Convert RestSession into the interface in tests.

This allows to provide a different implementations in google internal
tests.

Google-Bug-Id: b/289356590
Release-Notes: skip
Change-Id: I5c30c25f0b5a9a6ca08409861b4079e7c8e97478
diff --git a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
index faaafe0..eb48d85 100644
--- a/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
+++ b/java/com/google/gerrit/acceptance/AbstractDaemonTest.java
@@ -603,9 +603,9 @@
     reindexAccount(admin.id());
     reindexAccount(user.id());
 
-    adminRestSession = new RestSession(server, admin);
-    userRestSession = new RestSession(server, user);
-    anonymousRestSession = new RestSession(server, null);
+    adminRestSession = createRestSession(admin);
+    userRestSession = createRestSession(user);
+    anonymousRestSession = createRestSession(null);
 
     initSsh();
 
@@ -624,6 +624,10 @@
     }
   }
 
+  RestSession createRestSession(@Nullable TestAccount account) {
+    return new GerritServerRestSession(server, account);
+  }
+
   protected void initServer(GerritServer.Description classDesc, GerritServer.Description methodDesc)
       throws Exception {
     Module module = createModule();
diff --git a/java/com/google/gerrit/acceptance/GerritServerRestSession.java b/java/com/google/gerrit/acceptance/GerritServerRestSession.java
new file mode 100644
index 0000000..c2c77fe
--- /dev/null
+++ b/java/com/google/gerrit/acceptance/GerritServerRestSession.java
@@ -0,0 +1,148 @@
+// Copyright (C) 2024 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.acceptance;
+
+import static com.google.common.net.HttpHeaders.ACCEPT;
+import static com.google.common.net.HttpHeaders.CONTENT_TYPE;
+import static com.google.gerrit.json.OutputFormat.JSON_COMPACT;
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Objects.requireNonNull;
+
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.extensions.restapi.RawInput;
+import java.io.IOException;
+import org.apache.http.Header;
+import org.apache.http.client.fluent.Request;
+import org.apache.http.entity.BufferedHttpEntity;
+import org.apache.http.entity.InputStreamEntity;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.message.BasicHeader;
+
+/** Sends requests to {@link GerritServer} as a specified user. */
+public class GerritServerRestSession extends HttpSession implements RestSession {
+
+  public GerritServerRestSession(GerritServer server, @Nullable TestAccount account) {
+    super(server, account);
+  }
+
+  @Override
+  public RestResponse get(String endPoint) throws IOException {
+    return getWithHeaders(endPoint);
+  }
+
+  @Override
+  public RestResponse getJsonAccept(String endPoint) throws IOException {
+    return getWithHeaders(endPoint, new BasicHeader(ACCEPT, "application/json"));
+  }
+
+  @Override
+  public RestResponse getWithHeaders(String endPoint, Header... headers) throws IOException {
+    Request get = Request.Get(getUrl(endPoint));
+    if (headers != null) {
+      get.setHeaders(headers);
+    }
+    return execute(get);
+  }
+
+  @Override
+  public RestResponse head(String endPoint) throws IOException {
+    return execute(Request.Head(getUrl(endPoint)));
+  }
+
+  @Override
+  public RestResponse put(String endPoint) throws IOException {
+    return put(endPoint, /* content = */ null);
+  }
+
+  @Override
+  public RestResponse put(String endPoint, Object content) throws IOException {
+    return putWithHeaders(endPoint, content);
+  }
+
+  @Override
+  public RestResponse putWithHeaders(String endPoint, Header... headers) throws IOException {
+    return putWithHeaders(endPoint, /* content= */ null, headers);
+  }
+
+  @Override
+  public RestResponse putWithHeaders(String endPoint, Object content, Header... headers)
+      throws IOException {
+    Request put = Request.Put(getUrl(endPoint));
+    if (headers != null) {
+      put.setHeaders(headers);
+    }
+    if (content != null) {
+      addContentToRequest(put, content);
+    }
+    return execute(put);
+  }
+
+  @Override
+  public RestResponse putRaw(String endPoint, RawInput stream) throws IOException {
+    requireNonNull(stream);
+    Request put = Request.Put(getUrl(endPoint));
+    put.addHeader(new BasicHeader(CONTENT_TYPE, stream.getContentType()));
+    put.body(
+        new BufferedHttpEntity(
+            new InputStreamEntity(stream.getInputStream(), stream.getContentLength())));
+    return execute(put);
+  }
+
+  @Override
+  public RestResponse post(String endPoint) throws IOException {
+    return post(endPoint, /* content = */ null);
+  }
+
+  @Override
+  public RestResponse post(String endPoint, Object content) throws IOException {
+    return postWithHeaders(endPoint, content);
+  }
+
+  @Override
+  public RestResponse postWithHeaders(String endPoint, Object content, Header... headers)
+      throws IOException {
+    Request post = Request.Post(getUrl(endPoint));
+    if (headers != null) {
+      post.setHeaders(headers);
+    }
+    if (content != null) {
+      addContentToRequest(post, content);
+    }
+    return execute(post);
+  }
+
+  private static void addContentToRequest(Request request, Object content) {
+    request.addHeader(new BasicHeader(CONTENT_TYPE, "application/json"));
+    request.body(new StringEntity(JSON_COMPACT.newGson().toJson(content), UTF_8));
+  }
+
+  @Override
+  public RestResponse delete(String endPoint) throws IOException {
+    return execute(Request.Delete(getUrl(endPoint)));
+  }
+
+  @Override
+  public RestResponse deleteWithHeaders(String endPoint, Header... headers) throws IOException {
+    Request delete = Request.Delete(getUrl(endPoint));
+    if (headers != null) {
+      delete.setHeaders(headers);
+    }
+    return execute(delete);
+  }
+
+  private String getUrl(String endPoint) {
+    return url + (account != null ? "/a" : "") + endPoint;
+  }
+}
diff --git a/java/com/google/gerrit/acceptance/HttpSession.java b/java/com/google/gerrit/acceptance/HttpSession.java
index 833c53b..ef14a3d 100644
--- a/java/com/google/gerrit/acceptance/HttpSession.java
+++ b/java/com/google/gerrit/acceptance/HttpSession.java
@@ -25,7 +25,7 @@
 import org.apache.http.impl.client.HttpClientBuilder;
 
 public class HttpSession {
-  protected TestAccount account;
+  protected @Nullable TestAccount account;
   protected final String url;
   private final Executor executor;
 
diff --git a/java/com/google/gerrit/acceptance/RestSession.java b/java/com/google/gerrit/acceptance/RestSession.java
index 342cbd0..fd93dbc 100644
--- a/java/com/google/gerrit/acceptance/RestSession.java
+++ b/java/com/google/gerrit/acceptance/RestSession.java
@@ -11,123 +11,48 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
 package com.google.gerrit.acceptance;
 
-import static com.google.common.net.HttpHeaders.ACCEPT;
-import static com.google.common.net.HttpHeaders.CONTENT_TYPE;
-import static com.google.gerrit.json.OutputFormat.JSON_COMPACT;
-import static java.nio.charset.StandardCharsets.UTF_8;
-import static java.util.Objects.requireNonNull;
-
-import com.google.gerrit.common.Nullable;
+import com.google.gerrit.common.UsedAt;
 import com.google.gerrit.extensions.restapi.RawInput;
 import java.io.IOException;
 import org.apache.http.Header;
 import org.apache.http.client.fluent.Request;
-import org.apache.http.entity.BufferedHttpEntity;
-import org.apache.http.entity.InputStreamEntity;
-import org.apache.http.entity.StringEntity;
-import org.apache.http.message.BasicHeader;
 
-public class RestSession extends HttpSession {
+/** Makes rest requests to gerrit backend. */
+@UsedAt(UsedAt.Project.GOOGLE) // Google has own implementation of this interface in tests.
+public interface RestSession {
+  String url();
 
-  public RestSession(GerritServer server, @Nullable TestAccount account) {
-    super(server, account);
-  }
+  RestResponse execute(Request request) throws IOException;
 
-  public RestResponse get(String endPoint) throws IOException {
-    return getWithHeaders(endPoint);
-  }
+  RestResponse get(String endPoint) throws IOException;
 
-  public RestResponse getJsonAccept(String endPoint) throws IOException {
-    return getWithHeaders(endPoint, new BasicHeader(ACCEPT, "application/json"));
-  }
+  RestResponse getJsonAccept(String endPoint) throws IOException;
 
-  public RestResponse getWithHeaders(String endPoint, Header... headers) throws IOException {
-    Request get = Request.Get(getUrl(endPoint));
-    if (headers != null) {
-      get.setHeaders(headers);
-    }
-    return execute(get);
-  }
+  RestResponse getWithHeaders(String endPoint, Header... headers) throws IOException;
 
-  public RestResponse head(String endPoint) throws IOException {
-    return execute(Request.Head(getUrl(endPoint)));
-  }
+  RestResponse head(String endPoint) throws IOException;
 
-  public RestResponse put(String endPoint) throws IOException {
-    return put(endPoint, /* content = */ null);
-  }
+  RestResponse put(String endPoint) throws IOException;
 
-  public RestResponse put(String endPoint, Object content) throws IOException {
-    return putWithHeaders(endPoint, content);
-  }
+  RestResponse put(String endPoint, Object content) throws IOException;
 
-  public RestResponse putWithHeaders(String endPoint, Header... headers) throws IOException {
-    return putWithHeaders(endPoint, /* content= */ null, headers);
-  }
+  RestResponse putWithHeaders(String endPoint, Header... headers) throws IOException;
 
-  public RestResponse putWithHeaders(String endPoint, Object content, Header... headers)
-      throws IOException {
-    Request put = Request.Put(getUrl(endPoint));
-    if (headers != null) {
-      put.setHeaders(headers);
-    }
-    if (content != null) {
-      addContentToRequest(put, content);
-    }
-    return execute(put);
-  }
+  RestResponse putWithHeaders(String endPoint, Object content, Header... headers)
+      throws IOException;
 
-  public RestResponse putRaw(String endPoint, RawInput stream) throws IOException {
-    requireNonNull(stream);
-    Request put = Request.Put(getUrl(endPoint));
-    put.addHeader(new BasicHeader(CONTENT_TYPE, stream.getContentType()));
-    put.body(
-        new BufferedHttpEntity(
-            new InputStreamEntity(stream.getInputStream(), stream.getContentLength())));
-    return execute(put);
-  }
+  RestResponse putRaw(String endPoint, RawInput stream) throws IOException;
 
-  public RestResponse post(String endPoint) throws IOException {
-    return post(endPoint, /* content = */ null);
-  }
+  RestResponse post(String endPoint) throws IOException;
 
-  public RestResponse post(String endPoint, Object content) throws IOException {
-    return postWithHeaders(endPoint, content);
-  }
+  RestResponse post(String endPoint, Object content) throws IOException;
 
-  public RestResponse postWithHeaders(String endPoint, Object content, Header... headers)
-      throws IOException {
-    Request post = Request.Post(getUrl(endPoint));
-    if (headers != null) {
-      post.setHeaders(headers);
-    }
-    if (content != null) {
-      addContentToRequest(post, content);
-    }
-    return execute(post);
-  }
+  RestResponse postWithHeaders(String endPoint, Object content, Header... headers)
+      throws IOException;
 
-  private static void addContentToRequest(Request request, Object content) {
-    request.addHeader(new BasicHeader(CONTENT_TYPE, "application/json"));
-    request.body(new StringEntity(JSON_COMPACT.newGson().toJson(content), UTF_8));
-  }
+  RestResponse delete(String endPoint) throws IOException;
 
-  public RestResponse delete(String endPoint) throws IOException {
-    return execute(Request.Delete(getUrl(endPoint)));
-  }
-
-  public RestResponse deleteWithHeaders(String endPoint, Header... headers) throws IOException {
-    Request delete = Request.Delete(getUrl(endPoint));
-    if (headers != null) {
-      delete.setHeaders(headers);
-    }
-    return execute(delete);
-  }
-
-  private String getUrl(String endPoint) {
-    return url + (account != null ? "/a" : "") + endPoint;
-  }
+  RestResponse deleteWithHeaders(String endPoint, Header... headers) throws IOException;
 }
diff --git a/javatests/com/google/gerrit/acceptance/rest/account/ImpersonationIT.java b/javatests/com/google/gerrit/acceptance/rest/account/ImpersonationIT.java
index 4477140..2e706b8 100644
--- a/javatests/com/google/gerrit/acceptance/rest/account/ImpersonationIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/account/ImpersonationIT.java
@@ -34,7 +34,6 @@
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.RestResponse;
-import com.google.gerrit.acceptance.RestSession;
 import com.google.gerrit.acceptance.TestAccount;
 import com.google.gerrit.acceptance.UseLocalDisk;
 import com.google.gerrit.acceptance.config.GerritConfig;
@@ -98,13 +97,11 @@
   @Inject private ProjectOperations projectOperations;
   @Inject private RequestScopeOperations requestScopeOperations;
 
-  private RestSession anonRestSession;
   private TestAccount admin2;
   private GroupInfo newGroup;
 
   @Before
   public void setUp() throws Exception {
-    anonRestSession = new RestSession(server, null);
     admin2 = accountCreator.admin2();
     GroupInput gi = new GroupInput();
     gi.name = name("New-Group");
@@ -759,7 +756,7 @@
   @Test
   public void runAsNeverPermittedForAnonymousUsers() throws Exception {
     allowRunAs();
-    RestResponse res = anonRestSession.getWithHeaders("/changes/", runAsHeader(user.id()));
+    RestResponse res = anonymousRestSession.getWithHeaders("/changes/", runAsHeader(user.id()));
     res.assertForbidden();
     assertThat(res.getEntityContent()).isEqualTo("not permitted to use X-Gerrit-RunAs");
   }
diff --git a/javatests/com/google/gerrit/acceptance/rest/auth/AuthenticationCheckIT.java b/javatests/com/google/gerrit/acceptance/rest/auth/AuthenticationCheckIT.java
index 9f0089e..1951bdd 100644
--- a/javatests/com/google/gerrit/acceptance/rest/auth/AuthenticationCheckIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/auth/AuthenticationCheckIT.java
@@ -18,7 +18,6 @@
 
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.RestResponse;
-import com.google.gerrit.acceptance.RestSession;
 import java.io.BufferedReader;
 import java.util.stream.Collectors;
 import org.junit.Test;
@@ -33,8 +32,7 @@
 
   @Test
   public void authCheck_anonymousUser_returnsForbidden() throws Exception {
-    RestSession anonymous = new RestSession(server, null);
-    RestResponse r = anonymous.get("/auth-check");
+    RestResponse r = anonymousRestSession.get("/auth-check");
     r.assertForbidden();
   }