Migrator: Fix 'Report a Problem' link

Fixes https://github.com/dart-lang/sdk/issues/41485

Change-Id: I514cc299f7a821f8cd8d623a8d9702e694178379
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/146461
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Mike Fairhurst <mfairhurst@google.com>

pkg/nnbd_migration/lib/src/front_end/resources/index.html

@@ -71,7 +71,7 @@
       href="https://goo.gle/dart-null-safety-migration-tool">Null safety
         migration help</a>
     <span class="wide"> </span>
-    <div>Based on {{ sdkVersion }}</div>
+    <div>Based on <span id="sdk-version">{{ sdkVersion }}</span></div>
     <button class="report-problem">Report a Problem</button>
 </footer>
 </body>

pkg/nnbd_migration/lib/src/front_end/web/migration.dart

@@ -61,8 +61,7 @@ void main() {
 
     final reportProblemButton = document.querySelector('.report-problem');
     reportProblemButton.onClick.listen((_) {
-      window.open('https://goo.gle/dart-null-safety-migration-tool-issue',
-          'report-problem');
+      window.open(getGitHubProblemUri().toString(), 'report-problem');
     });
 
     document.querySelector('.popup-pane .close').onClick.listen(
@@ -106,6 +105,8 @@ final Element unitName = document.querySelector('#unit-name');
 
 String get rootPath => querySelector('.root').text.trim();
 
+String get sdkVersion => document.getElementById('sdk-version').text;
+
 void addArrowClickHandler(Element arrow) {
   var childList = (arrow.parentNode as Element).querySelector(':scope > ul');
   // Animating height from "auto" to "0" is not supported by CSS [1], so all we
@@ -187,7 +188,11 @@ Future<Map<String, Object>> doPost(String path) async {
   }
 }
 
-Uri getGithubUri(String description, Object exception, Object stackTrace) =>
+/// Returns the URL of the "new issue" form for the SDK repository,
+/// pre-populating the title, some labels, using [description], [exception], and
+/// [stackTrace] in the body.
+Uri getGitHubErrorUri(
+        String description, Object exception, Object stackTrace) =>
     Uri.https('github.com', 'dart-lang/sdk/issues/new', {
       'title': 'Issue with NNBD migration tool: $description',
       'labels': 'area-analyzer,analyzer-nnbd-migration,type-bug',
@@ -202,7 +207,7 @@ Please fill in the following:
 **What I was doing when this issue occurred**:
 **Is it possible to work around this issue**:
 **Has this issue happened before, and if so, how often**:
-**Dart SDK version**: (visible in lower left of migration preview)
+**Dart SDK version**: $sdkVersion
 **Additional details**:
 
 Thanks for filing!
@@ -215,6 +220,26 @@ $stackTrace
 ''',
     });
 
+/// Returns the URL of the "new issue" form for the SDK repository,
+/// pre-populating some labels and a body template.
+Uri getGitHubProblemUri() =>
+    Uri.https('github.com', 'dart-lang/sdk/issues/new', {
+      'labels': 'area-analyzer,analyzer-nnbd-migration,type-bug',
+      'body': '''
+#### Steps to reproduce
+
+#### What did you expect to happen?
+
+#### What actually happened?
+
+_Screenshots are appreciated_
+
+**Dart SDK version**: $sdkVersion
+
+Thanks for filing!
+''',
+    });
+
 int getLine(String location) {
   var str = Uri.parse(location).queryParameters['line'];
   return str == null ? null : int.tryParse(str);
@@ -258,7 +283,7 @@ void handleError(String header, Object exception, Object stackTrace) {
   popupPane.querySelector('p').innerText = subheader;
   popupPane.querySelector('pre').innerText = stackTrace.toString();
   (popupPane.querySelector('a.bottom') as AnchorElement).href =
-      getGithubUri(header, subheader, stackTrace).toString();
+      getGitHubErrorUri(header, subheader, stackTrace).toString();
   popupPane..style.display = 'initial';
   logError('$header: $exception', stackTrace);
 }