Add first integration tests for merge detection

scm-it/pom.xml

@@ -192,6 +192,7 @@
             <version>2.10</version>
             <configuration>
               <artifactItems>
+                <!-- Copy war file -->
                 <artifactItem>
                   <groupId>sonia.scm</groupId>
                   <artifactId>scm-webapp</artifactId>
@@ -200,6 +201,15 @@
                   <outputDirectory>${project.build.outputDirectory}</outputDirectory>
                   <destFileName>scm-webapp.war</destFileName>
                 </artifactItem>
+                <!-- Copy integration test plugin -->
+                <artifactItem>
+                  <groupId>sonia.scm.plugins</groupId>
+                  <artifactId>scm-integration-test-plugin</artifactId>
+                  <version>${project.version}</version>
+                  <type>smp</type>
+                  <outputDirectory>${scm.home}/plugins</outputDirectory>
+                  <destFileName>scm-integration-test-plugin.smp</destFileName>
+                </artifactItem>
               </artifactItems>
             </configuration>
             <executions>

scm-it/src/test/java/sonia/scm/it/MergeDetectionITCase.java

@@ -0,0 +1,176 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.it;
+
+import io.restassured.RestAssured;
+import org.assertj.core.api.Assertions;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import sonia.scm.it.utils.RepositoryUtil;
+import sonia.scm.it.utils.RestUtil;
+import sonia.scm.it.utils.TestData;
+import sonia.scm.repository.Person;
+import sonia.scm.repository.client.api.RepositoryClient;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static java.lang.String.format;
+import static java.util.Collections.singletonList;
+import static sonia.scm.it.utils.TestData.USER_SCM_ADMIN;
+
+public class MergeDetectionITCase {
+
+  private static final Person ARTHUR = new Person("arthur", "arthur@hitchhiker.com");
+
+  @Rule
+  public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  RepositoryClient client;
+  String masterFile;
+  String developFile;
+
+  @Before
+  public void createRepository() throws IOException {
+    TestData.createDefault();
+
+    client = RepositoryUtil.createRepositoryClient("git", temporaryFolder.getRoot());
+
+    masterFile = createFile("hg2g.md");
+    developFile = createFile("how_to_make_tea.md");
+
+    client.getAddCommand().add(masterFile);
+    client.getCommitCommand().commit(ARTHUR, "Add base file");
+    client.getPushCommand().push();
+
+    client.getBranchCommand().branch("develop");
+    client.getCheckoutCommand().checkout("develop");
+    client.getAddCommand().add(developFile);
+    client.getCommitCommand().commit(ARTHUR, "add more important things");
+    client.getPushCommand().push();
+  }
+
+  @After
+  public void disableMergeDetection() {
+    RestAssured.given()
+      .auth().preemptive().basic(USER_SCM_ADMIN, USER_SCM_ADMIN)
+      .when()
+      .contentType("application/json")
+      .accept("application/json")
+      .body(toJson("{}"))
+      .post(RestUtil.createResourceUrl("integration-test/merge-detection/"))
+      .then()
+      .statusCode(204);
+  }
+
+  @Test
+  public void shouldDetectSimpleMergeAsMerged() throws IOException {
+    client.getCheckoutCommand().checkout("master");
+    client.getMergeCommand().merge("develop");
+
+    initializeMergeDetection("master", "develop");
+
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isTrue();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isTrue();
+  }
+
+  @Test
+  public void shouldDetectMergeWhenBranchHasBeenDeletedAsMerged() throws IOException {
+    client.getCheckoutCommand().checkout("master");
+    client.getMergeCommand().merge("develop");
+    client.getPushCommand().push();
+
+    initializeMergeDetection("master", "develop");
+
+    client.getDeleteRemoteBranchCommand().delete("develop");
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isTrue();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isTrue();
+  }
+
+  @Test
+  public void shouldDetectNormalPushAsNotMerged() throws IOException {
+    client.getCheckoutCommand().checkout("develop");
+    writeFile(developFile, "other content");
+    client.getAddCommand().add(developFile);
+    client.getCommitCommand().commit(ARTHUR, "simple commit");
+
+    initializeMergeDetection("master", "develop");
+
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isFalse();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isFalse();
+  }
+
+  private boolean getMergeDetectionResult(String type, int n) {
+    return RestAssured.given()
+      .auth().preemptive().basic(USER_SCM_ADMIN, USER_SCM_ADMIN)
+      .when()
+      .accept("application/json")
+      .get(RestUtil.createResourceUrl("integration-test/"))
+      .then()
+      .statusCode(200)
+      .extract()
+      .jsonPath()
+      .getBoolean("_embedded." +
+        type +
+        "[" + n + "].merged");
+  }
+
+  private void initializeMergeDetection(String target, String branch) {
+    RestAssured.given()
+      .auth().preemptive().basic(USER_SCM_ADMIN, USER_SCM_ADMIN)
+      .when()
+      .contentType("application/json")
+      .accept("application/json")
+      .body(toJson(format("{'target': '%s', 'branch': '%s'}", target, branch)))
+      .post(RestUtil.createResourceUrl("integration-test/merge-detection/"))
+      .then()
+      .statusCode(204);
+  }
+
+  private String createFile(String name) throws IOException {
+    temporaryFolder.newFile(name);
+    writeFile(name, "Some content");
+    return name;
+  }
+
+  private void writeFile(String name, String content) throws IOException {
+    Path file = temporaryFolder.getRoot().toPath().resolve(name);
+    Files.write(file, singletonList(content));
+  }
+
+  private String toJson(String json) {
+    return json.replaceAll("'", "\"");
+  }
+}

scm-plugins/pom.xml

@@ -45,6 +45,7 @@
     <module>scm-git-plugin</module>
     <module>scm-svn-plugin</module>
     <module>scm-legacy-plugin</module>
+    <module>scm-integration-test-plugin</module>
   </modules>
 
   <dependencies>

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitCheckoutCommand.java

@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import sonia.scm.repository.client.api.RepositoryClientException;
+
+import java.io.IOException;
+
+public class GitCheckoutCommand implements CheckoutCommand {
+
+  private Git git;
+
+  GitCheckoutCommand(Git git) {
+    this.git = git;
+  }
+
+  @Override
+  public void checkout(String name) throws IOException {
+    try {
+      git.checkout().setName(name).call();
+    } catch (GitAPIException ex) {
+      throw new RepositoryClientException("could not checkout branch or revision", ex);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitDeleteRemoteBranchCommand.java

@@ -0,0 +1,64 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.PushCommand;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.transport.CredentialsProvider;
+import org.eclipse.jgit.transport.RefSpec;
+import sonia.scm.repository.client.api.RepositoryClientException;
+
+import java.io.IOException;
+
+public class GitDeleteRemoteBranchCommand implements DeleteRemoteBranchCommand {
+
+  private final Git git;
+  private final CredentialsProvider credentialsProvider;
+
+  GitDeleteRemoteBranchCommand(Git git, CredentialsProvider credentialsProvider) {
+    this.git = git;
+    this.credentialsProvider = credentialsProvider;
+  }
+
+  @Override
+  public void delete(String name) throws IOException {
+    try {
+      git.branchDelete().setBranchNames("refs/heads/" + name).call();
+      RefSpec refSpec = new RefSpec()
+        .setSource(null)
+        .setDestination("refs/heads/" + name);
+      PushCommand push = git.push();
+      if (credentialsProvider != null) {
+        push.setCredentialsProvider(credentialsProvider);
+      }
+      push.setRefSpecs(refSpec).call();
+
+//      List<String> result = git.branchDelete().setBranchNames(name).call();
+    } catch (GitAPIException ex) {
+      throw new RepositoryClientException("could not delete branch", ex);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitMergeCommand.java

@@ -0,0 +1,64 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.MergeResult;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import sonia.scm.repository.Changeset;
+import sonia.scm.repository.GitChangesetConverter;
+import sonia.scm.repository.client.api.RepositoryClientException;
+
+import java.io.IOException;
+
+public class GitMergeCommand implements MergeCommand {
+
+  private final Git git;
+
+  GitMergeCommand(Git git) {
+    this.git = git;
+  }
+
+  @Override
+  public Changeset merge(MergeRequest request) throws IOException {
+    try (GitChangesetConverter converter = new GitChangesetConverter(git.getRepository())) {
+      ObjectId resolved = git.getRepository().resolve(request.getBranch());
+      MergeResult mergeResult = git.merge()
+        .include(request.getBranch(), resolved)
+        .setMessage(request.getMessage())
+        .call();
+
+      try (RevWalk revWalk = new RevWalk(git.getRepository())) {
+        RevCommit commit = revWalk.parseCommit(mergeResult.getNewHead());
+        return converter.createChangeset(commit);
+      }
+    } catch (GitAPIException ex) {
+      throw new RepositoryClientException("could not commit changes to repository", ex);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitRepositoryClientProvider.java

@@ -49,7 +49,7 @@ public class GitRepositoryClientProvider extends RepositoryClientProvider
   private static final Set<ClientCommand> SUPPORTED_COMMANDS =
     ImmutableSet.of(ClientCommand.ADD, ClientCommand.REMOVE,
       ClientCommand.COMMIT, ClientCommand.TAG, ClientCommand.BRANCH,
-      ClientCommand.PUSH);
+      ClientCommand.DELETE_REMOTE_BRANCH, ClientCommand.MERGE, ClientCommand.PUSH);
 
   //~--- constructors ---------------------------------------------------------
 
@@ -118,6 +118,16 @@ public class GitRepositoryClientProvider extends RepositoryClientProvider
     return new GitBranchCommand(git);
   }
 
+  @Override
+  public DeleteRemoteBranchCommand getDeleteRemoteBranchCommand() {
+    return new GitDeleteRemoteBranchCommand(git, credentialsProvider);
+  }
+
+  @Override
+  public CheckoutCommand getCheckoutCommand() {
+    return new GitCheckoutCommand(git);
+  }
+
   /**
    * Method description
    *
@@ -178,6 +188,11 @@ public class GitRepositoryClientProvider extends RepositoryClientProvider
     return new GitTagCommand(git);
   }
 
+  @Override
+  public MergeCommand getMergeCommand() {
+    return new GitMergeCommand(git);
+  }
+
   @Override
   public File getWorkingCopy() {
     return git.getRepository().getWorkTree();

scm-plugins/scm-integration-test-plugin/pom.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    MIT License
+
+    Copyright (c) 2020-present Cloudogu GmbH and Contributors
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>sonia.scm.plugins</groupId>
+    <artifactId>scm-plugins</artifactId>
+    <version>2.4.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>scm-integration-test-plugin</artifactId>
+  <description>Add functions for integration tests. This is not intended for production systems.</description>
+  <version>2.4.0-SNAPSHOT</version>
+  <packaging>smp</packaging>
+
+  <dependencies>
+
+    <!-- servlet api -->
+
+    <dependency>
+      <groupId>javax.servlet</groupId>
+      <artifactId>javax.servlet-api</artifactId>
+      <version>${servlet.version}</version>
+      <scope>provided</scope>
+    </dependency>
+
+  </dependencies>
+</project>

scm-plugins/scm-integration-test-plugin/src/main/java/sonia/scm/it/resource/IntegrationTestResource.java

@@ -0,0 +1,113 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.it.resource;
+
+import de.otto.edison.hal.Embedded;
+import de.otto.edison.hal.HalRepresentation;
+import de.otto.edison.hal.Links;
+import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.Getter;
+import lombok.Setter;
+import sonia.scm.api.v2.resources.LinkBuilder;
+import sonia.scm.api.v2.resources.ScmPathInfoStore;
+import sonia.scm.plugin.Extension;
+
+import javax.inject.Inject;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+
+import static de.otto.edison.hal.Embedded.embeddedBuilder;
+import static de.otto.edison.hal.Links.linkingTo;
+
+/**
+ * Web Service Resource to support integration tests.
+ */
+@OpenAPIDefinition(tags = {
+  @Tag(name = "Integration Test", description = "Support for integration tests")
+})
+@Path(IntegrationTestResource.INTEGRATION_TEST_PATH_V2)
+@Extension
+public class IntegrationTestResource {
+
+  static final String INTEGRATION_TEST_PATH_V2 = "v2/integration-test";
+
+  private final ScmPathInfoStore scmPathInfoStore;
+  private final MergeDetectionHelper mergeDetectionHelper;
+
+  @Inject
+  public IntegrationTestResource(ScmPathInfoStore scmPathInfoStore, MergeDetectionHelper mergeDetectionHelper) {
+    this.scmPathInfoStore = scmPathInfoStore;
+    this.mergeDetectionHelper = mergeDetectionHelper;
+  }
+
+  @GET
+  @Path("")
+  @Produces("application/json")
+  public CollectionDto get() {
+    Links links = linkingTo()
+      .self(self())
+      .build();
+    Embedded embedded = embeddedBuilder()
+      .with("preMergeDetection", mergeDetectionHelper.getPreMergeDetections())
+      .with("postMergeDetection", mergeDetectionHelper.getPostMergeDetections())
+      .build();
+    return new CollectionDto(links, embedded);
+  }
+
+  @POST
+  @Path("merge-detection")
+  @Consumes("application/json")
+  public void initMergeDetection(MergeDetectionConfigurationDto mergeDetectionConfiguration) {
+    mergeDetectionHelper.initialize(mergeDetectionConfiguration.getTarget(), mergeDetectionConfiguration.getBranch());
+  }
+
+  private String self() {
+    LinkBuilder linkBuilder = new LinkBuilder(scmPathInfoStore.get(), IntegrationTestResource.class);
+    return linkBuilder.method("get").parameters().href();
+  }
+
+  static class CollectionDto extends HalRepresentation {
+
+    CollectionDto(Links links, Embedded embedded) {
+      super(links, embedded);
+    }
+
+    @Override
+    protected HalRepresentation withEmbedded(String rel, HalRepresentation embeddedItem) {
+      return super.withEmbedded(rel, embeddedItem);
+    }
+  }
+
+  @Getter
+  @Setter
+  static class MergeDetectionConfigurationDto {
+    private String target;
+    private String branch;
+  }
+}

scm-plugins/scm-integration-test-plugin/src/main/java/sonia/scm/it/resource/MergeDetectionHelper.java

@@ -0,0 +1,101 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.it.resource;
+
+import com.github.legman.Subscribe;
+import de.otto.edison.hal.HalRepresentation;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import sonia.scm.EagerSingleton;
+import sonia.scm.plugin.Extension;
+import sonia.scm.repository.PostReceiveRepositoryHookEvent;
+import sonia.scm.repository.PreReceiveRepositoryHookEvent;
+import sonia.scm.repository.RepositoryHookEvent;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@EagerSingleton
+@Extension
+public class MergeDetectionHelper {
+
+  private final List<ResultDto> preMergeDetections = new ArrayList<>();
+  private final List<ResultDto> postMergeDetections = new ArrayList<>();
+
+  private String target;
+  private String branch;
+
+  @Subscribe
+  public void handlePreReceiveEvent(PreReceiveRepositoryHookEvent event) {
+    if (target == null || branch == null) {
+      return;
+    }
+    preMergeDetections.add(createDto(event));
+  }
+
+  @Subscribe
+  public void handlePostReceiveEvent(PostReceiveRepositoryHookEvent event) {
+    if (target == null || branch == null) {
+      return;
+    }
+    postMergeDetections.add(createDto(event));
+  }
+
+  public ResultDto createDto(RepositoryHookEvent event) {
+    HookMergeDetectionProvider mergeDetectionProvider = event.getContext().getMergeDetectionProvider();
+    boolean merged = mergeDetectionProvider.branchesMerged(target, branch);
+    return new ResultDto(
+      event.getClass().getSimpleName(),
+      event.getRepository().getNamespace(),
+      event.getRepository().getName(),
+      merged
+    );
+  }
+
+  void initialize(String target, String branch) {
+    this.target = target;
+    this.branch = branch;
+    preMergeDetections.clear();
+    postMergeDetections.clear();
+  }
+
+  public List<ResultDto> getPreMergeDetections() {
+    return preMergeDetections;
+  }
+
+  public List<ResultDto> getPostMergeDetections() {
+    return postMergeDetections;
+  }
+
+  @Getter
+  @AllArgsConstructor
+  static class ResultDto extends HalRepresentation {
+    private String type;
+    private String namespace;
+    private String name;
+    private boolean merged;
+  }
+}

scm-plugins/scm-integration-test-plugin/src/main/resources/META-INF/scm/plugin.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!--
+
+    MIT License
+
+    Copyright (c) 2020-present Cloudogu GmbH and Contributors
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+-->
+<!DOCTYPE plugin SYSTEM "https://download.scm-manager.org/dtd/plugin/2.0.0-01.dtd">
+<plugin>
+
+  <scm-version>2</scm-version>
+
+  <information>
+    <displayName>Integration Test Support</displayName>
+    <author>Cloudogu GmbH</author>
+    <category>Test</category>
+  </information>
+
+  <conditions>
+    <min-version>${project.parent.version}</min-version>
+  </conditions>
+
+</plugin>

scm-test/src/main/java/sonia/scm/repository/client/api/CheckoutCommandBuilder.java

@@ -0,0 +1,53 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.api;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.repository.client.spi.CheckoutCommand;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public final class CheckoutCommandBuilder {
+
+  private static final Logger LOG = LoggerFactory.getLogger(CheckoutCommandBuilder.class);
+
+  private final CheckoutCommand command;
+
+  public CheckoutCommandBuilder(CheckoutCommand command) {
+    this.command = command;
+  }
+
+  public CheckoutCommandBuilder checkout(String name) throws IOException {
+    LOG.debug("checkout {}", name);
+
+    command.checkout(name);
+
+    return this;
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/api/ClientCommand.java

@@ -31,5 +31,5 @@ package sonia.scm.repository.client.api;
  */
 public enum ClientCommand
 {
-  ADD, REMOVE, COMMIT, PUSH, TAG, BRANCH
+  ADD, REMOVE, COMMIT, PUSH, TAG, BRANCH, DELETE_REMOTE_BRANCH, CHECKOUT, MERGE
 }

scm-test/src/main/java/sonia/scm/repository/client/api/DeleteRemoteBranchCommandBuilder.java

@@ -0,0 +1,53 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.api;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.repository.client.spi.DeleteRemoteBranchCommand;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public final class DeleteRemoteBranchCommandBuilder {
+
+  private static final Logger LOG = LoggerFactory.getLogger(DeleteRemoteBranchCommandBuilder.class);
+
+  private DeleteRemoteBranchCommand command;
+
+  public DeleteRemoteBranchCommandBuilder(DeleteRemoteBranchCommand command) {
+    this.command = command;
+  }
+
+  public DeleteRemoteBranchCommandBuilder delete(String name) throws IOException {
+    LOG.debug("delete branch {}", name);
+
+    command.delete(name);
+
+    return this;
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/api/MergeCommandBuilder.java

@@ -0,0 +1,48 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.api;
+
+import sonia.scm.repository.client.spi.MergeCommand;
+import sonia.scm.repository.client.spi.MergeRequest;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public final class MergeCommandBuilder {
+
+  private final MergeCommand command;
+
+  MergeCommandBuilder(MergeCommand command) {
+    this.command = command;
+  }
+
+  public void merge(String branch) throws IOException {
+    MergeRequest request = new MergeRequest();
+    request.setBranch(branch);
+    command.merge(request);
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/api/RepositoryClient.java

@@ -60,6 +60,18 @@ public final class RepositoryClient implements Closeable {
     return new BranchCommandBuilder(clientProvider.getBranchCommand());
   }
 
+  public DeleteRemoteBranchCommandBuilder getDeleteRemoteBranchCommand() {
+    logger.trace("delete branch command");
+
+    return new DeleteRemoteBranchCommandBuilder(clientProvider.getDeleteRemoteBranchCommand());
+  }
+
+  public CheckoutCommandBuilder getCheckoutCommand() {
+    logger.trace("create checkout command");
+
+    return new CheckoutCommandBuilder(clientProvider.getCheckoutCommand());
+  }
+
   public CommitCommandBuilder getCommitCommand() {
     logger.trace("create commit command");
 
@@ -84,6 +96,12 @@ public final class RepositoryClient implements Closeable {
     return new TagCommandBuilder(clientProvider.getTagCommand());
   }
 
+  public MergeCommandBuilder getMergeCommand() {
+    logger.trace("create merge command");
+
+    return new MergeCommandBuilder(clientProvider.getMergeCommand());
+  }
+
   public File getWorkingCopy() {
     return clientProvider.getWorkingCopy();
   }

scm-test/src/main/java/sonia/scm/repository/client/spi/CheckoutCommand.java

@@ -0,0 +1,35 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public interface CheckoutCommand {
+
+  void checkout(String name) throws IOException;
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/DeleteRemoteBranchCommand.java

@@ -0,0 +1,32 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import java.io.IOException;
+
+public interface DeleteRemoteBranchCommand {
+
+  void delete(String name) throws IOException;
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/MergeCommand.java

@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import sonia.scm.repository.Changeset;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public interface MergeCommand {
+
+  Changeset merge(MergeRequest request) throws IOException;
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/MergeRequest.java

@@ -0,0 +1,89 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.base.Objects;
+
+/**
+ * @since 2.4.0
+ */
+public final class MergeRequest {
+
+  private String branch;
+  private String message;
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj == null)
+    {
+      return false;
+    }
+
+    if (getClass() != obj.getClass())
+    {
+      return false;
+    }
+
+    final MergeRequest other = (MergeRequest) obj;
+
+    return Objects.equal(branch, other.branch)
+      && Objects.equal(message, other.message);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hashCode(branch, message);
+  }
+
+  public void reset() {
+    this.branch = null;
+    this.message = null;
+  }
+
+  @Override
+  public String toString() {
+    return MoreObjects.toStringHelper(this)
+                  .add("branch", branch)
+                  .add("message", message)
+                  .toString();
+  }
+
+  public void setBranch(String branch) {
+    this.branch = branch;
+  }
+
+  public void setMessage(String message) {
+    this.message = message;
+  }
+
+  String getBranch() {
+    return branch;
+  }
+
+  String getMessage() {
+    return message;
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/RepositoryClientProvider.java

@@ -87,6 +87,14 @@ public abstract class RepositoryClientProvider implements Closeable
     throw new ClientCommandNotSupportedException(ClientCommand.BRANCH);
   }
 
+  public DeleteRemoteBranchCommand getDeleteRemoteBranchCommand() {
+    throw new ClientCommandNotSupportedException(ClientCommand.DELETE_REMOTE_BRANCH);
+  }
+
+  public CheckoutCommand getCheckoutCommand() {
+    throw new ClientCommandNotSupportedException(ClientCommand.CHECKOUT);
+  }
+
   /**
    * Method description
    *
@@ -131,6 +139,10 @@ public abstract class RepositoryClientProvider implements Closeable
     throw new ClientCommandNotSupportedException(ClientCommand.TAG);
   }
 
+  public MergeCommand getMergeCommand() {
+    throw new ClientCommandNotSupportedException(ClientCommand.MERGE);
+  }
+
   /**
    * Returns the working copy of the repository client.
    *