Add rest-client-test module: @RestClientTest on Boot 4.1, Jackson 3 by default, and the RestClient-vs-RestTemplate root-URI matching trap (post #49)

2026-10-08 16:40:51 +00:00
parent 4370ac7fdf
commit b9388053c4
23 changed files with 704 additions and 0 deletions
@@ -0,0 +1,62 @@
+package com.ankurm.restclienttest;
+
+import tools.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.restclient.test.autoconfigure.RestClientTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.web.client.MockRestServiceServer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo;
+import static org.springframework.test.web.client.response.MockRestResponseCreators.withSuccess;
+
+/**
+ * The core example: a {@code RestClient}-based client, tested with {@code @RestClientTest} and
+ * {@code MockRestServiceServer}. {@link EmployeeClient} also depends on
+ * {@link EmployeeAuditLogger}, a plain collaborator the REST-client slice never creates on its
+ * own - replaced here with {@code @MockitoBean} now that {@code @MockBean} no longer exists in
+ * Spring Boot 4.
+ */
+@RestClientTest(EmployeeClient.class)
+class RestClientEmployeeTest {
+
+    @Autowired
+    private MockRestServiceServer mockServer;
+
+    @Autowired
+    private EmployeeClient employeeClient;
+
+    @Autowired
+    private ObjectMapper objectMapper;
+
+    @MockitoBean
+    private EmployeeAuditLogger auditLogger;
+
+    @Test
+    void whenGetEmployeeById_thenReturnsEmployeeAndAudits() throws Exception {
+        Employee mockEmployee = new Employee(1, "Ankur", "M", "[email protected]");
+        String employeeJson = objectMapper.writeValueAsString(mockEmployee);
+
+        mockServer.expect(requestTo("http://hr-api.example.com/employees/1"))
+                .andRespond(withSuccess(employeeJson, MediaType.APPLICATION_JSON));
+
+        Employee result = employeeClient.getEmployeeById(1);
+
+        assertThat(result).isNotNull();
+        assertThat(result.id()).isEqualTo(1);
+        assertThat(result.firstName()).isEqualTo("Ankur");
+
+        mockServer.verify();
+        Mockito.verify(auditLogger).logFetch(1);
+
+        Capture.write("01-restclient-basic-fetch.txt",
+                "RestClient-based EmployeeClient, real deserialized result and audit call",
+                "requestTo(\"http://hr-api.example.com/employees/1\") -> 200 OK " + employeeJson
+                        + "\nresult = " + result
+                        + "\nauditLogger.logFetch(1) called = " + Mockito.mockingDetails(auditLogger)
+                        .getInvocations().stream().anyMatch(i -> i.getMethod().getName().equals("logFetch")));
+    }
+}