feat: add share button for challenge links

mobile-app/lib/l10n/app_en.arb

@@ -671,6 +671,10 @@
     "@temporarily_unavailable": {
         "description": "snackbar shown when a curriculum item is temporarily disabled"
     },
+    "share_challenge": "Share this challenge",
+    "@share_challenge": {
+        "description": "tooltip for the button that shares a link to the current challenge"
+    },
     "not_available_web": "Not available use the web version",
     "@not_available_web": {
         "description": "snackbar shown when a curriculum item is only available on the web"

mobile-app/lib/l10n/app_es.arb

@@ -613,6 +613,7 @@
   "no_blocks_available": "No blocks available right now.",
   "coming_soon": "Coming Soon",
   "temporarily_unavailable": "Temporarily unavailable, come back soon.",
+  "share_challenge": "Share this challenge",
   "not_available_web": "Not available use the web version",
   "stage_core": "Recommended curriculum (still in beta):",
   "stage_english": "Learn English for Developers:",

mobile-app/lib/l10n/app_localizations.dart

@@ -1067,6 +1067,12 @@ abstract class AppLocalizations {
   /// **'Temporarily unavailable, come back soon.'**
   String get temporarily_unavailable;
 
+  /// tooltip for the button that shares a link to the current challenge
+  ///
+  /// In en, this message translates to:
+  /// **'Share this challenge'**
+  String get share_challenge;
+
   /// snackbar shown when a curriculum item is only available on the web
   ///
   /// In en, this message translates to:

mobile-app/lib/l10n/app_localizations_en.dart

@@ -576,6 +576,9 @@ class AppLocalizationsEn extends AppLocalizations {
   String get temporarily_unavailable =>
       'Temporarily unavailable, come back soon.';
 
+  @override
+  String get share_challenge => 'Share this challenge';
+
   @override
   String get not_available_web => 'Not available use the web version';
 

mobile-app/lib/l10n/app_localizations_es.dart

@@ -576,6 +576,9 @@ class AppLocalizationsEs extends AppLocalizations {
   String get temporarily_unavailable =>
       'Temporarily unavailable, come back soon.';
 
+  @override
+  String get share_challenge => 'Share this challenge';
+
   @override
   String get not_available_web => 'Not available use the web version';
 

mobile-app/lib/l10n/app_localizations_pt.dart

@@ -576,6 +576,9 @@ class AppLocalizationsPt extends AppLocalizations {
   String get temporarily_unavailable =>
       'Temporarily unavailable, come back soon.';
 
+  @override
+  String get share_challenge => 'Share this challenge';
+
   @override
   String get not_available_web => 'Not available use the web version';
 

mobile-app/lib/l10n/app_pt.arb

@@ -613,6 +613,7 @@
   "no_blocks_available": "No blocks available right now.",
   "coming_soon": "Coming Soon",
   "temporarily_unavailable": "Temporarily unavailable, come back soon.",
+  "share_challenge": "Share this challenge",
   "not_available_web": "Not available use the web version",
   "stage_core": "Recommended curriculum (still in beta):",
   "stage_english": "Learn English for Developers:",

mobile-app/lib/ui/views/learn/challenge/challenge_view.dart

@@ -7,10 +7,12 @@ import 'package:freecodecamp/models/learn/curriculum_model.dart';
 import 'package:freecodecamp/models/learn/daily_challenge_model.dart';
 import 'package:freecodecamp/ui/theme/fcc_theme.dart';
 import 'package:freecodecamp/ui/views/learn/challenge/challenge_viewmodel.dart';
+import 'package:freecodecamp/ui/views/learn/utils/challenge_utils.dart';
 import 'package:freecodecamp/ui/views/learn/widgets/challenge_widgets/project_preview.dart';
 import 'package:freecodecamp/ui/views/learn/widgets/challenge_widgets/symbol_bar.dart';
 import 'package:freecodecamp/ui/views/learn/widgets/console/console_view.dart';
 import 'package:freecodecamp/ui/views/news/html_handler/html_handler.dart';
+import 'package:share_plus/share_plus.dart';
 import 'package:stacked/stacked.dart';
 
 class ChallengeView extends StatelessWidget {
@@ -268,6 +270,7 @@ class ChallengeView extends StatelessWidget {
           Row(
             children: [
               ..._panelIconButtons(
+                context,
                 model,
                 challenge,
                 block,
@@ -485,6 +488,7 @@ class ChallengeView extends StatelessWidget {
     required bool isActive,
     required IconData icon,
     required VoidCallback? onPressed,
+    String? tooltip,
   }) {
     return Container(
       margin: const EdgeInsets.symmetric(horizontal: 8),
@@ -499,6 +503,7 @@ class ChallengeView extends StatelessWidget {
               : Colors.white,
         ),
         onPressed: onPressed,
+        tooltip: tooltip,
         splashColor: Colors.transparent,
         highlightColor: Colors.transparent,
       ),
@@ -547,6 +552,7 @@ class ChallengeView extends StatelessWidget {
   }
 
   List<Widget> _panelIconButtons(
+    BuildContext context,
     ChallengeViewModel model,
     Challenge challenge,
     Block block,
@@ -586,6 +592,19 @@ class ChallengeView extends StatelessWidget {
           model.setMounted = false;
         },
       ),
+      _panelIconButton(
+        isActive: false,
+        icon: Icons.share,
+        tooltip: context.t.share_challenge,
+        onPressed: () {
+          SharePlus.instance.share(
+            ShareParams(
+              text:
+                  '${block.name} - ${challenge.title}\n\n${challengeUrl(challenge)}',
+            ),
+          );
+        },
+      ),
     ];
   }
 

mobile-app/lib/ui/views/learn/utils/challenge_utils.dart

@@ -1,6 +1,12 @@
 import 'package:freecodecamp/models/learn/challenge_model.dart';
 import 'package:freecodecamp/models/learn/curriculum_model.dart';
 
+// Builds the public freeCodeCamp URL of a challenge, so campers can share the
+// exact step they are on.
+String challengeUrl(Challenge challenge) {
+  return 'https://www.freecodecamp.org/learn/${challenge.superBlock}/${challenge.block}/${challenge.dashedName}';
+}
+
 String handleChallengeTitle(Challenge challenge, Block block) {
   if (block.challenges.length == 1 ||
       challenge.title.contains('Dialogue') ||

mobile-app/lib/ui/views/learn/widgets/hint/hint_widget_view.dart

@@ -4,6 +4,7 @@ import 'package:freecodecamp/models/learn/challenge_model.dart';
 import 'package:freecodecamp/models/learn/curriculum_model.dart';
 import 'package:freecodecamp/service/learn/learn_service.dart';
 import 'package:freecodecamp/ui/views/learn/challenge/challenge_viewmodel.dart';
+import 'package:freecodecamp/ui/views/learn/utils/challenge_utils.dart';
 import 'package:freecodecamp/ui/views/learn/widgets/hint/hint_widget_model.dart';
 import 'package:freecodecamp/ui/views/news/html_handler/html_handler.dart';
 import 'package:freecodecamp/utils/helpers.dart';
@@ -26,7 +27,7 @@ Future<String> genForumLink(
   final titleText = '$blockTitle - ${currChallenge.title}';
   final t = context.t;
   final String endingText =
-      '**${t.forum_mobile_info}**\n```txt\n$userDeviceInfo\n```\n\n**${t.forum_challenge}** $titleText\n\n**${t.forum_challenge_link}**\nhttps://www.freecodecamp.org/learn/${currChallenge.superBlock}/${currChallenge.block}/${currChallenge.dashedName}';
+      '**${t.forum_mobile_info}**\n```txt\n$userDeviceInfo\n```\n\n**${t.forum_challenge}** $titleText\n\n**${t.forum_challenge_link}**\n${challengeUrl(currChallenge)}';
 
   final String userCode = await filesToMarkdown(currChallenge, editorText);
 

mobile-app/test/unit/challenge_utils_test.dart

@@ -40,6 +40,17 @@ void main() {
     );
   }
 
+  group('challengeUrl', () {
+    test('should build the public learn URL of a challenge', () {
+      final challenge = createChallenge(id: '1', title: 'Step 1');
+
+      expect(
+        challengeUrl(challenge),
+        'https://www.freecodecamp.org/learn/superblock/block1/challenge-1',
+      );
+    });
+  });
+
   group('handleChallengeTitle', () {
     test('should return empty string if the block contains a single challenge',
         () {