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

        this(projects, projects);
    }

    /**
     * Creates a new project dependency graph based on the specified projects.
     *
     * @param allProjects All collected projects.
     * @param projects    The projects to create the dependency graph with.
     * @throws DuplicateProjectException
     * @throws CycleDetectedException
     * @since 3.5.0

    private final Map<String, MavenProject> projects;

    private final Map<String, Integer> indices;

    public ProjectIndex(List<MavenProject> projects) {
        this.projects = new HashMap<>(projects.size() * 2);
        this.indices = new HashMap<>(projects.size() * 2);

        for (int i = 0; i < projects.size(); i++) {
            MavenProject project = projects.get(i);

            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());

        for (MavenProject project : projects) {
            request.setArtifact(new ProjectArtifact(project));
            request.setArtifactDependencies(project.getDependencyArtifacts());
            request.setManagedVersionMap(project.getManagedVersionMap());
            request.setRemoteRepositories(project.getRemoteArtifactRepositories());

    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.MavenProject;
import org.apache.maven.project.ProjectBuilder;
import org.apache.maven.project.ProjectBuildingException;
import org.apache.maven.project.ProjectBuildingRequest;
import org.apache.maven.project.ProjectBuildingResult;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Utility to select projects for a given set of pom.xml files.
 */
@Named

            return new ArrayList<>();
        }
    }

    private Optional<MavenProject> findOptionalProjectBySelector(
            List<MavenProject> projects, File reactorDirectory, String selector) {
        return projects.stream()
                .filter(project -> isMatchingProject(project, selector, reactorDirectory))
                .findFirst();
    }

    File getBaseDirectoryFromRequest(MavenExecutionRequest request) {

        // 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<>())

            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");