Fix a bug where a double-configuration error wouldn't be emitted

Closes #2598

Author: nex3

CHANGELOG.md

@@ -1,3 +1,10 @@
+## 1.90.0
+
+* **Potentially breaking bug fix:** Fix a situation where Sass wasn't emitting
+  an error when loading a `@forward`ed module with a configuration when that
+  module had already been loaded with a different configuration *and* all
+  configured variables in the new configuration had already been used.
+
 ## 1.89.2
 
 ### Embedded Host

lib/src/configuration.dart

@@ -50,7 +50,7 @@ final class Configuration {
   /// will be considered to have the same original config if they were created
   /// as a copy from the same base configuration.
   bool sameOriginal(Configuration that) =>
-      _originalConfiguration == that._originalConfiguration;
+      identical(_originalConfiguration, that._originalConfiguration);
 
   /// The empty configuration, which indicates that the module has not been
   /// configured.
@@ -70,7 +70,7 @@ final class Configuration {
 
   /// Creates a new configuration from this one based on a `@forward` rule.
   Configuration throughForward(ForwardRule forward) {
-    if (isEmpty) return const Configuration.empty();
+    if (isEmpty) return this;
     var newValues = _values;
 
     // Only allow variables that are visible through the `@forward` to be

lib/src/module.dart

@@ -30,8 +30,7 @@ abstract interface class Module<T extends AsyncCallable> {
   /// [AstNode.span] if the span isn't required, since some nodes need to do
   /// real work to manufacture a source span.
   ///
-  /// Implementations must ensure that this has the same keys as [variables] if
-  /// it's not `null`.
+  /// Implementations must ensure that this has the same keys as [variables].
   Map<String, AstNode> get variableNodes;
 
   /// The module's functions.

lib/src/visitor/async_evaluate.dart

@@ -854,8 +854,8 @@ final class _EvaluateVisitor
   }) async {
     var url = stylesheet.span.sourceUrl;
 
+    var currentConfiguration = configuration ?? _configuration;
     if (_modules[url] case var alreadyLoaded?) {
-      var currentConfiguration = configuration ?? _configuration;
       if (!_moduleConfigurations[url]!.sameOriginal(currentConfiguration) &&
           currentConfiguration is ExplicitConfiguration) {
         var message = namesInErrors
@@ -946,7 +946,7 @@ final class _EvaluateVisitor
     );
     if (url != null) {
       _modules[url] = module;
-      _moduleConfigurations[url] = _configuration;
+      _moduleConfigurations[url] = currentConfiguration;
       if (nodeWithSpan != null) _moduleNodes[url] = nodeWithSpan;
     }
 

lib/src/visitor/evaluate.dart

@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_evaluate.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: a3068d04660dd2bed34b884aa6e1a21d423dc4e5
+// Checksum: 30755d20ab8cdb065eb2c24d27a5f8a248591fcd
 //
 // ignore_for_file: unused_import
 
@@ -862,8 +862,8 @@ final class _EvaluateVisitor
   }) {
     var url = stylesheet.span.sourceUrl;
 
+    var currentConfiguration = configuration ?? _configuration;
     if (_modules[url] case var alreadyLoaded?) {
-      var currentConfiguration = configuration ?? _configuration;
       if (!_moduleConfigurations[url]!.sameOriginal(currentConfiguration) &&
           currentConfiguration is ExplicitConfiguration) {
         var message = namesInErrors
@@ -954,7 +954,7 @@ final class _EvaluateVisitor
     );
     if (url != null) {
       _modules[url] = module;
-      _moduleConfigurations[url] = _configuration;
+      _moduleConfigurations[url] = currentConfiguration;
       if (nodeWithSpan != null) _moduleNodes[url] = nodeWithSpan;
     }
 

pkg/sass-parser/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.4.25
+
+* No user-visible changes.
+
 ## 0.4.24
 
 * No user-visible changes.

pkg/sass-parser/package.json

@@ -1,6 +1,6 @@
 {
   "name": "sass-parser",
-  "version": "0.4.24",
+  "version": "0.4.25",
   "description": "A PostCSS-compatible wrapper of the official Sass parser",
   "repository": "sass/sass",
   "author": "Google Inc.",

pkg/sass_api/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 15.8.0
+
+* No user-visible changes.
+
 ## 15.7.1
 
 * No user-visible changes.

pkg/sass_api/pubspec.yaml

@@ -2,15 +2,15 @@ name: sass_api
 # Note: Every time we add a new Sass AST node, we need to bump the *major*
 # version because it's a breaking change for anyone who's implementing the
 # visitor interface(s).
-version: 15.7.1
+version: 15.8.0
 description: Additional APIs for Dart Sass.
 homepage: https://github.com/sass/dart-sass
 
 environment:
   sdk: ">=3.6.0 <4.0.0"
 
 dependencies:
-  sass: 1.89.2
+  sass: 1.90.0
 
 dev_dependencies:
   dartdoc: ^8.0.14

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass
-version: 1.89.2
+version: 1.90.0
 description: A Sass implementation in Dart.
 homepage: https://github.com/sass/dart-sass