Exception handling on REST unit test

Issue-ID: CPS-41
JIRA: https://jira.onap.org/browse/CPS-41
Change-Id: Ieda9c14b7e9c5962bf0b39c168de4c5cc7929d80
Signed-off-by: Ruslan Kashapov <ruslan.kashapov@pantheon.tech>

1 files changed, 115 insertions, 0 deletions

diff --git a/cps-rest/src/test/groovy/org/onap/cps/rest/exceptions/CpsRestExceptionHandlerSpec.groovy b/cps-rest/src/test/groovy/org/onap/cps/rest/exceptions/CpsRestExceptionHandlerSpec.groovy
new file mode 100644
index 000000000..dd1b956d8
--- /dev/null
+++ b/cps-rest/src/test/groovy/org/onap/cps/rest/exceptions/CpsRestExceptionHandlerSpec.groovy
@@ -0,0 +1,115 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Pantheon.tech
+ *  ================================================================================
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.rest.exceptions
+
+import groovy.json.JsonSlurper
+import org.onap.cps.api.CpService
+import org.onap.cps.exceptions.CpsException
+import org.onap.cps.exceptions.CpsNotFoundException
+import org.onap.cps.exceptions.CpsValidationException
+import org.onap.cps.rest.controller.CpsRestController
+import spock.lang.Specification
+
+import static org.springframework.http.HttpStatus.BAD_REQUEST
+import static org.springframework.http.HttpStatus.INTERNAL_SERVER_ERROR
+import static org.springframework.http.HttpStatus.NOT_FOUND
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.standaloneSetup
+
+class CpsRestExceptionHandlerSpec extends Specification {
+
+    def cpsRestController = new CpsRestController();
+    def mockCpService = Mock(CpService.class)
+    def objectUnderTest = new CpsRestExceptionHandler();
+    def mockMvc = standaloneSetup(cpsRestController).setControllerAdvice(objectUnderTest).build()
+
+    def setup() {
+        cpsRestController.cpService = mockCpService
+    }
+
+    def 'Get request with runtime exception returns HTTP Status Internal Server Error'() {
+
+        when: 'runtime exception is thrown by the service'
+            def errorMessage = 'runtime error message'
+            setupTestException(new IllegalStateException(errorMessage))
+            def response = performTestRequest()
+
+        then: 'an HTTP Internal Server Error response is returned with the correct message'
+            assertTestResponse(response, INTERNAL_SERVER_ERROR, errorMessage, null)
+    }
+
+    def 'Get request with generic CPS exception returns HTTP Status Internal Server Error'() {
+
+        when: 'generic CPS exception is thrown by the service'
+            def errorMessage = 'cps generic error message'
+            def errorDetails = 'cps generic error details'
+            setupTestException(new CpsException(errorMessage, errorDetails))
+            def response = performTestRequest()
+
+        then: 'an HTTP Internal Server Error response is returned with the correct message'
+            assertTestResponse(response, INTERNAL_SERVER_ERROR, errorMessage, errorDetails)
+    }
+
+    def 'Get request with no data found CPS exception returns HTTP Status Not Found'() {
+
+        when: 'no data found CPS exception is thrown by the service'
+            def errorMessage = 'cps no data error message'
+            def errorDetails = 'cps no data error details'
+            setupTestException(new CpsNotFoundException(errorMessage, errorDetails))
+            def response = performTestRequest()
+
+        then: 'an HTTP Not Found response is returned with the correct message'
+            assertTestResponse(response, NOT_FOUND, errorMessage, errorDetails)
+    }
+
+    def 'Get request with CPS validation exception returns HTTP Status Bad Request'() {
+
+        when: 'CPS validation exception is thrown by the service'
+            def errorMessage = 'cps validation error message'
+            def errorDetails = 'cps validation error details'
+            setupTestException(new CpsValidationException(errorMessage, errorDetails))
+            def response = performTestRequest()
+
+        then: 'an HTTP Bad Request response is returned with the correct message'
+            assertTestResponse(response, BAD_REQUEST, errorMessage, errorDetails)
+    }
+
+    /*
+     * NB. The test uses 'get JSON by id' endpoint and associated service method invocation
+     * to test the exception handling. The endpoint chosen is not a subject of test.
+     */
+
+    def setupTestException(exception) {
+        mockCpService.getJsonById(_) >> { throw exception }
+    }
+
+    def performTestRequest() {
+        return mockMvc.perform(get('/json-object/1')).andReturn().response
+    }
+
+    void assertTestResponse(response, expectedStatus, expectedErrorMessage, expectedErrorDetails) {
+        assert response.status == expectedStatus.value()
+        def content = new JsonSlurper().parseText(response.contentAsString)
+        assert content['status'] == expectedStatus.toString()
+        assert content['message'] == expectedErrorMessage
+        assert expectedErrorDetails == null || content['details'] == expectedErrorDetails
+    }
+    
+}