Remove magical selector reordering with @extend. Fixes #269.

Turns out the @extend rewrite was already doing the right thing; the
only things keeping this logic around were a couple old xCSS tests that
expected output in the wrong order.

5 files changed, 40 insertions, 23 deletions

diff --git a/scss/compiler.py b/scss/compiler.py
index 73fd84d..0d0a62f 100644
--- a/scss/compiler.py
+++ b/scss/compiler.py
@@ -1197,6 +1197,12 @@ class Compilation(object):
         # DEVIATION: ruby sass doesn't support bare variables in selectors
         raw_selectors = calculator.apply_vars(raw_selectors)
         c_selectors, c_parents = self.parse_selectors(raw_selectors)
+        if c_parents:
+            warn_deprecated(
+                rule,
+                "The XCSS 'a extends b' syntax is deprecated.  "
+                "Use 'a { @extend b; }' instead."
+            )
 
         new_ancestry = rule.ancestry.with_nested_selectors(c_selectors)
 
@@ -1236,19 +1242,7 @@ class Compilation(object):
         # them as a rough key.  Ignore order and duplication for now.
         key_to_selectors = defaultdict(set)
         selector_to_rules = defaultdict(list)
-        # DEVIATION: These are used to rearrange rules in dependency order, so
-        # an @extended parent appears in the output before a child.  Sass does
-        # not do this, and the results may be unexpected.  Pending removal.
-        rule_order = dict()
-        rule_dependencies = dict()
-        order = 0
         for rule in self.rules:
-            rule_order[rule] = order
-            # Rules are ultimately sorted by the earliest rule they must
-            # *precede*, so every rule should "depend" on the next one
-            rule_dependencies[rule] = [order + 1]
-            order += 1
-
             for selector in rule.selectors:
                 for key in selector.lookup_key():
                     key_to_selectors[key].add(selector)
@@ -1267,6 +1261,7 @@ class Compilation(object):
                     if candidate.is_superset_of(selector)]
 
                 if not extendable_selectors:
+                    # TODO should be fatal, unless !optional given
                     log.warn(
                         "Can't find any matching rules to extend: %s"
                         % selector.render())
@@ -1302,11 +1297,9 @@ class Compilation(object):
                         parent_rule.ancestry = (
                             parent_rule.ancestry.with_more_selectors(
                                 more_parent_selectors))
-                        rule_dependencies[parent_rule].append(rule_order[rule])
 
-        # clean up placeholder only rules
+        # Remove placeholder-only rules
         self.rules = [rule for rule in self.rules if not rule.is_pure_placeholder]
-        self.rules.sort(key=lambda rule: min(rule_dependencies[rule]))
 
     # @print_timing(3)
     def parse_properties(self):
diff --git a/scss/tests/files/bugs/extend-selector-order.css b/scss/tests/files/bugs/extend-selector-order.css
new file mode 100644
index 0000000..619fc57
--- /dev/null
+++ b/scss/tests/files/bugs/extend-selector-order.css
@@ -0,0 +1,7 @@
+.nav-pills > li {
+  float: left;
+}
+
+.nav-justified > li, .nav-tabs.nav-justified > li {
+  float: none;
+}
diff --git a/scss/tests/files/bugs/extend-selector-order.scss b/scss/tests/files/bugs/extend-selector-order.scss
new file mode 100644
index 0000000..9a54cb3
--- /dev/null
+++ b/scss/tests/files/bugs/extend-selector-order.scss
@@ -0,0 +1,17 @@
+.nav-tabs {
+  &.nav-justified {
+    @extend .nav-justified;
+  }
+}
+
+.nav-pills {
+  > li {
+    float: left;
+  }
+}
+
+.nav-justified {
+  > li {
+    float: none;
+  }
+}
diff --git a/scss/tests/files/original-doctests/007-extends-3.css b/scss/tests/files/original-doctests/007-extends-3.css
index 1b17778..1bb67f4 100644
--- a/scss/tests/files/original-doctests/007-extends-3.css
+++ b/scss/tests/files/original-doctests/007-extends-3.css
@@ -1,3 +1,7 @@
+.specialClass {
+  padding: 10px;
+  font-size: 14px;
+}
 .basicClass, .specialClass {
   padding: 20px;
   background-color: #FF0000;
@@ -5,7 +9,3 @@
 .basicClass a, .specialClass a, .specialLink {
   text-decoration: none;
 }
-.specialClass {
-  padding: 10px;
-  font-size: 14px;
-}
diff --git a/scss/tests/test_misc.py b/scss/tests/test_misc.py
index beb231a..0c6c140 100644
--- a/scss/tests/test_misc.py
+++ b/scss/tests/test_misc.py
@@ -84,14 +84,14 @@ def test_extend_across_files():
     '''
     actual = compiler.compile()
     expected = """\
-.basicClass, .specialClass {
-  padding: 20px;
-  background-color: #FF0000;
-}
 .specialClass {
   padding: 10px;
   font-size: 14px;
 }
+.basicClass, .specialClass {
+  padding: 20px;
+  background-color: #FF0000;
+}
 """
 
     assert expected == actual