add test to verify null param issue

Author: baev

allure-rest-assured/src/test/java/io/qameta/allure/restassured/AllureRestAssuredTest.java

@@ -36,6 +36,7 @@
 
 import java.nio.charset.StandardCharsets;
 import java.util.Collection;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
@@ -301,6 +302,33 @@ void shouldRenderListValuedFormParams() {
                 .contains("data=[a, b]");
     }
 
+    @Test
+    void shouldNotFailForNullValuedFormParamsMap() {
+        final ResponseDefinitionBuilder responseBuilder = WireMock.aResponse()
+                .withStatus(200)
+                .withBody("some body");
+
+        final Map<String, Object> formParams = new LinkedHashMap<>();
+        formParams.put("param1", "value1");
+        formParams.put("param2", null);
+
+        final AllureResults results = executeWithStub(
+                server -> WireMock.stubFor(WireMock.post(WireMock.urlPathEqualTo("/hello"))
+                        .willReturn(responseBuilder)),
+                server -> RestAssured.given()
+                        .contentType(ContentType.URLENC)
+                        .formParams(formParams)
+                        .post(server.url("/hello")).then().statusCode(200)
+        );
+
+        assertThat(results.getTestResults()
+                .stream()
+                .map(TestResult::getAttachments)
+                .flatMap(Collection::stream)
+                .map(Attachment::getName))
+                .containsExactly("Request", "HTTP/1.1 200 OK");
+    }
+
     protected final AllureResults executeWithStub(final Consumer<WireMockServer> stubSetup,
                                                   final Consumer<WireMockServer> requestExecutor) {
         return executeWithStub(stubSetup, requestExecutor, new AllureRestAssured());