import javax.annotation.Nullable;
import java.util.concurrent.Callable;

/**
 * <p>A {@code ConventionMapping} maintains the convention mappings for the properties of a particular object.</p>
 *
 * <p>Implementations should also allow mappings to be set using dynamic properties.</p>
 */
public interface ConventionMapping {

    MappedProperty map(String propertyName, Closure<?> value);

                }
            }
            tasks.register("mytask", MyTask) {
                def layout = project.layout
                conventionMapping.map("foo") { $directoryExpression }
                conventionMapping.map("bar") { $fileExpression }
            }
        """

        expect:
        succeeds 'mytask'

        where:

public abstract class ConventionTask extends DefaultTask implements IConventionAware {
    private ConventionMapping conventionMapping;

    public Task conventionMapping(String property, Callable<?> mapping) {
        getConventionMapping().map(property, mapping);
        return this;
    }

    public Task conventionMapping(String property, Closure mapping) {
        getConventionMapping().map(property, mapping);
        return this;

            taskReportTask.setDescription("Generates a report about your tasks.");
            taskReportTask.conventionMapping("outputFile", () -> taskReportTask.getProjectReportDirectory().file("tasks.txt").get().getAsFile());
            taskReportTask.conventionMapping("projects", () -> WrapUtil.toSet(project));
        });

        return extensionContainer;
    }

    @Override
    public ConventionMapping getConventionMapping() {
        if (conventionMapping == null) {
            this.conventionMapping = DeprecationLogger.whileDisabled(() ->
                toType(object, IConventionAware.class).getConventionMapping()
            );
        }
        return conventionMapping;
    }

    public Class<?> getDeclaredType() {

            ConventionMapping conventionMapping = ((IConventionAware) ideaProject).getConventionMapping();
            conventionMapping.map("jdkName", new Callable<String>() {
                @Override
                public String call() {
                    return JavaVersion.current().toString();
                }
            });

        ConventionMapping conventionMapping = compile.getConventionMapping();
        conventionMapping.map("sourceCompatibility", () -> computeSourceCompatibilityConvention(javaExtension, compatibilityComputer).toString());

        expect:
        task.getConventionMapping() instanceof ConventionAwareHelper

        when:
        ConventionAwareHelper conventionMapping = (ConventionAwareHelper) task.getConventionMapping();

        then:
        conventionMapping.getConvention().is(task.getConvention())
    }

        project.getTasks().withType(ScalaCompile.class).configureEach(compile -> {
            ConventionMapping conventionMapping = compile.getConventionMapping();
            conventionMapping.map("scalaClasspath", (Callable<FileCollection>) () -> scalaRuntime.inferScalaClasspath(compile.getClasspath()));
            conventionMapping.map("zincClasspath", (Callable<Configuration>) () -> project.getConfigurations().getAt(ZINC_CONFIGURATION_NAME));

                    assert foo.files == layout.files("file1", "file2").files
                    assert foo.files.size() == 2
                }
            }
            tasks.register("mytask", MyTask) {
                conventionMapping.map("foo") { bar }
                bar.setFrom("file1", "file2")
            }
        """

        expect:
        succeeds 'mytask'
    }