test: application must return OpenAPI specification JSON

src/test/java/systems/boos/traindelays/unit/OpenApiTest.java

@@ -0,0 +1,35 @@
+package systems.boos.traindelays.unit;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.test.web.server.LocalServerPort;
+
+import static org.hamcrest.Matchers.endsWith;
+import static org.hamcrest.Matchers.startsWith;
+import static org.junit.jupiter.api.Assertions.*;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+class OpenApiTest {
+    @LocalServerPort
+    private int port;
+
+    @Autowired
+    private TestRestTemplate restTemplate;
+
+    @Test
+    void contextLoads() {
+        assertTrue(true, "Spring application context must load.");
+    }
+
+    @Test
+    void getOpenApiJson__ReturnsValidOpenApiDescription() {
+        String response = this.restTemplate.getForObject("http://localhost:" + port + "/v3/api-docs", String.class);
+        assertThat(response, startsWith("{\"openapi\":\""));
+        assertThat(response, endsWith("}"));
+    }
+}