Detect redirecting page in the dartdoc-generated output + render in-place. (#8342)

isoos · web-flow · commit b7816e5d5ce5 · 2024-11-28T18:59:40.000+01:00
diff --git a/app/lib/fake/backend/fake_pub_worker.dart b/app/lib/fake/backend/fake_pub_worker.dart
@@ -237,6 +237,7 @@ Map<String, String> _fakeDartdocFiles(
       usingBaseHref: null,
       aboveSidebarUrl: null,
       belowSidebarUrl: null,
+      redirectPath: null,
     ).toJson()),
     'index.json': '{}',
     'pub-data.json': json.encode(pubData),
@@ -251,6 +252,7 @@ Map<String, String> _fakeDartdocFiles(
       usingBaseHref: null,
       aboveSidebarUrl: null,
       belowSidebarUrl: null,
+      redirectPath: null,
     ).toJson()),
   };
 }
diff --git a/app/lib/task/handlers.dart b/app/lib/task/handlers.dart
@@ -1,6 +1,8 @@
 import 'dart:convert';
 import 'dart:io' show gzip;
 
+import 'package:path/path.dart' as p;
+
 import 'package:pub_dev/dartdoc/dartdoc_page.dart';
 import 'package:pub_dev/dartdoc/models.dart';
 import 'package:pub_dev/shared/exceptions.dart';
@@ -92,7 +94,29 @@ Future<shelf.Response> handleDartDoc(
               DartDocSidebar.fromJson(dataJson as Map<String, dynamic>);
           return utf8.encode(sidebar.content);
         }
-        final page = DartDocPage.fromJson(dataJson as Map<String, dynamic>);
+        var page = DartDocPage.fromJson(dataJson as Map<String, dynamic>);
+
+        // NOTE: If the loaded page is redirecting, we try to load it and render
+        //       the page it is pointing to. Instead, we should redirect the page
+        //       to the new URL.
+        // TODO: restructure cache logic and implement proper redirect
+        final redirectPath = page.redirectPath;
+        if (page.isEmpty() &&
+            redirectPath != null &&
+            p.isRelative(redirectPath)) {
+          final newPath = p.normalize(p.joinAll([
+            p.dirname(path),
+            redirectPath,
+            if (!redirectPath.endsWith('.html')) 'index.html',
+          ]));
+          final newDataGz =
+              await taskBackend.dartdocFile(package, version, newPath);
+          if (newDataGz != null) {
+            final newDataJson = gzippedUtf8JsonCodec.decode(newDataGz);
+            page = DartDocPage.fromJson(newDataJson as Map<String, dynamic>);
+          }
+        }
+
         final html = page.render(DartDocPageOptions(
           package: package,
           version: version,
diff --git a/app/test/dartdoc/dartdoc_page_test.dart b/app/test/dartdoc/dartdoc_page_test.dart
@@ -34,6 +34,24 @@ import '../shared/utils.dart';
 // we may need to update either the test or the rendering templates until
 // there are only known and accepted differences between the two.
 void main() {
+  group('DartDocPage parsing edge cases', () {
+    test('parse redirect URL', () {
+      final redirectContent = '''<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <link rel="canonical" href="../retry" />
+    <meta http-equiv="refresh" content="0; url=../retry" />
+  </head>
+  <body>
+    <p><a href="../retry">New URL</a></p>
+  </body>
+</html>''';
+      final page = DartDocPage.parse(redirectContent);
+      expect(page.isEmpty(), true);
+      expect(page.redirectPath, '../retry');
+    });
+  });
+
   group('DartDocPage rendering', () {
     final tempDir = Directory.systemTemp.createTempSync();
     final pkgDir = p.join(tempDir.path, 'pkg');
diff --git a/pkg/_pub_shared/lib/dartdoc/dartdoc_page.dart b/pkg/_pub_shared/lib/dartdoc/dartdoc_page.dart
@@ -89,6 +89,9 @@ final class DartDocPage {
   /// The right/below sidebar URL that dartdoc will load dynamically.
   final String? belowSidebarUrl;
 
+  /// The path URL this page redirects to.
+  final String? redirectPath;
+
   DartDocPage({
     required this.title,
     required this.description,
@@ -100,6 +103,7 @@ final class DartDocPage {
     required this.usingBaseHref,
     required this.aboveSidebarUrl,
     required this.belowSidebarUrl,
+    required this.redirectPath,
   });
 
   factory DartDocPage.fromJson(Map<String, dynamic> json) =>
@@ -126,6 +130,21 @@ final class DartDocPage {
         },
       );
 
+  /// Indicates that the [DartDocPage] was could not parse any displayable
+  /// content from the dartdoc output. Such page is a redirect page that was
+  /// introduced in `dartdoc 8.3.0`.
+  bool isEmpty() {
+    return title.isEmpty &&
+        description.isEmpty &&
+        breadcrumbs.isEmpty &&
+        left.isEmpty &&
+        right.isEmpty &&
+        (baseHref == null || baseHref!.isEmpty) &&
+        (usingBaseHref == null || usingBaseHref!.isEmpty) &&
+        (aboveSidebarUrl == null || aboveSidebarUrl!.isEmpty) &&
+        (belowSidebarUrl == null || belowSidebarUrl!.isEmpty);
+  }
+
   static DartDocPage parse(String rawHtml) {
     final document = html_parser.parse(rawHtml);
 
@@ -182,6 +201,17 @@ final class DartDocPage {
     }
     final content = rawContent?.innerHtml;
 
+    final httpEquivRefresh = document.head
+        ?.querySelectorAll('meta')
+        .where((e) => e.attributes['http-equiv'] == 'refresh')
+        .firstOrNull;
+    final redirectPath = httpEquivRefresh?.attributes['content']
+        ?.split(';')
+        .map((p) => p.trim())
+        .where((p) => p.startsWith('url='))
+        .firstOrNull
+        ?.substring(4);
+
     return DartDocPage(
       title: document.querySelector('head > title')?.text ?? '',
       description: document
@@ -196,6 +226,7 @@ final class DartDocPage {
       usingBaseHref: body?.attributes['data-using-base-href'],
       aboveSidebarUrl: rawContent?.attributes['data-above-sidebar'],
       belowSidebarUrl: rawContent?.attributes['data-below-sidebar'],
+      redirectPath: redirectPath,
     );
   }
 }
diff --git a/pkg/_pub_shared/lib/dartdoc/dartdoc_page.g.dart b/pkg/_pub_shared/lib/dartdoc/dartdoc_page.g.dart
