Test invalid post IDs

Author: mathare

src/test/java/com/typicode/jsonplaceholder/features/Posts.feature

@@ -39,3 +39,12 @@ Feature: Posts Endpoint
     """
     And the "userId" field in the response body has a value of 1
 
+  Scenario Outline: Get post with invalid ID - post #<ID>
+    When I make a GET request to the Posts endpoint with a path parameter of <ID>
+    Then the response has a status code of 404
+    And the response body is an empty JSON object
+    Examples:
+      | ID  |
+      | 0   |
+      | 101 |
+      | -1  |

src/test/java/com/typicode/jsonplaceholder/steps/CommonSteps.java

@@ -57,7 +57,7 @@ public static void makeGetRequest(String endpoint) {
         response = RequestHelpers.sendGetRequestTo(endpoints.get(endpoint));
         responses.add(response);
     }
-    @When("^I make a GET request to the (Posts|Comments|Albums|Photos|ToDos|Users) endpoint with a path parameter of (\\d+)$")
+    @When("^I make a GET request to the (Posts|Comments|Albums|Photos|ToDos|Users) endpoint with a path parameter of (-?\\d+)$")
     public static void makeGetRequestWithPathParameter(String endpoint, int pathParam) {
         response = RequestHelpers.sendGetRequestTo(endpoints.get(endpoint) + "/" + pathParam);
         responses.add(response);
@@ -110,5 +110,10 @@ public static void verifyResponseBodyAgainstDataTable(DataTable dataTable) {
         expectedBody.forEach((k,v) -> assertEquals(expectedBody.get(k), actual.get(k).toString()));
     }
 
+    @Then("the response body is an empty JSON object")
+    public static void verifyResponseBodyIsEmptyJSONObject() {
+        assertEquals(new JSONObject().toString(), response.body());
+    }
+
 
 }