feat(steps): Added new well known step `When I tap the back button` which finds and taps the default page back button

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## [1.1.7+3] - 08/01/2019
 * 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
 
 ## [1.1.7+2] - 07/01/2019
 * Increased the Flutter driver reconnection delay to try and overcome some driver to app connection issues on slower machines

README.md

@@ -924,6 +924,7 @@ For convenience the library defines a number of pre-defined steps so you can get
 | I (open\|close) the drawer                              | Opens or closes the application default drawer    | `When I open the drawer`, `And I close the drawer`|
 | I pause for {int} seconds                               | Pauses the test execution for the given seconds. Only use in debug scenarios or to inspect the state of the app | `Then I pause for 20 seconds`                                 |
 | I restart the app                                       | Restarts the app under test | `Then I restart the app` |
+| I tap the back button                                   | Taps the page default back button widget | `Then I tap the back button` |
 
 #### Flutter Driver Utilities
 

lib/src/flutter/steps/when_tap_the_back_button_step.dart

@@ -0,0 +1,26 @@
+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';
+
+/// Taps the back button widget
+///
+/// Examples:
+///
+///   `When I tap the back button"`
+///   `When I tap the back element"`
+///   `When I tap the back widget"`
+class WhenTapWidget extends When1WithWorld<String, FlutterWorld> {
+  @override
+  RegExp get pattern =>
+      RegExp(r"I tap the back button [button|element|widget]");
+
+  @override
+  Future<void> executeStep(String key) async {
+    await FlutterDriverUtils.tap(
+      world.driver,
+      find.pageBack(),
+      timeout: timeout * .9,
+    );
+  }
+}

lib/src/flutter/steps/when_tap_widget_step.dart

@@ -24,7 +24,10 @@ class WhenTapWidget extends When1WithWorld<String, FlutterWorld> {
 
   @override
   Future<void> executeStep(String key) async {
-    await FlutterDriverUtils.tap(world.driver, find.byValueKey(key),
-        timeout: timeout * .9);
+    await FlutterDriverUtils.tap(
+      world.driver,
+      find.byValueKey(key),
+      timeout: timeout * .9,
+    );
   }
 }