@extend fixes

[robocoder]

Applied @nessy's patch from issue #29 but there are new errors reported by phpunit.

For example:

.hoverlink { @extend a:hover }
a:hover { text-decoration: underline }
#demo .overview .fakelink {@extend a}

scssphp (before) -- wrong in retrospect:

a:hover, .hoverlink {
   text-decoration: underline; }

scssphp (after):

a:hover, .hoverlink:hover, #demo .overview .fakelink:hover {
   text-decoration: underline; }

sass-lang.com:

a:hover, .hoverlink, #demo .overview .fakelink:hover {
  text-decoration: underline; }

[robocoder]

I'm going to try and fix the above bug.

Also I spotted some redundant selectors in the output, e.g.,

.foo .foo > .bar .bread, .foo > .bar .foo .bread {
    ... }

that ruby sass folds into:

.foo > .bar .bread {
    ... }

but I'll save that for another ticket/PR.

[nessy]

Hey robocoder,
Thanks for testing my solution,
I am quite new on github so dont realy know how everything works jet.

I think i dit found a solution for the first problem you found where the :hover does not get extended right.
just see if this helps you.
I might look for a solution for the nesting later.

protected function matchExtendsSingle($single, &$out_origin, &$out_rem) {
    $counts = array();
    foreach ($single as $part) {
        if (!is_string($part)) return false; // hmm

        if (isset($this->extendsMap[$part])) {
            foreach ($this->extendsMap[$part] as $idx) {

                $counts[$idx] =
                    isset($counts[$idx]) ? $counts[$idx] + 1 : 1;
            }
        }
    }

    $out_origin = array();
    // NEW
    $out_rem    = array();
    $found      = false;

    foreach ($counts as $idx => $count) {
        $target='';
        list($target, $origin) = $this->extends[$idx];

        // check count
        if ($count != count($target)) continue;
        // check if target is subset of single
        if (array_diff(array_intersect($single, $target), $target)) continue;

        $out_origin = array_merge($out_origin,$origin);
        // CHANGE
        $out_rem = array_merge($out_rem,array_diff($single, $target));

        $found = true;
    }
    return $found;
}

protected function combineSelectorSingle($base, $other) {
    $tag = null;
    $out = array();

    foreach (array($base, $other) as $single) {
        foreach ($single as $part) {
            if (preg_match('/^[^.#:]/', $part)) {
                $tag = $part;
            } else {
                $out[] = $part;
            }
        }
    }

    if ($tag) {
        array_unshift($out, $tag);
    }

    return $out;
}

protected function matchExtends($selector, &$out, $from = 0, $initial=true) {

    foreach ($selector as $i => $part) {
        if ($i < $from) continue;

        if ($this->matchExtendsSingle($part, $origin, $rem)) {

            $before = array_slice($selector, 0, $i);
            $after = array_slice($selector, $i + 1);

            // CHANGE
            foreach ($origin as $j => $new) {

                $new[count($new) - 1] =
                // CHANGE
                    $this->combineSelectorSingle(end($new), array($rem[$j]));

[robocoder]

@nessy thanks for digging into this again. The last line of your new change causes phpunit to fail with "Undefined offset: 0" when compiling tests/inputs/extends.scss and tests/inputs/placeholder_selector.scss

[robocoder]

Ok, I've fixed the first test case (mis-combined :hover). I'm still looking into the missing selectors from the nested test case.

[robocoder]

@leafo Ready for review.

[leafo]

Much better, thanks!

Found another difference, but I think it might be a bug in ruby one. Compare are how this is compiled:

.btn:hover {
  color: red;
}

.edit .actions button {
    @extend .btn;
}

.edit .new .actions button {
    @extend .btn;
}

scssphp:

.btn:hover, .edit .actions button:hover, .edit .new .actions button:hover {
  color: red; }

ruby scss:

.btn:hover, .edit .actions button:hover {
  color: red; }

[robocoder]

ruby scss has some optimizations to reduce selector bloat.

[MattiJarvinen-BA]

@leafo & @robocoder I believe this is the logic in Ruby SCSS optimization explained sass/sass#324 (comment)