*
 * Class is non-{@code final} for testing via stubbing.
 */
public class ResolutionFailureHandler {
    public static final String DEFAULT_MESSAGE_PREFIX = "Review the variant matching algorithm at ";

    private final ResolutionFailureDescriberRegistry defaultFailureDescribers;

    public ResolutionFailureHandler(ResolutionFailureDescriberRegistry failureDescriberRegistry) {

     */
    public GraphVariantSelectionResult selectLegacyConfigurations(ConfigurationMetadata fromConfiguration, ComponentGraphResolveState targetComponent, ResolutionFailureHandler resolutionFailureHandler) {
        // TODO - all this matching stuff is constant for a given DependencyMetadata instance
        List<ConfigurationGraphResolveState> targets = new LinkedList<>();
        boolean matched = false;

        metadata.selectLegacyConfigurations(fromConfig2, toComponent, resolutionFailureHandler).variants == [toConfig2]
    }

    def "configuration mapping can use wildcard on RHS to select all public configurations"() {
        def resolutionFailureHandler = Stub(ResolutionFailureHandler)

        when:
        def conf1State = state.candidatesForGraphVariantSelection.getVariantByConfigurationName("child1", Stub(ResolutionFailureHandler))
        def conf2State = state.candidatesForGraphVariantSelection.getVariantByConfigurationName("child2", Stub(ResolutionFailureHandler))

        then:
        conf1State.resolveArtifacts().artifacts.size() == 3
        conf2State.resolveArtifacts().artifacts.size() == 1

    default VariantGraphResolveState getLegacyVariant(ResolutionFailureHandler failureHandler) {
        return getVariantByConfigurationName(Dependency.DEFAULT_CONFIGURATION, failureHandler);
    }

    /**
     * Returns the variant that is identified by the given configuration name.
     */
    @Nullable
    VariantGraphResolveState getVariantByConfigurationName(String name, ResolutionFailureHandler failureHandler);

 * similar purpose.  An instance of {@link ResolutionFailureHandler} is injected in the constructor
 * to allow the caller to handle failures in a consistent way - all matching failures should be reported via
 * calls to that instance.
 */
public class GraphVariantSelector {
    private final ResolutionFailureHandler failureHandler;

    public GraphVariantSelector(ResolutionFailureHandler failureHandler) {

        for (ModuleResolveState module : resolveState.getModules()) {
            ComponentState selected = module.getSelected();
            if (selected != null) {
                ResolutionFailureHandler resolutionFailureHandler = resolveState.getVariantSelector().getFailureHandler();
                if (selected.isRejected()) {
                    GradleException error = new GradleException(selected.getRejectedErrorMessage());

        return new ResolutionFailureHandler(failureDescriberRegistry);
    }

    @Provides
    GraphVariantSelector createGraphVariantSelector(ResolutionFailureHandler resolutionFailureHandler) {
        return new GraphVariantSelector(resolutionFailureHandler);
    }

    @Provides

            return new ResolutionFailureHandler(failureDescriberRegistry);
        }

        @Provides
        GraphVariantSelector createGraphVariantSelector(ResolutionFailureHandler resolutionFailureHandler) {
            return new GraphVariantSelector(resolutionFailureHandler);
        }

        @Provides
        ConfigurationResolver createDependencyResolver(

            variants.findAll { it -> !it.attributes.isEmpty()}
        }

        @Override
        VariantGraphResolveState getVariantByConfigurationName(String name, ResolutionFailureHandler resolutionFailureHandler) {
            variants.find { it -> it.name == name }
        }
    }