Adding Unit Test Cases For Optimizer REST APIs

pom.xml

@@ -89,6 +89,16 @@
             <artifactId>rest-assured</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit-mockito</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

src/test/README.md

@@ -0,0 +1,31 @@
+# Test Suite
+
+This directory contains tests for the Kruize Optimizer application.
+
+## Prerequisites
+
+- Java 25 or higher
+
+## Running Tests
+
+### Run All Tests
+```bash
+./mvnw test
+```
+
+### Run Specific Test Class
+```bash
+./mvnw test -Dtest=DatasourceResourceTest
+./mvnw test -Dtest=LayerResourceTest
+./mvnw test -Dtest=MetadataProfileResourceTest
+./mvnw test -Dtest=MetricProfileResourceTest
+```
+
+### Run Single Test Method
+```bash
+./mvnw test -Dtest=DatasourceResourceTest#testListDatasources_Success
+```
+
+## Test Approach
+
+Tests mock the Kruize API client responses using JSON files. This allows testing without a running Kruize service. The application's business logic is tested, while external API calls are mocked.

src/test/java/com/kruize/optimizer/resource/DatasourceResourceTest.java

@@ -0,0 +1,208 @@
+/*******************************************************************************
+ * Copyright (c) 2026 IBM Corporation and others.
+ *
+ * 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.
+ *******************************************************************************/
+package com.kruize.optimizer.resource;
+
+import com.kruize.optimizer.client.KruizeClient;
+import com.kruize.optimizer.model.api.DatasourceListResponse;
+import com.kruize.optimizer.service.BulkSchedulerService;
+import com.kruize.optimizer.service.KruizeStateService;
+import com.kruize.optimizer.util.MockResponseLoader;
+import io.quarkus.test.InjectMock;
+import io.quarkus.test.junit.QuarkusTest;
+import io.restassured.http.ContentType;
+import org.eclipse.microprofile.rest.client.inject.RestClient;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import java.io.IOException;
+
+import static io.restassured.RestAssured.given;
+import static org.hamcrest.Matchers.*;
+import static org.mockito.Mockito.*;
+
+/**
+ * Integration tests for DatasourceResource using mock JSON responses
+ */
+@QuarkusTest
+class DatasourceResourceTest {
+
+    @InjectMock
+    BulkSchedulerService bulkSchedulerService;
+
+    @InjectMock
+    KruizeStateService kruizeStateService;
+
+    @InjectMock
+    @RestClient
+    KruizeClient kruizeClient;
+
+    private DatasourceListResponse mockDatasourceResponse;
+    private DatasourceListResponse emptyDatasourceResponse;
+
+    @BeforeEach
+    void setUp() throws IOException {
+        Mockito.reset(bulkSchedulerService, kruizeStateService, kruizeClient);
+
+        // Mock the initialization to prevent startup from connecting to real Kruize
+        doNothing().when(bulkSchedulerService).initialize();
+        doNothing().when(kruizeStateService).refreshStateAndInstallProfiles();
+
+        // Load mock responses from JSON files
+        mockDatasourceResponse = MockResponseLoader.loadMockResponse("datasource_list.json", DatasourceListResponse.class);
+        emptyDatasourceResponse = MockResponseLoader.loadMockResponse("empty_datasource_list.json", DatasourceListResponse.class);
+    }
+
+    /**
+     * Test successful retrieval of datasources list
+     *
+     * Test Description: Verifies that the datasources list endpoint returns all available
+     * datasources when Kruize service has datasources configured.
+     *
+     * Mock Response (from datasource_list.json):
+     * - Contains 1 datasource: prometheus-1
+     *
+     * Expected Output:
+     * - HTTP Status: 200 OK
+     * - Response body contains:
+     *   - status: "success"
+     *   - message: "Datasources fetched successfully"
+     *   - data: Array with 1 datasource
+     *     - name: "prometheus-1"
+     *     - provider: "prometheus"
+     *     - url: "http://prometheus-k8s.monitoring.svc.cluster.local:9090"
+     */
+    @Test
+    void testListDatasources_Success() {
+        // Arrange - Mock KruizeClient to return the JSON response
+        when(kruizeClient.getDatasources()).thenReturn(mockDatasourceResponse);
+
+        // Act & Assert
+        given()
+            .when()
+            .get("/kruize/datasources/list")
+            .then()
+            .statusCode(200)
+            .contentType(ContentType.JSON)
+            .body("status", equalTo("success"))
+            .body("message", equalTo("Datasources fetched successfully"))
+            .body("data", hasSize(1))
+            .body("data[0].name", equalTo("prometheus-1"))
+            .body("data[0].provider", equalTo("prometheus"))
+            .body("data[0].url", equalTo("http://prometheus-k8s.monitoring.svc.cluster.local:9090"));
+
+        verify(kruizeClient, times(1)).getDatasources();
+    }
+
+    /**
+     * Test datasources list endpoint when no datasources are found
+     *
+     * Test Description: Verifies that when Kruize returns an empty datasources list,
+     * the optimizer service handles it gracefully and returns an appropriate message.
+     *
+     * Mock Response (from empty_datasource_list.json):
+     * - Kruize returns: {"version": "v1.0", "datasources": []}
+     *
+     * Expected Output:
+     * - HTTP Status: 200 OK
+     * - Response body contains:
+     *   - status: "success"
+     *   - message: "No datasources found"
+     *   - data: Empty array []
+     */
+    @Test
+    void testListDatasources_EmptyList() {
+        // Arrange - Mock KruizeClient to return empty list
+        when(kruizeClient.getDatasources()).thenReturn(emptyDatasourceResponse);
+
+        // Act & Assert
+        given()
+            .when()
+            .get("/kruize/datasources/list")
+            .then()
+            .statusCode(200)
+            .contentType(ContentType.JSON)
+            .body("status", equalTo("success"))
+            .body("message", equalTo("No datasources found"))
+            .body("data", hasSize(0));
+
+        verify(kruizeClient, times(1)).getDatasources();
+    }
+
+    /**
+     * Test datasources list endpoint when service throws an exception
+     *
+     * Test Description: Verifies that when the Kruize service throws an unexpected exception,
+     * the optimizer service returns a proper error response.
+     *
+     * Expected Output:
+     * - HTTP Status: 500 Internal Server Error
+     * - Response body contains:
+     *   - status: "error"
+     *   - message: Contains "Error fetching datasources"
+     */
+    @Test
+    void testListDatasources_ServiceException() {
+        // Arrange - Mock KruizeClient to throw exception
+        when(kruizeClient.getDatasources()).thenThrow(new RuntimeException("Service error"));
+
+        // Act & Assert
+        given()
+            .when()
+            .get("/kruize/datasources/list")
+            .then()
+            .statusCode(500)
+            .contentType(ContentType.JSON)
+            .body("status", equalTo("error"))
+            .body("message", containsString("Error fetching datasources"));
+
+        verify(kruizeClient, times(1)).getDatasources();
+    }
+
+    /**
+     * Test datasources list response structure
+     *
+     * Test Description: Verifies that the response from the datasources list endpoint
+     * contains all required fields with proper structure.
+     *
+     * Expected Output:
+     * - HTTP Status: 200 OK
+     * - Response body must contain keys: status, message, data
+     * - All fields must be non-null
+     */
+    @Test
+    void testListDatasources_VerifyResponseStructure() {
+        // Arrange
+        when(kruizeClient.getDatasources()).thenReturn(mockDatasourceResponse);
+
+        // Act & Assert
+        given()
+            .when()
+            .get("/kruize/datasources/list")
+            .then()
+            .statusCode(200)
+            .contentType(ContentType.JSON)
+            .body("$", hasKey("status"))
+            .body("$", hasKey("message"))
+            .body("$", hasKey("data"))
+            .body("status", notNullValue())
+            .body("message", notNullValue())
+            .body("data", notNullValue());
+
+        verify(kruizeClient, times(1)).getDatasources();
+    }
+}
+