Introduce JUnit5 extension for writing old core tests

@OldcoreTest
public class WikiUIExtensionComponentBuilderTest implements WikiUIExtensionConstants
{
    @InjectMockComponents
    private WikiUIExtensionComponentBuilder builder;

    private static final DocumentReference DOC_REF =
        new DocumentReference("xwiki", "XWiki", "MyUIExtension", Locale.ROOT);

    private static final DocumentReference AUTHOR_REFERENCE = new DocumentReference("xwiki", "XWiki", "Admin");

    private XWikiDocument componentDoc;

    @BeforeComponent
    public void configure(MockitoComponentManager componentManager, MockitoOldcore oldcore) throws Exception
    {
        // Required by BaseObjectReference
        DocumentReferenceResolver<String> resolver =
            componentManager.registerMockComponent(DocumentReferenceResolver.TYPE_STRING);
        when(resolver.resolve("XWiki.UIExtension"))
            .thenReturn(new DocumentReference("xwiki", "XWiki", "UIExtensionClass"));

        DelegateComponentManager wikiComponentManager = new DelegateComponentManager();
        wikiComponentManager.setComponentManager(componentManager);
        componentManager.registerComponent(ComponentManager.class, "wiki", wikiComponentManager);

        // Components accessed through dynamic lookup.
        VelocityManager velocityManager = componentManager.registerMockComponent(VelocityManager.class);
        when(velocityManager.getVelocityEngine()).thenReturn(mock(VelocityEngine.class));
        when(velocityManager.getVelocityContext()).thenReturn(mock(VelocityContext.class));

        ModelContext modelContext = componentManager.registerMockComponent(ModelContext.class);
        when(modelContext.getCurrentEntityReference()).thenReturn(DOC_REF);

        componentManager.registerMockComponent(RenderingContext.class);
        componentManager.registerMockComponent(Transformation.class, "macro");
        componentManager.registerMockComponent(ContentParser.class);

        // The document holding the UI extension object.
        this.componentDoc = mock(XWikiDocument.class, "xwiki:XWiki.MyUIExtension");
        when(this.componentDoc.getDocumentReference()).thenReturn(DOC_REF);
        when(this.componentDoc.getAuthorReference()).thenReturn(AUTHOR_REFERENCE);
        when(this.componentDoc.getContentAuthorReference()).thenReturn(AUTHOR_REFERENCE);
        when(this.componentDoc.getSyntax()).thenReturn(Syntax.XWIKI_2_1);
        oldcore.getDocuments().put(DOC_REF, componentDoc);
    }

    @Test
    public void buildGlobalComponentsWithoutPR()
    {
        BaseObject extensionObject = createExtensionObject("id", "extensionPointId", "content", "parameters", "global");
        Throwable exception = assertThrows(WikiComponentException.class, () -> {
            this.builder.buildComponents(extensionObject);
        });
        assertEquals("Registering global UI extensions requires programming rights", exception.getMessage());
    }

    @Test
    public void buildWikiLevelComponentsWithoutAdminRights()
    {
        BaseObject extensionObject = createExtensionObject("id", "extensionPointId", "content", "parameters", "wiki");
        Throwable exception = assertThrows(WikiComponentException.class, () -> {
            this.builder.buildComponents(extensionObject);
        });
        assertEquals("Registering UI extensions at wiki level requires wiki administration rights",
            exception.getMessage());
    }

    @Test
    public void buildComponents(ComponentManager componentManager) throws Exception
    {
        BaseObject extensionObject = createExtensionObject("name", "extensionPointId", "content",
            "key=value=foo\nkey2=value2\ninvalid=\n\n=invalid", "user");

        ContentParser contentParser = componentManager.getInstance(ContentParser.class);
        VelocityManager velocityManager = componentManager.getInstance(VelocityManager.class);

        List<WikiComponent> components = this.builder.buildComponents(extensionObject);

        assertEquals(1, components.size());
        verify(contentParser).parse("content", Syntax.XWIKI_2_1, DOC_REF);

        UIExtension uiExtension = (UIExtension) components.get(0);
        Map<String, String> parameters = uiExtension.getParameters();

        assertEquals(2, parameters.size());
        verify(velocityManager.getVelocityEngine()).evaluate(any(VelocityContext.class), any(StringWriter.class),
            eq("name:key"), eq("value=foo"));
        verify(velocityManager.getVelocityEngine()).evaluate(any(VelocityContext.class), any(StringWriter.class),
            eq("name:key2"), eq("value2"));
    }

    private BaseObject createExtensionObject(String id, String extensionPointId, String content, String parameters,
        String scope)
    {
        BaseObject extensionObject = mock(BaseObject.class, id);
        when(extensionObject.getStringValue(ID_PROPERTY)).thenReturn(id);
        when(extensionObject.getStringValue(EXTENSION_POINT_ID_PROPERTY)).thenReturn(extensionPointId);
        when(extensionObject.getStringValue(CONTENT_PROPERTY)).thenReturn(content);
        when(extensionObject.getStringValue(PARAMETERS_PROPERTY)).thenReturn(parameters);
        when(extensionObject.getStringValue(SCOPE_PROPERTY)).thenReturn(scope);
        BaseObjectReference objectReference =
            new BaseObjectReference(new ObjectReference("XWiki.UIExtensionClass[0]", DOC_REF));
        when(extensionObject.getReference()).thenReturn(objectReference);

        when(extensionObject.getOwnerDocument()).thenReturn(this.componentDoc);

        return extensionObject;
    }
}