ACS-4028 GET Category by id (#1601)

* ACS-4028 Get category by id (#1591)

* ACS-4028: Get category by id endpoint.

* ACS-4028: Get category by id endpoint.

* ACS-4028: Get category by id endpoint - integration TAS tests.

* ACS-4028: Get category by id endpoint - refactoring.

* ACS-4028: Adding test to test suite.

* ACS-4028: Fixes after code review.

* ACS-4019: Removing redundant test group.

remote-api/src/main/java/org/alfresco/rest/api/Categories.java

@@ -0,0 +1,38 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2022 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+
+package org.alfresco.rest.api;
+
+import org.alfresco.rest.api.model.Category;
+import org.alfresco.rest.framework.resource.parameters.Parameters;
+import org.alfresco.service.Experimental;
+import org.alfresco.service.cmr.repository.NodeRef;
+
+@Experimental
+public interface Categories
+{
+    Category getCategoryById(String id, Parameters params);
+}

remote-api/src/main/java/org/alfresco/rest/api/categories/CategoriesEntityResource.java

@@ -0,0 +1,61 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2016 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package org.alfresco.rest.api.categories;
+
+import javax.servlet.http.HttpServletResponse;
+
+import org.alfresco.rest.api.Categories;
+import org.alfresco.rest.api.model.Category;
+import org.alfresco.rest.framework.WebApiDescription;
+import org.alfresco.rest.framework.core.exceptions.EntityNotFoundException;
+import org.alfresco.rest.framework.resource.EntityResource;
+import org.alfresco.rest.framework.resource.actions.interfaces.EntityResourceAction;
+import org.alfresco.rest.framework.resource.parameters.Parameters;
+
+/**
+ * Entity Resource for Categories
+ *
+ * @author mpichura
+ */
+@EntityResource(name = "categories", title = "Categories")
+public class CategoriesEntityResource implements EntityResourceAction.ReadById<Category>
+{
+    private final Categories categories;
+
+    public CategoriesEntityResource(Categories categories)
+    {
+        this.categories = categories;
+    }
+
+    @WebApiDescription(title = "Get category by its id",
+            description = "Retrieves a category given category node id",
+            successStatus = HttpServletResponse.SC_OK)
+    @Override
+    public Category readById(String id, Parameters parameters) throws EntityNotFoundException
+    {
+        return categories.getCategoryById(id, parameters);
+    }
+}

remote-api/src/main/java/org/alfresco/rest/api/categories/package-info.java

@@ -0,0 +1,30 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2022 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+@WebApi(name = "alfresco", scope = Api.SCOPE.PUBLIC, version = 1)
+package org.alfresco.rest.api.categories;
+
+import org.alfresco.rest.framework.Api;
+import org.alfresco.rest.framework.WebApi;

remote-api/src/main/java/org/alfresco/rest/api/impl/CategoriesImpl.java

@@ -0,0 +1,93 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2022 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+
+package org.alfresco.rest.api.impl;
+
+import static org.alfresco.rest.api.Nodes.PATH_ROOT;
+
+import java.util.List;
+
+import org.alfresco.model.ContentModel;
+import org.alfresco.rest.api.Categories;
+import org.alfresco.rest.api.Nodes;
+import org.alfresco.rest.api.model.Category;
+import org.alfresco.rest.api.model.Node;
+import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
+import org.alfresco.rest.framework.resource.parameters.Parameters;
+import org.alfresco.service.Experimental;
+import org.alfresco.service.cmr.repository.ChildAssociationRef;
+import org.alfresco.service.cmr.repository.NodeRef;
+import org.alfresco.service.cmr.repository.NodeService;
+import org.alfresco.service.namespace.RegexQNamePattern;
+import org.apache.commons.collections.CollectionUtils;
+
+@Experimental
+public class CategoriesImpl implements Categories
+{
+    static final String NOT_A_VALID_CATEGORY = "Node id does not refer to a valid category";
+
+    private final Nodes nodes;
+    private final NodeService nodeService;
+
+    public CategoriesImpl(Nodes nodes, NodeService nodeService)
+    {
+        this.nodes = nodes;
+        this.nodeService = nodeService;
+    }
+
+    @Override
+    public Category getCategoryById(final String id, final Parameters params)
+    {
+        final NodeRef nodeRef = nodes.validateNode(id);
+        final boolean isCategory = nodes.isSubClass(nodeRef, ContentModel.TYPE_CATEGORY, false);
+        if (!isCategory || isRootCategory(nodeRef))
+        {
+            throw new InvalidArgumentException(NOT_A_VALID_CATEGORY, new String[]{id});
+        }
+        final Node categoryNode = nodes.getNode(nodeRef.getId());
+        final Category category = new Category();
+        category.setId(nodeRef.getId());
+        category.setName(categoryNode.getName());
+        category.setParentId(getParentId(nodeRef));
+        final boolean hasChildren = CollectionUtils
+                .isNotEmpty(nodeService.getChildAssocs(nodeRef, RegexQNamePattern.MATCH_ALL, RegexQNamePattern.MATCH_ALL, false));
+        category.setHasChildren(hasChildren);
+
+        return category;
+    }
+
+    private boolean isRootCategory(final NodeRef nodeRef)
+    {
+        final List<ChildAssociationRef> parentAssocs = nodeService.getParentAssocs(nodeRef);
+        return parentAssocs.stream().anyMatch(pa -> pa.getQName().equals(ContentModel.ASPECT_GEN_CLASSIFIABLE));
+    }
+
+    private String getParentId(final NodeRef nodeRef)
+    {
+        final NodeRef parentRef = nodeService.getPrimaryParent(nodeRef).getParentRef();
+        return isRootCategory(parentRef) ? PATH_ROOT : parentRef.getId();
+    }
+}

remote-api/src/main/java/org/alfresco/rest/api/model/Category.java

@@ -0,0 +1,75 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2022 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+
+package org.alfresco.rest.api.model;
+
+public class Category
+{
+    private String id;
+    private String name;
+    private String parentId;
+    private boolean hasChildren;
+
+    public String getId()
+    {
+        return id;
+    }
+
+    public void setId(String id)
+    {
+        this.id = id;
+    }
+
+    public String getName()
+    {
+        return name;
+    }
+
+    public void setName(String name)
+    {
+        this.name = name;
+    }
+
+    public String getParentId()
+    {
+        return parentId;
+    }
+
+    public void setParentId(String parentId)
+    {
+        this.parentId = parentId;
+    }
+
+    public boolean getHasChildren()
+    {
+        return hasChildren;
+    }
+
+    public void setHasChildren(boolean hasChildren)
+    {
+        this.hasChildren = hasChildren;
+    }
+}

remote-api/src/main/resources/alfresco/public-rest-context.xml

@@ -828,7 +828,26 @@
             </list>
         </property>
     </bean>
-    
+
+    <bean id="categories" class="org.alfresco.rest.api.impl.CategoriesImpl">
+        <constructor-arg name="nodes" ref="nodes"/>
+        <constructor-arg name="nodeService" ref="NodeService"/>
+    </bean>
+
+    <bean id="Categories" class="org.springframework.aop.framework.ProxyFactoryBean">
+        <property name="proxyInterfaces">
+            <value>org.alfresco.rest.api.Categories</value>
+        </property>
+        <property name="target">
+            <ref bean="categories"/>
+        </property>
+        <property name="interceptorNames">
+            <list>
+                <idref bean="legacyExceptionInterceptor"/>
+            </list>
+        </property>
+    </bean>
+
     <bean id="tags" class="org.alfresco.rest.api.impl.TagsImpl">
         <property name="nodes" ref="nodes" />
         <property name="taggingService" ref="TaggingService" />
@@ -1075,11 +1094,15 @@
     <bean class="org.alfresco.rest.api.people.PersonGroupsRelation">
         <property name="groups" ref="Groups" />
     </bean>
-	
+
+    <bean class="org.alfresco.rest.api.categories.CategoriesEntityResource">
+        <constructor-arg name="categories" ref="Categories"/>
+    </bean>
+
     <bean class="org.alfresco.rest.api.tags.TagsEntityResource">
         <property name="tags" ref="Tags" />
     </bean>
-	
+
     <bean class="org.alfresco.rest.api.people.PersonSitesRelation">
         <property name="sites" ref="Sites" />
     </bean>

remote-api/src/test/java/org/alfresco/rest/api/categories/CategoriesEntityResourceTest.java

@@ -0,0 +1,68 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2022 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+
+package org.alfresco.rest.api.categories;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.then;
+
+import org.alfresco.rest.api.Categories;
+import org.alfresco.rest.api.model.Category;
+import org.alfresco.rest.framework.resource.parameters.Parameters;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+@RunWith(MockitoJUnitRunner.class)
+public class CategoriesEntityResourceTest
+{
+    private static final String CATEGORY_ID = "category-node-id";
+    @Mock
+    private Categories categoriesMock;
+    @Mock
+    private Category categoryMock;
+    @Mock
+    private Parameters parametersMock;
+
+    @InjectMocks
+    private CategoriesEntityResource objectUnderTest;
+
+    @Test
+    public void testReadCategoryById()
+    {
+        given(categoriesMock.getCategoryById(CATEGORY_ID, parametersMock)).willReturn(categoryMock);
+
+        //when
+        final Category category = objectUnderTest.readById(CATEGORY_ID, parametersMock);
+
+        then(categoriesMock).should().getCategoryById(CATEGORY_ID, parametersMock);
+        then(categoriesMock).shouldHaveNoMoreInteractions();
+        assertEquals(categoryMock, category);
+    }
+}

remote-api/src/test/java/org/alfresco/rest/api/impl/CategoriesImplTest.java

@@ -0,0 +1,201 @@
+/*
+ * #%L
+ * Alfresco Remote API
+ * %%
+ * Copyright (C) 2005 - 2022 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+
+package org.alfresco.rest.api.impl;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.then;
+
+import java.util.Collections;
+import java.util.List;
+
+import org.alfresco.model.ContentModel;
+import org.alfresco.rest.api.Nodes;
+import org.alfresco.rest.api.model.Category;
+import org.alfresco.rest.api.model.Node;
+import org.alfresco.rest.framework.core.exceptions.EntityNotFoundException;
+import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
+import org.alfresco.rest.framework.resource.parameters.Parameters;
+import org.alfresco.service.cmr.repository.ChildAssociationRef;
+import org.alfresco.service.cmr.repository.NodeRef;
+import org.alfresco.service.cmr.repository.NodeService;
+import org.alfresco.service.cmr.repository.StoreRef;
+import org.alfresco.service.namespace.RegexQNamePattern;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+@RunWith(MockitoJUnitRunner.class)
+public class CategoriesImplTest
+{
+    private static final String CATEGORY_ID = "category-node-id";
+    private static final String CATEGORY_NAME = "categoryName";
+    private static final String PARENT_ID = "parent-node-id";
+    private static final String CAT_ROOT_NODE_ID = "cat-root-node-id";
+
+    @Mock
+    private Nodes nodesMock;
+    @Mock
+    private NodeService nodeServiceMock;
+    @Mock
+    private Parameters parametersMock;
+    @Mock
+    private ChildAssociationRef dummyChildAssociationRefMock;
+    @Mock
+    private ChildAssociationRef categoryChildAssociationRefMock;
+
+    @InjectMocks
+    private CategoriesImpl objectUnderTest;
+
+    @Test
+    public void shouldNotGetRootCategoryById()
+    {
+        final NodeRef categoryRootNodeRef = new NodeRef(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE, CAT_ROOT_NODE_ID);
+        given(nodesMock.validateNode(CAT_ROOT_NODE_ID)).willReturn(categoryRootNodeRef);
+        given(nodesMock.isSubClass(categoryRootNodeRef, ContentModel.TYPE_CATEGORY, false)).willReturn(true);
+        given(categoryChildAssociationRefMock.getQName()).willReturn(ContentModel.ASPECT_GEN_CLASSIFIABLE);
+        given(nodeServiceMock.getParentAssocs(categoryRootNodeRef)).willReturn(List.of(categoryChildAssociationRefMock));
+
+        //when
+        assertThrows(InvalidArgumentException.class, () -> objectUnderTest.getCategoryById(CAT_ROOT_NODE_ID, parametersMock));
+
+        then(nodesMock).should().validateNode(CAT_ROOT_NODE_ID);
+        then(nodesMock).should().isSubClass(categoryRootNodeRef, ContentModel.TYPE_CATEGORY, false);
+        then(nodesMock).shouldHaveNoMoreInteractions();
+        then(nodeServiceMock).should().getParentAssocs(categoryRootNodeRef);
+        then(nodeServiceMock).shouldHaveNoMoreInteractions();
+    }
+
+    @Test
+    public void testGetCategoryById_withChildren()
+    {
+        final NodeRef categoryNodeRef = new NodeRef(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE, CATEGORY_ID);
+        given(nodesMock.validateNode(CATEGORY_ID)).willReturn(categoryNodeRef);
+        given(nodesMock.isSubClass(categoryNodeRef, ContentModel.TYPE_CATEGORY, false)).willReturn(true);
+        final Node categoryNode = new Node();
+        categoryNode.setName(CATEGORY_NAME);
+        categoryNode.setNodeId(CATEGORY_ID);
+        final NodeRef parentNodeRef = new NodeRef(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE, PARENT_ID);
+        categoryNode.setParentId(parentNodeRef);
+        given(nodesMock.getNode(CATEGORY_ID)).willReturn(categoryNode);
+        final ChildAssociationRef parentAssoc = new ChildAssociationRef(null, parentNodeRef, null, categoryNodeRef);
+        given(nodeServiceMock.getPrimaryParent(categoryNodeRef)).willReturn(parentAssoc);
+        final List<ChildAssociationRef> dummyChildren = List.of(dummyChildAssociationRefMock);
+        given(nodeServiceMock.getChildAssocs(categoryNodeRef, RegexQNamePattern.MATCH_ALL, RegexQNamePattern.MATCH_ALL, false))
+                .willReturn(dummyChildren);
+        //when
+        final Category category = objectUnderTest.getCategoryById(CATEGORY_ID, parametersMock);
+
+        then(nodesMock).should().validateNode(CATEGORY_ID);
+        then(nodesMock).should().isSubClass(categoryNodeRef, ContentModel.TYPE_CATEGORY, false);
+        then(nodesMock).should().getNode(CATEGORY_ID);
+        then(nodesMock).shouldHaveNoMoreInteractions();
+
+        then(nodeServiceMock).should().getPrimaryParent(categoryNodeRef);
+        then(nodeServiceMock).should().getParentAssocs(parentNodeRef);
+        then(nodeServiceMock).should().getParentAssocs(categoryNodeRef);
+        then(nodeServiceMock).should().getChildAssocs(categoryNodeRef, RegexQNamePattern.MATCH_ALL, RegexQNamePattern.MATCH_ALL, false);
+        then(nodeServiceMock).shouldHaveNoMoreInteractions();
+
+        assertEquals(categoryNode.getName(), category.getName());
+        assertEquals(CATEGORY_ID, category.getId());
+        assertEquals(PARENT_ID, category.getParentId());
+        assertTrue(category.getHasChildren());
+    }
+
+    @Test
+    public void testGetCategoryById_withoutChildren()
+    {
+        final NodeRef categoryNodeRef = new NodeRef(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE, CATEGORY_ID);
+        given(nodesMock.validateNode(CATEGORY_ID)).willReturn(categoryNodeRef);
+        given(nodesMock.isSubClass(categoryNodeRef, ContentModel.TYPE_CATEGORY, false)).willReturn(true);
+        final Node categoryNode = new Node();
+        categoryNode.setName(CATEGORY_NAME);
+        categoryNode.setNodeId(CATEGORY_ID);
+        final NodeRef parentNodeRef = new NodeRef(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE, PARENT_ID);
+        categoryNode.setParentId(parentNodeRef);
+        given(nodesMock.getNode(CATEGORY_ID)).willReturn(categoryNode);
+        final ChildAssociationRef parentAssoc = new ChildAssociationRef(null, parentNodeRef, null, categoryNodeRef);
+        given(nodeServiceMock.getPrimaryParent(categoryNodeRef)).willReturn(parentAssoc);
+        given(nodeServiceMock.getChildAssocs(categoryNodeRef, RegexQNamePattern.MATCH_ALL, RegexQNamePattern.MATCH_ALL, false))
+                .willReturn(Collections.emptyList());
+        //when
+        final Category category = objectUnderTest.getCategoryById(CATEGORY_ID, parametersMock);
+
+        then(nodesMock).should().validateNode(CATEGORY_ID);
+        then(nodesMock).should().isSubClass(categoryNodeRef, ContentModel.TYPE_CATEGORY, false);
+        then(nodesMock).should().getNode(CATEGORY_ID);
+        then(nodesMock).shouldHaveNoMoreInteractions();
+
+        then(nodeServiceMock).should().getPrimaryParent(categoryNodeRef);
+        then(nodeServiceMock).should().getParentAssocs(parentNodeRef);
+        then(nodeServiceMock).should().getParentAssocs(categoryNodeRef);
+        then(nodeServiceMock).should().getChildAssocs(categoryNodeRef, RegexQNamePattern.MATCH_ALL, RegexQNamePattern.MATCH_ALL, false);
+        then(nodeServiceMock).shouldHaveNoMoreInteractions();
+
+        assertEquals(categoryNode.getName(), category.getName());
+        assertEquals(CATEGORY_ID, category.getId());
+        assertEquals(PARENT_ID, category.getParentId());
+        assertFalse(category.getHasChildren());
+    }
+
+    @Test
+    public void testGetCategoryById_notACategory()
+    {
+        final NodeRef categoryNodeRef = new NodeRef(StoreRef.STORE_REF_WORKSPACE_SPACESSTORE, CATEGORY_ID);
+        given(nodesMock.validateNode(CATEGORY_ID)).willReturn(categoryNodeRef);
+        given(nodesMock.isSubClass(categoryNodeRef, ContentModel.TYPE_CATEGORY, false)).willReturn(false);
+
+        //when
+        assertThrows(InvalidArgumentException.class, () -> objectUnderTest.getCategoryById(CATEGORY_ID, parametersMock));
+
+        then(nodesMock).should().validateNode(CATEGORY_ID);
+        then(nodesMock).should().isSubClass(categoryNodeRef, ContentModel.TYPE_CATEGORY, false);
+        then(nodesMock).shouldHaveNoMoreInteractions();
+
+        then(nodeServiceMock).shouldHaveNoInteractions();
+    }
+
+    @Test
+    public void testGetCategoryById_nodeNotExists()
+    {
+        given(nodesMock.validateNode(CATEGORY_ID)).willThrow(EntityNotFoundException.class);
+
+        //when
+        assertThrows(EntityNotFoundException.class, () -> objectUnderTest.getCategoryById(CATEGORY_ID, parametersMock));
+
+        then(nodesMock).should().validateNode(CATEGORY_ID);
+        then(nodesMock).shouldHaveNoMoreInteractions();
+
+        then(nodeServiceMock).shouldHaveNoInteractions();
+    }
+}