NPE Fix: Return Empty List

src/main/java/com/amadeus/resources/Resource.java

@@ -3,6 +3,8 @@
 import com.amadeus.Response;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
 import lombok.Getter;
 
 /**
@@ -28,7 +30,11 @@ protected Resource() {}
    */
   public static Resource[] fromArray(Response response, Class klass) {
     Gson gson = new GsonBuilder().setDateFormat("yyyy-MM-dd").create();
-    Resource[] resources = (Resource[]) gson.fromJson(response.getData(), klass);
+    JsonElement responseData = response.getData();
+    if (responseData == null) {
+      responseData = new JsonArray(0);
+    }
+    Resource[] resources = (Resource[]) gson.fromJson(responseData, klass);
     for (Resource resource : resources) {
       resource.response = response;
       resource.deSerializationClass = klass;

src/test/java/com/amadeus/referenceData/locations/CitiesIT.java

@@ -1,10 +1,13 @@
 package com.amadeus.referencedata.locations;
 
 import static com.github.tomakehurst.wiremock.client.WireMock.aResponse;
+import static com.github.tomakehurst.wiremock.client.WireMock.equalTo;
 import static com.github.tomakehurst.wiremock.client.WireMock.get;
 import static com.github.tomakehurst.wiremock.client.WireMock.post;
 import static com.github.tomakehurst.wiremock.client.WireMock.urlEqualTo;
+import static com.github.tomakehurst.wiremock.client.WireMock.urlPathEqualTo;
 import static org.assertj.core.api.AssertionsForClassTypes.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 
 import com.amadeus.Amadeus;
@@ -74,6 +77,27 @@ public void givenClientWhenCallCitySearchWithParamsThenOK()
     assertNotEquals(0, result.length);
   }
 
+  @Test
+  public void givenClientWhenCallCitySearchWithParamsThenEmpty() throws ResponseException {
+
+    // Given
+    String address = "/v1/reference-data/locations/cities";
+    wireMockServer.stubFor(get(urlPathEqualTo(address))
+        .withQueryParam("keyword", equalTo("SANC"))
+        .withQueryParam("countryCode", equalTo("AZ"))
+        .willReturn(aResponse().withHeader("Content-Type", "application/json")
+        .withStatus(200)
+        .withBodyFile("city_search_response_empty.json")));
+
+    Params params = Params.with("keyword", "SANC").and("countryCode", "AZ");
+
+    // When
+    City[] result = amadeus.referenceData.locations.cities.get(params);
+
+    // Then
+    assertEquals(0, result.length);
+  }
+
   @Test
   public void givenClientWhenCallCitySearchWithoutParamsThenOK()
       throws ResponseException {

src/test/resources/__files/city_search_response_empty.json

@@ -0,0 +1,19 @@
+{
+  "warnings": [
+    {
+      "code": 1797,
+      "title": "DATA NOT FOUND",
+      "detail": "No Cities available",
+      "source": {
+        "parameter": "keyword"
+      },
+      "status": 200
+    }
+  ],
+  "meta": {
+    "count": 0,
+    "links": {
+      "self": "https://test.api.amadeus.com/v1/reference-data/locations/cities?countryCode=AZ&keyword=SANC&max=1000"
+    }
+  }
+}