gigasecond: Revise exercise with updates to the specification

exercises/gigasecond/README.md

@@ -1,6 +1,7 @@
 # Gigasecond
 
-Calculate the moment when someone has lived for 10^9 seconds.
+Given a moment, determine the moment that would be after a gigasecond
+has passed.
 
 A gigasecond is 10^9 (1,000,000,000) seconds.
 

exercises/gigasecond/pubspec.yaml

@@ -1,4 +1,5 @@
 name: 'gigasecond'
+version: 2.0.0
 environment:
   sdk: '>=2.0.0 <3.0.0'
 dev_dependencies:

exercises/gigasecond/test/gigasecond_test.dart

@@ -1,48 +1,50 @@
-import 'package:test/test.dart';
 import 'package:gigasecond/gigasecond.dart';
+import 'package:test/test.dart';
 
 void main() {
   group("Gigasecond", gigasecondTests);
 }
 
 void gigasecondTests() {
-  test("date only specification of time", () {
-    final DateTime birthDate = new DateTime.utc(2011, DateTime.april, 25);
-    final DateTime result = add(birthDate);
-    DateTime expectedDate = new DateTime.utc(2043, DateTime.january, 1, 1, 46, 40);
-
-    expect(result, equals(expectedDate));
-  }, skip: false);
-
-  test("second test for date only specification of time", () {
-    final DateTime birthDate = new DateTime.utc(1977, DateTime.june, 13);
-    final DateTime result = add(birthDate);
-    DateTime expectedDate = new DateTime.utc(2009, DateTime.february, 19, 1, 46, 40);
-
-    expect(result, equals(expectedDate));
-  }, skip: true);
-
-  test("third test for date only specification of time", () {
-    final DateTime birthDate = new DateTime.utc(1959, DateTime.july, 19);
-    final DateTime result = add(birthDate);
-    DateTime expectedDate = new DateTime.utc(1991, DateTime.march, 27, 1, 46, 40);
-
-    expect(result, equals(expectedDate));
-  }, skip: true);
-
-  test("full time specified", () {
-    final DateTime birthDate = new DateTime.utc(2015, DateTime.january, 24, 22, 00, 00);
-    final DateTime result = add(birthDate);
-    DateTime expectedDate = new DateTime.utc(2046, DateTime.october, 2, 23, 46, 40);
-
-    expect(result, equals(expectedDate));
-  }, skip: true);
-
-  test("full time with day roll-over", () {
-    final DateTime birthDate = new DateTime.utc(2015, DateTime.january, 24, 23, 59, 59);
-    final DateTime result = add(birthDate);
-    DateTime expectedDate = new DateTime.utc(2046, DateTime.october, 3, 01, 46, 39);
-
-    expect(result, equals(expectedDate));
-  }, skip: true);
+  group('Add one gigasecond to the input. ', () {
+    test('date only specification of time', () {
+      final DateTime birthDate = new DateTime.utc(2011, DateTime.april, 25);
+      final DateTime result = add(birthDate);
+      DateTime expectedDate = new DateTime.utc(2043, DateTime.january, 1, 1, 46, 40);
+
+      expect(result, equals(expectedDate));
+    }, skip: false);
+
+    test('second test for date only specification of time', () {
+      final DateTime birthDate = new DateTime.utc(1977, DateTime.june, 13);
+      final DateTime result = add(birthDate);
+      DateTime expectedDate = new DateTime.utc(2009, DateTime.february, 19, 1, 46, 40);
+
+      expect(result, equals(expectedDate));
+    }, skip: true);
+
+    test('third test for date only specification of time', () {
+      final DateTime birthDate = new DateTime.utc(1959, DateTime.july, 19);
+      final DateTime result = add(birthDate);
+      DateTime expectedDate = new DateTime.utc(1991, DateTime.march, 27, 1, 46, 40);
+
+      expect(result, equals(expectedDate));
+    }, skip: true);
+
+    test('full time specified', () {
+      final DateTime birthDate = new DateTime.utc(2015, DateTime.january, 24, 22, 00, 00);
+      final DateTime result = add(birthDate);
+      DateTime expectedDate = new DateTime.utc(2046, DateTime.october, 2, 23, 46, 40);
+
+      expect(result, equals(expectedDate));
+    }, skip: true);
+
+    test('full time with day roll-over', () {
+      final DateTime birthDate = new DateTime.utc(2015, DateTime.january, 24, 23, 59, 59);
+      final DateTime result = add(birthDate);
+      DateTime expectedDate = new DateTime.utc(2046, DateTime.october, 3, 01, 46, 39);
+
+      expect(result, equals(expectedDate));
+    }, skip: true);
+  });
 }