Properly merge "all and" media queries

Closes #537

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 1.15.3
+
+* Properly merge `all and` media queries. These queries were previously being
+  merged as though `all` referred to a specific media type, rather than all
+  media types.
+
 ## 1.15.2
 
 ### Node JS API

lib/src/ast/css/media_query.dart

@@ -24,6 +24,9 @@ class CssMediaQuery {
   /// Whether this media query only specifies features.
   bool get isCondition => modifier == null && type == null;
 
+  /// Whether this media query matches all media types.
+  bool get matchesAllTypes => type == null || equalsIgnoreCase(type, 'all');
+
   /// Parses a media query from [contents].
   ///
   /// If passed, [url] is the name of the file from which [contents] comes.
@@ -77,7 +80,7 @@ class CssMediaQuery {
         } else {
           return MediaQueryMergeResult.unrepresentable;
         }
-      } else if (ourType == null || theirType == null) {
+      } else if (this.matchesAllTypes || other.matchesAllTypes) {
         return MediaQueryMergeResult.unrepresentable;
       }
 
@@ -112,11 +115,13 @@ class CssMediaQuery {
         // Otherwise, there's no way to represent the intersection.
         return MediaQueryMergeResult.unrepresentable;
       }
-    } else if (ourType == null) {
+    } else if (this.matchesAllTypes) {
       modifier = theirModifier;
-      type = theirType;
+      // Omit the type if either input query did, since that indicates that they
+      // aren't targeting a browser that requires "all and".
+      type = (other.matchesAllTypes && ourType == null) ? null : theirType;
       features = this.features.toList()..addAll(other.features);
-    } else if (theirType == null) {
+    } else if (other.matchesAllTypes) {
       modifier = ourModifier;
       type = ourType;
       features = this.features.toList()..addAll(other.features);

lib/src/utils.dart

@@ -233,7 +233,14 @@ bool equalsIgnoreCase(String string1, String string2) {
   if (identical(string1, string2)) return true;
   if (string1 == null || string2 == null) return false;
   if (string1.length != string2.length) return false;
-  return string1.toUpperCase() == string2.toUpperCase();
+
+  for (var i = 0; i < string1.length; i++) {
+    if (!characterEqualsIgnoreCase(
+            string1.codeUnitAt(i), string2.codeUnitAt(i))) {
+      return false;
+    }
+  }
+  return true;
 }
 
 /// Returns whether [string] starts with [prefix], ignoring ASCII case.

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass
-version: 1.15.2
+version: 1.15.3-dev
 description: A Sass implementation in Dart.
 author: Dart Team <[email protected]>
 homepage: https://github.com/sass/dart-sass