Add design & unit test

doc/design.md

@@ -166,6 +166,20 @@ Covers:
 
 Needs: impl, itest
 
+#### Excluding Implicit Plugins from Dependencies.md
+
+`dsn~dependency.md-file-validator-excludes-implicit-plugins~1`
+
+PK excludes implicit plugins from `dependencies.md`.
+
+Background:
+
+Maven implicitly adds plugins like `org.apache.maven.plugins:maven-clean-plugin` due to the Maven lifecycle. The version of these plugins depends on the Maven version. Each plugin version defines its own name and license which is included in `dependencies.md`. That means the content of `dependencies.md` depends on the Maven version, causing build failures when using a different Maven version, see [issue #436](https://github.com/exasol/project-keeper/issues/436).
+
+One workaround is pinning the Maven version using `maven-enforcer-plugin` but this causes problems on developer's machines. That's why we decided to remove these implicit plugins from `dependencies.md`.
+
+Needs: impl, utest, itest
+
 ### Readme.md File Validator
 
 `dsn~readme-validator~1`

maven-project-crawler/pom.xml

@@ -80,6 +80,11 @@
             <artifactId>mockito-core</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>com.exasol</groupId>
             <artifactId>maven-plugin-integration-testing</artifactId>

maven-project-crawler/src/main/java/com/exasol/projectkeeper/validators/dependencies/ProjectDependencyReader.java

@@ -42,7 +42,8 @@ public ProjectDependencyReader(final MavenModelFromRepositoryReader artifactMode
      */
     public ProjectDependencies readDependencies() {
         final List<ProjectDependency> dependencies = getDependenciesIncludingPlugins()
-                .map(dependency -> getLicense(dependency, project)).collect(Collectors.toList());
+                .map(dependency -> getLicense(dependency, project)) //
+                .collect(Collectors.toList());
         return new ProjectDependencies(dependencies);
     }
 
@@ -86,6 +87,7 @@ private Stream<Dependency> getPluginDependencies() {
      * @param plugin the plugin to check
      * @return {@code true} if the plugin is explicitly added to the build
      */
+    // [impl -> dsn~dependency.md-file-validator-excludes-implicit-plugins~1]
     private boolean isExplicitPlugin(final Plugin plugin) {
         final String location = plugin.getLocation("").getSource().getLocation();
         return location != null;

maven-project-crawler/src/test/java/com/exasol/projectkeeper/dependencies/ProjectDependencyReaderTest.java

@@ -0,0 +1,90 @@
+package com.exasol.projectkeeper.dependencies;
+
+import static java.util.Collections.emptyList;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.empty;
+import static org.mockito.ArgumentMatchers.anyList;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.when;
+
+import java.util.List;
+
+import org.apache.maven.model.*;
+import org.apache.maven.project.MavenProject;
+import org.apache.maven.project.ProjectBuildingException;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.exasol.projectkeeper.pom.MavenModelFromRepositoryReader;
+import com.exasol.projectkeeper.shared.dependencies.BaseDependency.Type;
+import com.exasol.projectkeeper.shared.dependencies.License;
+import com.exasol.projectkeeper.shared.dependencies.ProjectDependency;
+import com.exasol.projectkeeper.validators.dependencies.ProjectDependencyReader;
+
+@ExtendWith(MockitoExtension.class)
+class ProjectDependencyReaderTest {
+
+    @Mock
+    MavenModelFromRepositoryReader artifactModelReaderMock;
+
+    private List<ProjectDependency> readDependencies(final List<Plugin> plugins) {
+        final MavenProject project = new MavenProject(new Model());
+        project.getModel().setBuild(new Build());
+        project.getModel().getBuild().setPlugins(plugins);
+        return new ProjectDependencyReader(artifactModelReaderMock, project).readDependencies().getDependencies();
+    }
+
+    @Test
+    void noDependencies() {
+        assertThat(readDependencies(emptyList()), empty());
+    }
+
+    @Test
+    void explicitPlugin() throws ProjectBuildingException {
+        simulateDependencies("group", "art", "ver", "website", List.of(mavenLicense("license", "licenseUrl")));
+
+        assertThat(readDependencies(List.of(plugin("group", "art", "ver", "no-null"))),
+                contains(ProjectDependency.builder().type(Type.PLUGIN).name("name:group:art").websiteUrl("website")
+                        .licenses(List.of(new License("license", "licenseUrl"))).build()));
+    }
+
+    // [utest -> dsn~dependency.md-file-validator-excludes-implicit-plugins~1]
+    @Test
+    void implicitPlugin() throws ProjectBuildingException {
+        assertThat(readDependencies(List.of(plugin("group", "art", "ver", null))), empty());
+    }
+
+    private void simulateDependencies(final String groupId, final String artifactId, final String version,
+            final String url, final List<org.apache.maven.model.License> licenses) throws ProjectBuildingException {
+        final Model model = new Model();
+        model.setArtifactId(artifactId);
+        model.setGroupId(groupId);
+        model.setVersion(version);
+        model.setName("name:" + groupId + ":" + artifactId);
+        model.setUrl(url);
+        model.setLicenses(licenses);
+        when(artifactModelReaderMock.readModel(eq(artifactId), eq(groupId), eq(version), anyList())).thenReturn(model);
+    }
+
+    private org.apache.maven.model.License mavenLicense(final String name, final String url) {
+        final org.apache.maven.model.License license = new org.apache.maven.model.License();
+        license.setName(name);
+        license.setUrl(url);
+        return license;
+    }
+
+    private Plugin plugin(final String groupId, final String artifactId, final String version,
+            final String sourceLocation) {
+        final Plugin plugin = new Plugin();
+        plugin.setGroupId(groupId);
+        plugin.setArtifactId(artifactId);
+        plugin.setVersion(version);
+        final InputSource source = new InputSource();
+        source.setLocation(sourceLocation);
+        plugin.setLocation("", new InputLocation(0, 0, source));
+        return plugin;
+    }
+}

project-keeper/src/test/java/com/exasol/projectkeeper/validators/dependencies/DependenciesValidatorIT.java

@@ -67,6 +67,7 @@ void testWrongContentWithNonDefaultRepository() throws IOException {
         assertThat(output, containsString("E-PK-CORE-53: The dependencies.md file has outdated content."));
     }
 
+    // [itest -> dsn~dependency.md-file-validator-excludes-implicit-plugins~1]
     @Test
     void testFix() throws IOException {
         createExamplePomFile();