Fetching data node by xpath - rest and service layers

IssueID: CPS-71
Change-Id: I54801fc12a8aa700d85e774780c9990b7f19c747
Signed-off-by: Ruslan Kashapov <ruslan.kashapov@pantheon.tech>

5 files changed, 113 insertions, 13 deletions

diff --git a/cps-rest/docs/api/swagger/components.yaml b/cps-rest/docs/api/swagger/components.yaml
index 3b36b8b2fe..bc7aa57e7a 100644
--- a/cps-rest/docs/api/swagger/components.yaml
+++ b/cps-rest/docs/api/swagger/components.yaml
@@ -62,6 +62,22 @@ components:
       required: true
       schema:
         type: string
+    xpathInQuery:
+      name: cps-path
+      in: query
+      description: cps-path
+      required: false
+      schema:
+        type: string
+        default: /
+    includeDescendantsOptionInQuery:
+      name: include-descendants
+      in: query
+      description: include-descendants
+      required: false
+      schema:
+        type: boolean
+        default: false
 
   responses:
     NotFound:
diff --git a/cps-rest/docs/api/swagger/cpsData.yml b/cps-rest/docs/api/swagger/cpsData.yml
index dcdb99adcb..97bf21a3e8 100644
--- a/cps-rest/docs/api/swagger/cpsData.yml
+++ b/cps-rest/docs/api/swagger/cpsData.yml
@@ -2,11 +2,13 @@ nodesByDataspaceAndAnchor:
   get:
     tags:
       - cps-data
-    summary: Get a node given an anchor for the given dataspace - DRAFT
+    summary: Get a node given an anchor for the given dataspace
     operationId: getNodeByDataspaceAndAnchor
     parameters:
       - $ref: 'components.yaml#/components/parameters/dataspaceNameInPath'
       - $ref: 'components.yaml#/components/parameters/anchorNameInPath'
+      - $ref: 'components.yaml#/components/parameters/xpathInQuery'
+      - $ref: 'components.yaml#/components/parameters/includeDescendantsOptionInQuery'
     responses:
       200:
         $ref: 'components.yaml#/components/responses/Ok'
@@ -49,7 +51,7 @@ nodesByDataspace:
     tags:
       - cps-data
     summary: Get all nodes for a given dataspace using an xpath or schema node identifier - DRAFT
-    operationId: getNode
+    operationId: getNodeByDataspace
     parameters:
       - $ref: 'components.yaml#/components/parameters/dataspaceNameInPath'
     responses:
diff --git a/cps-rest/src/main/java/org/onap/cps/rest/controller/DataRestController.java b/cps-rest/src/main/java/org/onap/cps/rest/controller/DataRestController.java
index 9b31df5637..4f23a8a260 100644
--- a/cps-rest/src/main/java/org/onap/cps/rest/controller/DataRestController.java
+++ b/cps-rest/src/main/java/org/onap/cps/rest/controller/DataRestController.java
@@ -1,6 +1,7 @@
 /*
- * ============LICENSE_START=======================================================
+ *  ============LICENSE_START=======================================================
  *  Copyright (C) 2020 Bell Canada. All rights reserved.
+ *  Modifications Copyright (C) 2021 Pantheon.tech
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -23,6 +24,9 @@ import javax.validation.Valid;
 import javax.validation.constraints.NotNull;
 import org.onap.cps.api.CpsDataService;
 import org.onap.cps.rest.api.CpsDataApi;
+import org.onap.cps.spi.FetchDescendantsOption;
+import org.onap.cps.spi.model.DataNode;
+import org.onap.cps.utils.DataMapUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -44,13 +48,21 @@ public class DataRestController implements CpsDataApi {
     }
 
     @Override
-    public ResponseEntity<Object> getNode(final String dataspaceName) {
+    public ResponseEntity<Object> getNodeByDataspace(final String dataspaceName) {
         return null;
     }
 
     @Override
-    public ResponseEntity<Object> getNodeByDataspaceAndAnchor(final String dataspaceName, final String anchorName) {
-        return null;
+    public ResponseEntity<Object> getNodeByDataspaceAndAnchor(final String dataspaceName, final String anchorName,
+        final String cpsPath, final Boolean includeDescendants) {
+        if ("/".equals(cpsPath)) {
+            // TODO: extracting data by anchor only (root data node and below)
+            return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
+        }
+        final FetchDescendantsOption fetchDescendantsOption = Boolean.TRUE.equals(includeDescendants)
+            ? FetchDescendantsOption.INCLUDE_ALL_DESCENDANTS : FetchDescendantsOption.OMIT_DESCENDANTS;
+        final DataNode dataNode =
+            cpsDataService.getDataNode(dataspaceName, anchorName, cpsPath, fetchDescendantsOption);
+        return new ResponseEntity<>(DataMapUtils.toDataMap(dataNode), HttpStatus.OK);
     }
-
 }
diff --git a/cps-rest/src/main/java/org/onap/cps/rest/exceptions/CpsRestExceptionHandler.java b/cps-rest/src/main/java/org/onap/cps/rest/exceptions/CpsRestExceptionHandler.java
index 2f636630c4..2599dc4f01 100644
--- a/cps-rest/src/main/java/org/onap/cps/rest/exceptions/CpsRestExceptionHandler.java
+++ b/cps-rest/src/main/java/org/onap/cps/rest/exceptions/CpsRestExceptionHandler.java
@@ -27,6 +27,7 @@ import org.onap.cps.rest.model.ErrorMessage;
 import org.onap.cps.spi.exceptions.CpsAdminException;
 import org.onap.cps.spi.exceptions.CpsException;
 import org.onap.cps.spi.exceptions.DataInUseException;
+import org.onap.cps.spi.exceptions.DataNodeNotFoundException;
 import org.onap.cps.spi.exceptions.DataValidationException;
 import org.onap.cps.spi.exceptions.ModelValidationException;
 import org.onap.cps.spi.exceptions.NotFoundInDataspaceException;
@@ -58,7 +59,7 @@ public class CpsRestExceptionHandler {
         return buildErrorResponse(HttpStatus.BAD_REQUEST, exception.getMessage(), extractDetails(exception));
     }
 
-    @ExceptionHandler({NotFoundInDataspaceException.class})
+    @ExceptionHandler({NotFoundInDataspaceException.class, DataNodeNotFoundException.class})
     public static ResponseEntity<Object> handleNotFoundExceptions(final CpsException exception) {
         return buildErrorResponse(HttpStatus.NOT_FOUND, exception.getMessage(), extractDetails(exception));
     }
diff --git a/cps-rest/src/test/groovy/org/onap/cps/rest/controller/DataRestControllerSpec.groovy b/cps-rest/src/test/groovy/org/onap/cps/rest/controller/DataRestControllerSpec.groovy
index f6df3ce9ea..727a16e958 100644
--- a/cps-rest/src/test/groovy/org/onap/cps/rest/controller/DataRestControllerSpec.groovy
+++ b/cps-rest/src/test/groovy/org/onap/cps/rest/controller/DataRestControllerSpec.groovy
@@ -1,6 +1,7 @@
 /*
  *  ============LICENSE_START=======================================================
  *  Copyright (C) 2021 Nordix Foundation
+ *  Modifications Copyright (C) 2021 Pantheon.tech
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -19,10 +20,21 @@
 
 package org.onap.cps.rest.controller
 
+import static org.onap.cps.spi.FetchDescendantsOption.INCLUDE_ALL_DESCENDANTS
+import static org.onap.cps.spi.FetchDescendantsOption.OMIT_DESCENDANTS
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post
+
+import com.google.common.collect.ImmutableMap
 import org.modelmapper.ModelMapper
 import org.onap.cps.api.CpsAdminService
 import org.onap.cps.api.CpsDataService
 import org.onap.cps.api.CpsModuleService
+import org.onap.cps.spi.exceptions.AnchorNotFoundException
+import org.onap.cps.spi.exceptions.DataNodeNotFoundException
+import org.onap.cps.spi.exceptions.DataspaceNotFoundException
+import org.onap.cps.spi.model.DataNode
+import org.onap.cps.spi.model.DataNodeBuilder
 import org.spockframework.spring.SpringBean
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.beans.factory.annotation.Value
@@ -30,9 +42,11 @@ import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest
 import org.springframework.http.HttpStatus
 import org.springframework.http.MediaType
 import org.springframework.test.web.servlet.MockMvc
+import spock.lang.Shared
 import spock.lang.Specification
+import spock.lang.Unroll
 
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post
+import javax.annotation.PostConstruct
 
 @WebMvcTest
 class DataRestControllerSpec extends Specification {
@@ -55,18 +69,73 @@ class DataRestControllerSpec extends Specification {
     @Value('${rest.api.cps-base-path}')
     def basePath
 
+    String dataNodeEndpoint
     def dataspaceName = 'my_dataspace'
     def anchorName = 'my_anchor'
 
+    @Shared
+    static DataNode dataNodeNoChildren = new DataNodeBuilder().withXpath("/xpath")
+            .withLeaves(ImmutableMap.of("leaf", "value")).build()
+
+    @Shared
+    static DataNode dataNodeWithChild = new DataNodeBuilder().withXpath("/parent")
+            .withChildDataNodes(Arrays.asList(
+                    new DataNodeBuilder().withXpath("/parent/child").build()
+            )).build()
+
+    @PostConstruct
+    def initEndpoints() {
+        dataNodeEndpoint = "$basePath/v1/dataspaces/$dataspaceName/anchors/$anchorName/nodes"
+    }
+
     def 'Create a node.'() {
-        given:'an endpoint'
-            def nodeEndpoint ="$basePath/v1/dataspaces/$dataspaceName/anchors/$anchorName/nodes"
+        given: 'an endpoint'
             def json = 'some json (this is not validated)'
         when: 'post is invoked'
-            def response = mvc.perform(post(nodeEndpoint).contentType(MediaType.APPLICATION_JSON).content(json))
-                    .andReturn().response
+            def response = mvc.perform(
+                    post(dataNodeEndpoint).contentType(MediaType.APPLICATION_JSON).content(json)
+            ).andReturn().response
         then: 'the java API is called with the correct parameters'
             1 * mockCpsDataService.saveData(dataspaceName, anchorName, json)
             response.status == HttpStatus.CREATED.value()
     }
+
+    @Unroll
+    def 'Get data node with #scenario.'() {
+        given: 'the service returns data node #scenario'
+            mockCpsDataService.getDataNode(dataspaceName, anchorName, xpath, fetchDescendantsOption) >> dataNode
+        when: 'get request is performed through REST API'
+            def response = mvc.perform(
+                    get(dataNodeEndpoint)
+                            .param('cps-path', xpath)
+                            .param('include-descendants', includeDescendants)
+            ).andReturn().response
+        then: 'assert the success response returned'
+            response.status == HttpStatus.OK.value()
+        and: 'response contains expected value'
+            response.contentAsString.contains(checkString)
+        where:
+            scenario                    | dataNode           | xpath     | includeDescendants | fetchDescendantsOption  || checkString
+            'no descendants by default' | dataNodeNoChildren | '/xpath'  | ''                 | OMIT_DESCENDANTS        || '"leaf"'
+            'no descendant explicitly'  | dataNodeNoChildren | '/xpath'  | 'false'            | OMIT_DESCENDANTS        || '"leaf"'
+            'with descendants'          | dataNodeWithChild  | '/parent' | 'true'             | INCLUDE_ALL_DESCENDANTS || '"child"'
+    }
+
+    @Unroll
+    def 'Get data node error scenario: #scenario.'() {
+        given: 'the service returns throws an exception'
+            mockCpsDataService.getDataNode(dataspaceName, anchorName, xpath, _) >> { throw exception }
+        when: 'get request is performed through REST API'
+            def response = mvc.perform(
+                    get(dataNodeEndpoint).param("cps-path", xpath)
+            ).andReturn().response
+        then: 'assert the success response returned'
+            response.status == httpStatus.value()
+        where:
+            scenario       | xpath     | exception                                 || httpStatus
+            'no dataspace' | '/x-path' | new DataspaceNotFoundException('')        || HttpStatus.BAD_REQUEST
+            'no anchor'    | '/x-path' | new AnchorNotFoundException('', '')       || HttpStatus.BAD_REQUEST
+            'no data'      | '/x-path' | new DataNodeNotFoundException('', '', '') || HttpStatus.NOT_FOUND
+            'empty path'   | ''        | new IllegalStateException()               || HttpStatus.NOT_IMPLEMENTED
+    }
 }
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