Properly parse CR, CR LF, and FF as newlines everywhere (#626)

Closes #623

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 1.17.4
+
+* Consistently parse U+000C FORM FEED, U+000D CARRIAGE RETURN, and sequences of
+  U+000D CARRIAGE RETURN followed by U+000A LINE FEED as individual newlines.
+
 ## 1.17.3
 
 * Fix an edge case where slash-separated numbers were written to the stylesheet

lib/src/parse/sass.dart

@@ -155,6 +155,7 @@ class SassParser extends StylesheetParser {
       // Ignore empty lines.
       case $cr:
       case $lf:
+      case $ff:
         return null;
 
       case $dollar:
@@ -282,8 +283,8 @@ class SassParser extends StylesheetParser {
       if (_peekIndentation() <= parentIndentation) break;
 
       // Preserve empty lines.
-      while (isNewline(scanner.peekChar(1))) {
-        scanner.readChar();
+      while (_lookingAtDoubleNewline()) {
+        _expectNewline();
         buffer.writeln();
         buffer.write(" *");
       }
@@ -315,14 +316,34 @@ class SassParser extends StylesheetParser {
       case $semicolon:
         scanner.error("semicolons aren't allowed in the indented syntax.");
         return;
+      case $cr:
+        scanner.readChar();
+        if (scanner.peekChar() == $lf) scanner.readChar();
+        return;
       case $lf:
+      case $ff:
         scanner.readChar();
         return;
       default:
         scanner.error("expected newline.");
     }
   }
 
+  /// Returns whether the scanner is immediately before *two* newlines.
+  bool _lookingAtDoubleNewline() {
+    switch (scanner.peekChar()) {
+      case $cr:
+        var nextChar = scanner.peekChar(1);
+        if (nextChar == $lf) return isNewline(scanner.peekChar(2));
+        return nextChar == $cr || nextChar == $ff;
+      case $lf:
+      case $ff:
+        return isNewline(scanner.peekChar(1));
+      default:
+        return false;
+    }
+  }
+
   /// As long as the scanner's position is indented beneath the starting line,
   /// runs [body] to consume the next statement.
   void _whileIndentedLower(void body()) {

lib/src/parse/scss.dart

@@ -184,6 +184,16 @@ class ScssParser extends StylesheetParser {
           buffer.writeCharCode(scanner.readChar());
           return LoudComment(buffer.interpolation(scanner.spanFrom(start)));
 
+        case $cr:
+          scanner.readChar();
+          if (scanner.peekChar() != $lf) buffer.writeCharCode($lf);
+          break;
+
+        case $ff:
+          scanner.readChar();
+          buffer.writeCharCode($lf);
+          break;
+
         default:
           buffer.writeCharCode(scanner.readChar());
           break;

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass
-version: 1.17.3
+version: 1.17.4-dev
 description: A Sass implementation in Dart.
 author: Dart Team <[email protected]>
 homepage: https://github.com/sass/dart-sass

test/output_test.dart

@@ -0,0 +1,26 @@
+// Copyright 2019 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+// Almost all CSS output tests should go in sass-spec rather than here. This
+// just covers tests that explicitly validate out that's considered too
+// implementation-specific to verify in sass-spec.
+
+import 'package:test/test.dart';
+
+import 'package:sass/sass.dart';
+
+void main() {
+  // Regression test for sass/dart-sass#623. This needs to be tested here
+  // because sass-spec normalizes CR LF newlines.
+  group("normalizes newlines in a loud comment", () {
+    test("in SCSS", () {
+      expect(compileString("/* foo\r\n * bar */"), equals("/* foo\n * bar */"));
+    });
+
+    test("in Sass", () {
+      expect(compileString("/*\r\n  foo\r\n  bar", syntax: Syntax.sass),
+          equals("/* foo\n * bar */"));
+    });
+  });
+}