Merge pull request #1438 from sass/extend-bugs

Fix a couple bugs with @extend

CHANGELOG.md

@@ -13,6 +13,9 @@
 
 * Properly parse backslash escapes within `url()` expressions.
 
+* Fix a couple bugs where `@extend`s could be marked as unsatisfied when
+  multiple identical `@extend`s extended selectors across `@use` rules.
+
 ### Command Line Interface
 
 * Strip CRLF newlines from snippets of the original stylesheet that are included

lib/src/extend/extension_store.dart

@@ -409,7 +409,7 @@ class ExtensionStore {
   /// Extends [this] with all the extensions in [extensions].
   ///
   /// These extensions will extend all selectors already in [this], but they
-  /// will *not* extend other extensions from [extenders].
+  /// will *not* extend other extensions from [extensionStores].
   void addExtensions(Iterable<ExtensionStore> extensionStores) {
     // Extensions already in [this] whose extenders are extended by
     // [extensions], and thus which need to be updated.
@@ -445,21 +445,18 @@ class ExtensionStore {
         // Add [newSources] to [_extensions].
         var existingSources = _extensions[target];
         if (existingSources == null) {
-          _extensions[target] = newSources;
+          _extensions[target] = Map.of(newSources);
           if (extensionsForTarget != null || selectorsForTarget != null) {
-            (newExtensions ??= {})[target] = newSources;
+            (newExtensions ??= {})[target] = Map.of(newSources);
           }
         } else {
           newSources.forEach((extender, extension) {
-            // If [extender] already extends [target] in [_extensions], we don't
-            // need to re-run the extension.
-            if (existingSources.containsKey(extender)) return;
-            existingSources[extender] = extension;
+            extension = existingSources.putOrMerge(
+                extender, extension, MergedExtension.merge);
 
             if (extensionsForTarget != null || selectorsForTarget != null) {
-              (newExtensions ??= {})
-                  .putIfAbsent(target, () => {})
-                  .putIfAbsent(extender, () => extension);
+              (newExtensions ??= {}).putIfAbsent(target, () => {})[extender] =
+                  extension;
             }
           });
         }

lib/src/node.dart

@@ -187,11 +187,11 @@ JsError _wrapException(Object exception) {
     var url = exception.span.sourceUrl;
     if (url == null) {
       file = 'stdin';
-  } else if (url.scheme == 'file') {
-    file = p.fromUri(url);
-  } else {
-    file = url.toString();
-  }
+    } else if (url.scheme == 'file') {
+      file = p.fromUri(url);
+    } else {
+      file = url.toString();
+    }
 
     return _newRenderError(exception.toString().replaceFirst("Error: ", ""),
         line: exception.span.start.line + 1,

lib/src/utils.dart

@@ -403,3 +403,15 @@ extension SpanExtensions on FileSpan {
         : file.span(this.start.offset + start, this.start.offset + end + 1);
   }
 }
+
+extension MapExtension<K, V> on Map<K, V> {
+  /// If [this] doesn't contain the given [key], sets that key to [value] and
+  /// returns it.
+  ///
+  /// Otherwise, calls [merge] with the existing value and [value] and sets
+  /// [key] to the result.
+  V putOrMerge(K key, V value, V Function(V oldValue, V newValue) merge) =>
+      containsKey(key)
+          ? this[key] = merge(this[key]!, value)
+          : this[key] = value;
+}

test/node_api/importer_test.dart

@@ -706,14 +706,14 @@ void main() {
     });
 
     test("it occurs in a file with a custom URL scheme", () {
-      var error =
-          renderSyncError(RenderOptions(
-              data: "@import 'foo:bar'",
-              importer: allowInterop(expectAsync2((String _, void __) {
-                  return NodeImporterResult(contents: '@error "oh no";');
+      var error = renderSyncError(RenderOptions(
+          data: "@import 'foo:bar'",
+          importer: allowInterop(expectAsync2((String _, void __) {
+            return NodeImporterResult(contents: '@error "oh no";');
           }))));
 
-          expect(error,
+      expect(
+          error,
           toStringAndMessageEqual("\"oh no\"\n"
               "  ╷\n"
               "1 │ @error \"oh no\";\n"