
             .autoFlush(false)
@@ -1453,6 +1457,7 @@ public void delayResetsAfterNo503sAsync() {
     public void emptyBatchIsNeverSent() {
         AtomicInteger requestCount = new AtomicInteger();
         SearchIndexingBufferedSender<Map<String, Object>> batchingClient = getSearchClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .addPolicy((context, next) -> {
                 requestCount.incrementAndGet();
                 return next.process();
@@ -1474,6 +1479,7 @@ public void emptyBatchIsNeverSent() {
     public void emptyBatchIsNeverSentAsync() {
         AtomicInteger requestCount = new AtomicInteger();
         SearchIndexingBufferedAsyncSender<Map<String, Object>> batchingClient = getSearchClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .addPolicy((context, next) -> {
                 requestCount.incrementAndGet();
                 return next.process();
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchServiceSubClientTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchServiceSubClientTests.java
index a45c5cdd456db..3a03d2aac7a8a 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchServiceSubClientTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/SearchServiceSubClientTests.java
@@ -6,11 +6,13 @@
 import com.azure.core.http.HttpPipeline;
 import com.azure.core.http.policy.FixedDelay;
 import com.azure.core.http.policy.RetryPolicy;
+import com.azure.core.test.http.MockHttpResponse;
 import com.azure.search.documents.indexes.IndexesTestHelpers;
 import com.azure.search.documents.indexes.SearchIndexAsyncClient;
 import com.azure.search.documents.indexes.SearchIndexClient;
 import com.azure.search.documents.indexes.SearchIndexClientBuilder;
 import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
 import java.time.Duration;
@@ -96,6 +98,7 @@ private SearchIndexClient getSearchIndexClient() {
 
     private SearchIndexClient getSearchIndexClient(RetryPolicy retryPolicy) {
         return new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint("https://test1.search.windows.net")
             .credential(new AzureKeyCredential("api-key"))
             .retryPolicy(retryPolicy)
@@ -104,6 +107,7 @@ private SearchIndexClient getSearchIndexClient(RetryPolicy retryPolicy) {
 
     private SearchIndexAsyncClient getSearchIndexAsyncClient() {
         return new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint("https://test1.search.windows.net")
             .credential(new AzureKeyCredential("api-key"))
             .buildAsyncClient();
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexManagementTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexManagementTests.java
index ffbd738861eaf..e213d78475ffa 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexManagementTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexManagementTests.java
@@ -67,16 +67,18 @@ public class IndexManagementTests extends SearchTestBase {
 
     @BeforeAll
     public static void setupSharedResources() {
+        sharedSynonymMap = new SynonymMap("sharedhotelmotel").setSynonyms("hotel,motel");
+
+        if (TEST_MODE == TestMode.PLAYBACK) {
+            return;
+        }
+
         sharedIndexClient = new SearchIndexClientBuilder()
             .endpoint(ENDPOINT)
             .credential(TestHelpers.getTestTokenCredential())
             .buildClient();
 
-        sharedSynonymMap = new SynonymMap("sharedhotelmotel").setSynonyms("hotel,motel");
-
-        if (TEST_MODE != TestMode.PLAYBACK) {
-            sharedSynonymMap = sharedIndexClient.createSynonymMap(sharedSynonymMap);
-        }
+        sharedSynonymMap = sharedIndexClient.createSynonymMap(sharedSynonymMap);
     }
 
     @AfterAll
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexersManagementTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexersManagementTests.java
index 7172edb8f1216..b410564f9a17b 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexersManagementTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/IndexersManagementTests.java
@@ -121,6 +121,14 @@ private void createAndValidateIndexerAsync(SearchIndexer indexer) {
 
     @BeforeAll
     public static void setupSharedResources() {
+        sharedSkillset = createSkillsetObject();
+        sharedDatasource = createSharedDataSource();
+        sharedIndex = createTestIndexForLiveDatasource();
+
+        if (TEST_MODE == TestMode.PLAYBACK) {
+            return;
+        }
+
         sharedIndexerClient = new SearchIndexerClientBuilder()
             .endpoint(ENDPOINT)
             .credential(TestHelpers.getTestTokenCredential())
@@ -130,15 +138,9 @@ public static void setupSharedResources() {
             .credential(TestHelpers.getTestTokenCredential())
             .buildClient();
 
-        sharedSkillset = createSkillsetObject();
-        sharedDatasource = createSharedDataSource();
-        sharedIndex = createTestIndexForLiveDatasource();
-
-        if (TEST_MODE != TestMode.PLAYBACK) {
-            sharedSkillset = sharedIndexerClient.createSkillset(sharedSkillset);
-            sharedDatasource = sharedIndexerClient.createOrUpdateDataSourceConnection(sharedDatasource);
-            sharedIndex = sharedIndexClient.createIndex(sharedIndex);
-        }
+        sharedSkillset = sharedIndexerClient.createSkillset(sharedSkillset);
+        sharedDatasource = sharedIndexerClient.createOrUpdateDataSourceConnection(sharedDatasource);
+        sharedIndex = sharedIndexClient.createIndex(sharedIndex);
     }
 
     @AfterAll
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/NonRestCallTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/NonRestCallTests.java
index 089bf8464bc7f..3e5b2d73cd74d 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/NonRestCallTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/NonRestCallTests.java
@@ -4,11 +4,13 @@
 package com.azure.search.documents.indexes;
 
 import com.azure.core.credential.AzureKeyCredential;
+import com.azure.core.test.http.MockHttpResponse;
 import org.junit.jupiter.api.parallel.Execution;
 import org.junit.jupiter.api.parallel.ExecutionMode;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 import org.reactivestreams.Publisher;
+import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
 import java.util.stream.Stream;
@@ -26,6 +28,7 @@ public void apiCallReturnsError(Publisher<?> apiCall) {
 
     static Stream<Publisher<?>> apiCallReturnsErrorSupplier() {
         SearchIndexerAsyncClient client = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint("https://fake.com")
             .credential(new AzureKeyCredential("fake"))
             .buildAsyncClient();
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexClientBuilderTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexClientBuilderTests.java
index b3c0cfc16f6eb..940261c6761c1 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexClientBuilderTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexClientBuilderTests.java
@@ -5,6 +5,7 @@
 import com.azure.core.credential.AzureKeyCredential;
 import com.azure.core.exception.HttpResponseException;
 import com.azure.core.http.HttpClient;
+import com.azure.core.http.HttpHeaderName;
 import com.azure.core.http.HttpHeaders;
 import com.azure.core.http.HttpMethod;
 import com.azure.core.http.HttpRequest;
@@ -49,6 +50,7 @@ public class SearchIndexClientBuilderTests {
     @Test
     public void buildSyncClientTest() {
         SearchIndexClient client = new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
@@ -61,6 +63,7 @@ public void buildSyncClientTest() {
     @Test
     public void buildSyncClientUsingDefaultApiVersionTest() {
         SearchIndexClient client = new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .buildClient();
@@ -72,6 +75,7 @@ public void buildSyncClientUsingDefaultApiVersionTest() {
     @Test
     public void buildAsyncClientTest() {
         SearchIndexAsyncClient client = new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
@@ -84,6 +88,7 @@ public void buildAsyncClientTest() {
     @Test
     public void buildAsyncClientUsingDefaultApiVersionTest() {
         SearchIndexAsyncClient client = new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .buildAsyncClient();
@@ -95,6 +100,7 @@ public void buildAsyncClientUsingDefaultApiVersionTest() {
     @Test
     public void whenBuildClientAndVerifyPropertiesThenSuccess() {
         SearchIndexClient client = new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .buildClient();
@@ -102,6 +108,7 @@ public void whenBuildClientAndVerifyPropertiesThenSuccess() {
         assertEquals(searchEndpoint, client.getEndpoint());
 
         SearchIndexAsyncClient asyncClient = new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
@@ -141,7 +148,7 @@ public void serviceClientFreshDateOnRetry() throws MalformedURLException {
 
     public static HttpRequest request(String url) throws MalformedURLException {
         return new HttpRequest(HttpMethod.HEAD,
-            new URL(url), new HttpHeaders().set("Content-Length", "0"),
+            new URL(url), new HttpHeaders().set(HttpHeaderName.CONTENT_LENGTH, "0"),
             Flux.empty());
     }
 
@@ -151,11 +158,11 @@ public static final class FreshDateTestClient implements HttpClient {
         @Override
         public Mono<HttpResponse> send(HttpRequest request) {
             if (firstDate == null) {
-                firstDate = convertToDateObject(request.getHeaders().getValue("Date"));
+                firstDate = convertToDateObject(request.getHeaders().getValue(HttpHeaderName.DATE));
                 return Mono.error(new IOException("IOException!"));
             }
 
-            assert !firstDate.equals(convertToDateObject(request.getHeaders().getValue("Date")));
+            assert !firstDate.equals(convertToDateObject(request.getHeaders().getValue(HttpHeaderName.DATE)));
             return Mono.just(new MockHttpResponse(request, 200));
         }
 
@@ -195,7 +202,7 @@ public void applicationIdFallsBackToLogOptions() {
             .httpLogOptions(new HttpLogOptions().setApplicationId("anOldApplication"))
             .retryPolicy(new RetryPolicy(new FixedDelay(3, Duration.ofMillis(1))))
             .httpClient(httpRequest -> {
-                assertTrue(httpRequest.getHeaders().getValue("User-Agent").contains("anOldApplication"));
+                assertTrue(httpRequest.getHeaders().getValue(HttpHeaderName.USER_AGENT).contains("anOldApplication"));
                 return Mono.just(new MockHttpResponse(httpRequest, 400));
             })
             .buildClient();
@@ -212,7 +219,7 @@ public void clientOptionHeadersAreAddedLast() {
                 .setHeaders(Collections.singletonList(new Header("User-Agent", "custom"))))
             .retryPolicy(new RetryPolicy(new FixedDelay(3, Duration.ofMillis(1))))
             .httpClient(httpRequest -> {
-                assertEquals("custom", httpRequest.getHeaders().getValue("User-Agent"));
+                assertEquals("custom", httpRequest.getHeaders().getValue(HttpHeaderName.USER_AGENT));
                 return Mono.just(new MockHttpResponse(httpRequest, 400));
             })
             .buildClient();
@@ -223,6 +230,7 @@ public void clientOptionHeadersAreAddedLast() {
     @Test
     public void bothRetryOptionsAndRetryPolicySet() {
         assertThrows(IllegalStateException.class, () -> new SearchIndexClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
diff --git a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexerClientBuilderTests.java b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexerClientBuilderTests.java
index 1552fbe5e00ba..722ca13d5d6f9 100644
--- a/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexerClientBuilderTests.java
+++ b/sdk/search/azure-search-documents/src/test/java/com/azure/search/documents/indexes/SearchIndexerClientBuilderTests.java
@@ -5,6 +5,7 @@
 import com.azure.core.credential.AzureKeyCredential;
 import com.azure.core.exception.HttpResponseException;
 import com.azure.core.http.HttpClient;
+import com.azure.core.http.HttpHeaderName;
 import com.azure.core.http.HttpHeaders;
 import com.azure.core.http.HttpMethod;
 import com.azure.core.http.HttpRequest;
@@ -49,6 +50,7 @@ public class SearchIndexerClientBuilderTests {
     @Test
     public void buildSyncClientTest() {
         SearchIndexerClient client = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
@@ -61,6 +63,7 @@ public void buildSyncClientTest() {
     @Test
     public void buildSyncClientUsingDefaultApiVersionTest() {
         SearchIndexerClient client = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .buildClient();
@@ -72,6 +75,7 @@ public void buildSyncClientUsingDefaultApiVersionTest() {
     @Test
     public void buildAsyncClientTest() {
         SearchIndexerAsyncClient client = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
@@ -84,6 +88,7 @@ public void buildAsyncClientTest() {
     @Test
     public void buildAsyncClientUsingDefaultApiVersionTest() {
         SearchIndexerAsyncClient client = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .buildAsyncClient();
@@ -95,6 +100,7 @@ public void buildAsyncClientUsingDefaultApiVersionTest() {
     @Test
     public void whenBuildClientAndVerifyPropertiesThenSuccess() {
         SearchIndexerClient client = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .buildClient();
@@ -102,6 +108,7 @@ public void whenBuildClientAndVerifyPropertiesThenSuccess() {
         assertEquals(searchEndpoint, client.getEndpoint());
 
         SearchIndexerAsyncClient asyncClient = new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)
@@ -141,7 +148,7 @@ public void serviceClientFreshDateOnRetry() throws MalformedURLException {
 
     static HttpRequest request(String url) throws MalformedURLException {
         return new HttpRequest(HttpMethod.HEAD,
-            new URL(url), new HttpHeaders().set("Content-Length", "0"),
+            new URL(url), new HttpHeaders().set(HttpHeaderName.CONTENT_LENGTH, "0"),
             Flux.empty());
     }
 
@@ -151,11 +158,11 @@ static final class FreshDateTestClient implements HttpClient {
         @Override
         public Mono<HttpResponse> send(HttpRequest request) {
             if (firstDate == null) {
-                firstDate = convertToDateObject(request.getHeaders().getValue("Date"));
+                firstDate = convertToDateObject(request.getHeaders().getValue(HttpHeaderName.DATE));
                 return Mono.error(new IOException("IOException!"));
             }
 
-            assert !firstDate.equals(convertToDateObject(request.getHeaders().getValue("Date")));
+            assert !firstDate.equals(convertToDateObject(request.getHeaders().getValue(HttpHeaderName.DATE)));
             return Mono.just(new MockHttpResponse(request, 200));
         }
 
@@ -178,7 +185,7 @@ public void clientOptionsIsPreferredOverLogOptions() {
             .clientOptions(new ClientOptions().setApplicationId("aNewApplication"))
             .retryPolicy(new RetryPolicy(new FixedDelay(3, Duration.ofMillis(1))))
             .httpClient(httpRequest -> {
-                assertTrue(httpRequest.getHeaders().getValue("User-Agent").contains("aNewApplication"));
+                assertTrue(httpRequest.getHeaders().getValue(HttpHeaderName.USER_AGENT).contains("aNewApplication"));
                 return Mono.just(new MockHttpResponse(httpRequest, 400));
             })
             .buildClient();
@@ -195,7 +202,7 @@ public void applicationIdFallsBackToLogOptions() {
             .httpLogOptions(new HttpLogOptions().setApplicationId("anOldApplication"))
             .retryPolicy(new RetryPolicy(new FixedDelay(3, Duration.ofMillis(1))))
             .httpClient(httpRequest -> {
-                assertTrue(httpRequest.getHeaders().getValue("User-Agent").contains("anOldApplication"));
+                assertTrue(httpRequest.getHeaders().getValue(HttpHeaderName.USER_AGENT).contains("anOldApplication"));
                 return Mono.just(new MockHttpResponse(httpRequest, 400));
             })
             .buildClient();
@@ -212,7 +219,7 @@ public void clientOptionHeadersAreAddedLast() {
                 .setHeaders(Collections.singletonList(new Header("User-Agent", "custom"))))
             .retryPolicy(new RetryPolicy(new FixedDelay(3, Duration.ofMillis(1))))
             .httpClient(httpRequest -> {
-                assertEquals("custom", httpRequest.getHeaders().getValue("User-Agent"));
+                assertEquals("custom", httpRequest.getHeaders().getValue(HttpHeaderName.USER_AGENT));
                 return Mono.just(new MockHttpResponse(httpRequest, 400));
             })
             .buildClient();
@@ -223,6 +230,7 @@ public void clientOptionHeadersAreAddedLast() {
     @Test
     public void bothRetryOptionsAndRetryPolicySet() {
         assertThrows(IllegalStateException.class, () -> new SearchIndexerClientBuilder()
+            .httpClient(request -> Mono.just(new MockHttpResponse(request, 200)))
             .endpoint(searchEndpoint)
             .credential(searchApiKeyCredential)
             .serviceVersion(apiVersion)