feat(step): added new well known step to test it an element is present

CHANGELOG.md

@@ -2,6 +2,7 @@
 * Added retry logic to the Futter driver connect call to handle the seemingly random connection failures
 * Ensured `AttachScreenshotOnFailedStepHook` cannot throw an unhandled exception causing the test run to stop
 * Added new well known step `When I tap the back button` which finds and taps the default page back button
+* Added a new well known step `Then I expect the widget 'notification' to be present` which expects a widget with a given key to be present within 5 seconds
 * Updated Gherkin library version
 
 ## [1.1.7+2] - 07/01/2019

lib/src/flutter/flutter_test_configuration.dart

@@ -12,6 +12,8 @@ import 'package:flutter_gherkin/src/flutter/steps/when_tap_the_back_button_step.
 import 'package:flutter_driver/flutter_driver.dart';
 import 'package:gherkin/gherkin.dart';
 
+import 'steps/then_expect_widget_to_be_present_step.dart';
+
 class FlutterTestConfiguration extends TestConfiguration {
   String _observatoryDebuggerUri;
 
@@ -102,6 +104,7 @@ class FlutterTestConfiguration extends TestConfiguration {
         GivenOpenDrawer(),
         WhenPauseStep(),
         WhenFillFieldStep(),
+        ThenExpectWidgetToBePresent(),
         RestartAppStep()
       ]);
   }

lib/src/flutter/steps/then_expect_widget_to_be_present_step.dart

@@ -0,0 +1,28 @@
+import 'package:flutter_gherkin/src/flutter/flutter_world.dart';
+import 'package:flutter_gherkin/src/flutter/utils/driver_utils.dart';
+import 'package:flutter_driver/flutter_driver.dart';
+import 'package:gherkin/gherkin.dart';
+
+/// Expects a widget with the given key to be present within 5 seconds
+///
+/// Parameters:
+///   1 - {string} the control key
+///
+/// Examples:
+///
+///   `Then I expect the widget 'notification' to be present`
+///   `Then I expect the button 'save' to be present`
+class ThenExpectWidgetToBePresent extends When1WithWorld<String, FlutterWorld> {
+  @override
+  RegExp get pattern => RegExp(
+      r"I expect the [button|element|label|icon|field|text|widget] {string} to be present");
+
+  @override
+  Future<void> executeStep(String key) async {
+    await FlutterDriverUtils.isPresent(
+      find.byValueKey(key),
+      world.driver,
+      timeout: const Duration(seconds: 5),
+    );
+  }
+}

lib/src/flutter/steps/when_tap_the_back_button_step.dart

@@ -12,8 +12,7 @@ import 'package:gherkin/gherkin.dart';
 ///   `When I tap the back widget"`
 class WhenTapBackButtonWidget extends WhenWithWorld<FlutterWorld> {
   @override
-  RegExp get pattern =>
-      RegExp(r"I tap the back [button|element|widget]");
+  RegExp get pattern => RegExp(r"I tap the back [button|element|widget]");
 
   @override
   Future<void> executeStep() async {

test/flutter_configuration_test.dart

@@ -3,6 +3,7 @@ import 'package:flutter_gherkin/src/flutter/hooks/app_runner_hook.dart';
 import 'package:flutter_gherkin/src/flutter/steps/given_i_open_the_drawer_step.dart';
 import 'package:flutter_gherkin/src/flutter/steps/restart_app_step.dart';
 import 'package:flutter_gherkin/src/flutter/steps/then_expect_element_to_have_value_step.dart';
+import 'package:flutter_gherkin/src/flutter/steps/then_expect_widget_to_be_present_step.dart';
 import 'package:flutter_gherkin/src/flutter/steps/when_fill_field_step.dart';
 import 'package:flutter_gherkin/src/flutter/steps/when_pause_step.dart';
 import 'package:flutter_gherkin/src/flutter/steps/when_tap_the_back_button_step.dart';
@@ -29,17 +30,20 @@ void main() {
 
         config.prepare();
         expect(config.stepDefinitions, isNotNull);
-        expect(config.stepDefinitions.length, 7);
+        expect(config.stepDefinitions.length, 8);
         expect(config.stepDefinitions.elementAt(0),
             (x) => x is ThenExpectElementToHaveValue);
         expect(config.stepDefinitions.elementAt(1), (x) => x is WhenTapWidget);
-        expect(config.stepDefinitions.elementAt(2), (x) => x is WhenTapBackButtonWidget);
+        expect(config.stepDefinitions.elementAt(2),
+            (x) => x is WhenTapBackButtonWidget);
         expect(
             config.stepDefinitions.elementAt(3), (x) => x is GivenOpenDrawer);
         expect(config.stepDefinitions.elementAt(4), (x) => x is WhenPauseStep);
         expect(
             config.stepDefinitions.elementAt(5), (x) => x is WhenFillFieldStep);
-        expect(config.stepDefinitions.elementAt(6), (x) => x is RestartAppStep);
+        expect(config.stepDefinitions.elementAt(6),
+            (x) => x is ThenExpectWidgetToBePresent);
+        expect(config.stepDefinitions.elementAt(7), (x) => x is RestartAppStep);
       });
 
       test("common step definition added to existing steps", () {
@@ -49,7 +53,7 @@ void main() {
 
         config.prepare();
         expect(config.stepDefinitions, isNotNull);
-        expect(config.stepDefinitions.length, 8);
+        expect(config.stepDefinitions.length, 9);
         expect(config.stepDefinitions.elementAt(0),
             (x) => x is MockStepDefinition);
         expect(config.stepDefinitions.elementAt(1),