projects.add(project1);
        MavenProject project2 = createProject("groupId", "artifactId2", "1.0");
        projects.add(project2);
        project1.getDependencies().add(createDependency(project2));

        projects = new ProjectSorter(projects).getSortedProjects();

        assertEquals(project2, projects.get(0));
        assertEquals(project1, projects.get(1));
    }

    @Test

            throws DuplicateProjectException {
        Map<String, MavenProject> index = new LinkedHashMap<>();
        Map<String, List<File>> collisions = new LinkedHashMap<>();

        for (MavenProject project : projects) {
            String projectId = ArtifactUtils.key(project.getGroupId(), project.getArtifactId(), project.getVersion());

    public void setProjects(List<MavenProject> projects) {
        if (!projects.isEmpty()) {
            MavenProject first = projects.get(0);
            this.currentProject = ThreadLocal.withInitial(() -> first);
            this.topLevelProject = projects.stream()
                    .filter(project -> project.isExecutionRoot())
                    .findFirst()
                    .orElse(first);

import org.apache.maven.project.CycleDetectedException;
import org.apache.maven.project.DuplicateProjectException;
import org.apache.maven.project.MavenProject;
import org.apache.maven.project.ProjectBuildingException;
import org.apache.maven.project.collector.MultiModuleCollectionStrategy;
import org.apache.maven.project.collector.PomlessCollectionStrategy;
import org.apache.maven.project.collector.RequestPomCollectionStrategy;

        MavenProject project = getProject(pom, true);

        assertNotNull(project.getArtifactId());

        assertNotNull(project.getRemoteArtifactRepositories());
        assertTrue(project.getRemoteArtifactRepositories().isEmpty());

        assertNotNull(project.getPluginArtifactRepositories());
        assertTrue(project.getPluginArtifactRepositories().isEmpty());

            String projectId = getId(project);

            MavenProject conflictingProject = projectMap.put(projectId, project);

            if (conflictingProject != null) {
                throw new DuplicateProjectException(
                        projectId,
                        conflictingProject.getFile(),
                        project.getFile(),
                        "Project '" + projectId + "' is duplicated in the reactor");

    }

    public void close() {
        printer.waitUntilRunning(false);
        System.setOut(this.originalSystemOUtStream);
    }

    private void setNext() {
        currentBuild = projects.hasNext() ? projects.next() : null;
    }

    private boolean ownsRealOutputStream(ProjectSegment projectBuild) {
        return projectBuild.equals(currentBuild);
    }

        // compute the projects mapping
        if (projects == null) {
            List<MavenProject> projects = session.getProjects();
            if (projects != null) {
                Map<String, Map<String, Map<String, MavenProject>>> map = new HashMap<>();
                projects.forEach(project -> map.computeIfAbsent(project.getGroupId(), k -> new HashMap<>())

                <property name="test.projects.name" value="basic" />
                <property name="test.projects.version" value="1.0" />
                <property name="test.projects.archetype" value="${test.projects.name}-${test.projects.version}" />
                <property name="test.projects.source.directory" value="${test.projects.archetype}" />

        assertEquals(1, ex1.getResults().size());
        MavenProject project1 = ex1.getResults().get(0).getProject();
        assertNotNull(project1);
        assertEquals("testArtifactMissingVersion", project1.getArtifactId());
        assertEquals(pomFile, project1.getFile());

        // multi projects build entry point
        ProjectBuildingException ex2 = assertThrows(
                ProjectBuildingException.class,