Add test 404 for GetArticle route

src/test/kotlin/integration/Article routes.kt

@@ -22,6 +22,7 @@ import integration.steps.then.`which contains`
 import integration.steps.then.and
 import io.ktor.http.HttpStatusCode.Companion.BadRequest
 import io.ktor.http.HttpStatusCode.Companion.Forbidden
+import io.ktor.http.HttpStatusCode.Companion.NotFound
 import io.ktor.http.HttpStatusCode.Companion.OK
 import org.junit.jupiter.api.Tag
 import org.junit.jupiter.api.Tags
@@ -82,6 +83,17 @@ class `Article routes` : BaseTest() {
         }
     }
 
+    @Test
+    fun `I cannot get article with id doesn't exist`() {
+        withIntegrationApplication {
+            `When I send a GET request`("/articles/635fe2e8-2dbc-4c80-b306-101d38a4ab23") `Then the response should be` NotFound and {
+                `And the response should not be null`()
+                `And the response should contain`("$.title", "Article 635fe2e8-2dbc-4c80-b306-101d38a4ab23 not found")
+                `And the response should contain`("$.statusCode", 404)
+            }
+        }
+    }
+
     @Test
     @Tag("BadRequest")
     fun `I cannot get article by id with wrong id format`() {