Handle redirects in Validator

Author: srawlins

lib/src/validator.dart

@@ -26,8 +26,12 @@ class Validator {
 
   final Map<String, Set<ModelElement>> _hrefs;
 
+  /// The set of files that have already been visited.
   final Set<String> _visited = {};
 
+  /// The set of files that simply redirect to a different file.
+  final Set<String> _redirects = {};
+
   Validator(this._packageGraph, this._config, String origin, this._writtenFiles,
       this._onCheckProgress)
       : _origin = path.normalize(origin),
@@ -60,8 +64,11 @@ class Validator {
       _visited.remove(fullPath);
       return;
     }
+    var _PageData(:links, :baseHref, :isRedirect) = pageLinks;
     _visited.add(fullPath);
-    var (links, baseHref) = pageLinks;
+    if (isRedirect) {
+      _redirects.add(fullPath);
+    }
 
     // Prevent extremely large stacks by storing the paths we are using
     // here instead -- occasionally, very large jobs have overflowed
@@ -166,7 +173,7 @@ class Validator {
         found.add(href);
       }
     }
-    final missingFromSearch = _visited.difference(found);
+    final missingFromSearch = _visited.difference(_redirects).difference(found);
     for (final missingFile in missingFromSearch) {
       _warn(PackageWarning.missingFromSearchIndex, missingFile, _origin,
           referredFrom: fullPath);
@@ -178,7 +185,7 @@ class Validator {
   ///
   /// This is extracted to save memory during the check; be careful not to hang
   /// on to anything referencing the full file and doc tree.
-  (Set<String> links, String? baseHref)? _getLinksAndBaseHref(String fullPath) {
+  _PageData? _getLinksAndBaseHref(String fullPath) {
     final file = _config.resourceProvider.getFile(fullPath);
     if (!file.exists) {
       return null;
@@ -209,8 +216,17 @@ class Validator {
                 ? path.url.join(uri, 'index.html')
                 : uri)
         .toSet();
+    var refreshTag = doc
+        .querySelectorAll('meta')
+        .firstWhereOrNull((e) => e.attributes['http-equiv'] == 'refresh');
+    if (refreshTag != null) {
+      var refreshUrl = refreshTag.attributes['url'];
+      if (refreshUrl != null) {
+        stringLinks.add(refreshUrl);
+      }
+    }
 
-    return (stringLinks, baseHref);
+    return _PageData(stringLinks, baseHref, refreshTag != null);
   }
 
   /// Warns on erroneous file paths.
@@ -252,3 +268,12 @@ class Validator {
         message: message, referredFrom: referredFromElements);
   }
 }
+
+/// Various data found in a given generate page
+class _PageData {
+  final Set<String> links;
+  final String? baseHref;
+  final bool isRedirect;
+
+  const _PageData(this.links, this.baseHref, this.isRedirect);
+}