* it delegates to other components that potentially encounter problems. Then, the problem reporter can focus on
 * providing a simple error message, leaving the donkey work of creating a nice model problem to this component.
 *
 */
public interface ModelProblemCollector {

    /**
     * The collected problems.

     */
    @Nonnull
    List<ModelProblem> getProblems();

    /**
     * Creates a human readable representation of these errors.
     */
    String toString();

        } catch (ExpressionEvaluationException e) {
            // not important
            // will be reported during Mojo fields populate
        }

        // fallback - in case of error in expressionEvaluator
        return false;
    }

    @Override
    public final void validate(
            MavenSession mavenSession,
            MojoDescriptor mojoDescriptor,
            Class<?> mojoClass,

 * that exhibits the problem.
 *
 */
public interface Problem {

    /**
     * The different severity levels for a problem, in decreasing order.
     */
    enum Severity {
        FATAL, //
        ERROR, //
        WARNING //
    }

    /**
     * Gets the hint about the source of the problem. While the syntax of this hint is unspecified and depends on the

     * @param path path to the JAR file or output directory of the dependency
     * @return where to place the dependency, or an empty value if the placement cannot be determined
     * @throws IOException if an error occurred while reading module information
     */
    Optional<PathType> selectPathType(Set<PathType> types, Predicate<PathType> filter, Path path) throws IOException {
        PathType selected = null;

        try {
            updateRepositoryMetadata(localRepository, remoteRepository);
        } catch (IOException | XMLStreamException e) {
            throw new RepositoryMetadataStoreException("Error updating group repository metadata", e);
        }
    }

    protected void updateRepositoryMetadata(ArtifactRepository localRepository, ArtifactRepository remoteRepository)

        descriptor.setArtifactId("maven-it-plugin");
        descriptor.setVersion("0.1");
        List<String> errors = new ArrayList<>();
        mavenPluginValidator.validate(plugin, descriptor, errors);
        assertTrue(errors.isEmpty());
    }

    @Test
    void testInvalidGroupId() {
        Artifact plugin = new DefaultArtifact(
                "org.apache.maven.its.plugins",

        if (!pluginArtifact.getGroupId().equals(pluginDescriptor.getGroupId())) {
            errors.add("Plugin's descriptor contains the wrong group ID: " + pluginDescriptor.getGroupId());
        }

        if (!pluginArtifact.getArtifactId().equals(pluginDescriptor.getArtifactId())) {

 * <ul>
 *   <li>missing metadata</li>
 *   <li>version range violations</li>
 *   <li>version circular dependencies</li>
 *   <li>missing artifacts</li>
 *   <li>network/transfer errors</li>
 *   <li>file system errors: permissions</li>
 * </ul>
 *
 * TODO carlos: all these possible has*Exceptions and get*Exceptions methods make the clients too

                                    e.getModelId(), e.getMessage(), pomFile != null ? pomFile.toFile() : null, e);
                        }
                        // validation error, continue project building and delay failing to help IDEs
                        error = e;
                    }

                    modelProblems = result.getProblems();

                    initProject(project, Collections.emptyMap(), result);