[Sass] Only display text on the current line when reporting css2sass …

…errors.

doc-src/SASS_CHANGELOG.md

@@ -16,10 +16,14 @@ In addition, when the `sass` executable encounters an error,
 it now prints the filename where the error occurs,
 as well as a backtrace of Sass imports.
 
-### Minor Changes
+### `css2sass` Error Handling
 
-* `css2sass` error handling and reporting has been improved,
-  including fixing line-number reporting for templates without trailing newlines.
+Several bug fixes and minor improvements have been made, including:
+
+* Fixing line-number reporting for errors on the last line of templates
+  that didn't have trailing newlines.
+
+* Only displaying the text for the current line when reporting CSS parsing errors.
 
 ## [2.2.4](http://github.com/nex3/haml/commit/2.2.4)
 

lib/sass/css.rb

@@ -201,13 +201,13 @@ def assert_match(re)
 
       pos = @template.pos
 
-      after = @template.string[pos - 15...pos]
+      after = @template.string[[pos - 15, 0].max...pos].gsub(/.*\n/m, '')
       after = "..." + after if pos >= 15
 
       # Display basic regexps as plain old strings
       expected = re.source == Regexp.escape(re.source) ? "\"#{re.source}\"" : re.inspect
 
-      was = @template.rest[0...15]
+      was = @template.rest[0...15].gsub(/\n.*/m, '')
       was += "..." if @template.rest.size >= 15
       raise Sass::SyntaxError.new(
         "Invalid CSS after #{after.inspect}: expected #{expected}, was #{was.inspect}")

test/sass/css2sass_test.rb

@@ -235,15 +235,31 @@ def test_error_reporting
     assert(false, "Expected exception")
   rescue Sass::SyntaxError => err
     assert_equal(1, err.sass_line)
-    assert_equal('Invalid CSS after nil: expected /\{/, was ""', err.message)
+    assert_equal('Invalid CSS after "foo": expected /\{/, was ""', err.message)
   end
 
   def test_error_reporting_in_line
-    css2sass("foo\nbar }")
+    css2sass("foo\nbar }\nbaz")
     assert(false, "Expected exception")
   rescue Sass::SyntaxError => err
     assert_equal(2, err.sass_line)
-    assert_equal('Invalid CSS after "o\nbar ": expected /\{/, was "}"', err.message)
+    assert_equal('Invalid CSS after "bar ": expected /\{/, was "}"', err.message)
+  end
+
+  def test_error_truncate_after
+    css2sass("#{"a" * 15}foo")
+    assert(false, "Expected exception")
+  rescue Sass::SyntaxError => err
+    assert_equal(1, err.sass_line)
+    assert_equal('Invalid CSS after "...aaaaaaaaaaaafoo": expected /\{/, was ""', err.message)
+  end
+
+  def test_error_truncate_was
+    css2sass("foo }#{"a" * 15}")
+    assert(false, "Expected exception")
+  rescue Sass::SyntaxError => err
+    assert_equal(1, err.sass_line)
+    assert_equal('Invalid CSS after "foo ": expected /\{/, was "}aaaaaaaaaaaaaa..."', err.message)
   end
 
   private