Interpolation in comments

src/Compiler.php

@@ -1349,7 +1349,11 @@ protected function compileBlock(Block $block)
     protected function compileComment($block)
     {
         $out = $this->makeOutputBlock(Type::T_COMMENT);
-        $out->lines[] = $block[1];
+        if (is_string($block[1])) {
+            $out->lines[] = $block[1];
+        } else {
+            $out->lines[] = $this->compileValue($block[1]);
+        }
 
         $this->scope->children[] = $out;
     }

src/Parser.php

@@ -662,9 +662,12 @@ protected function parseChunk()
         }
 
         // opening css block
-        if ($this->selectors($selectors) && $this->matchChar('{')) {
+        if ($this->selectors($selectors) && $this->matchChar('{', false)) {
             $this->pushBlock($selectors, $s);
-
+            if ($this->eatWhiteDefault) {
+                $this->whitespace();
+                $this->append(null); // collect comments at the begining if needed
+            }
             return true;
         }
 
@@ -980,12 +983,49 @@ protected function whitespace()
 
         while (preg_match(static::$whitePattern, $this->buffer, $m, null, $this->count)) {
             if (isset($m[1]) && empty($this->commentsSeen[$this->count])) {
-                $this->appendComment([Type::T_COMMENT, $m[1]]);
+                // comment that are kept in the output CSS
+                $comment = [];
+                $endCommentCount = $this->count + strlen($m[1]);
+                // find interpolations in comment
+                $p = strpos($this->buffer, '#{', $this->count);
+                while ($p !== false && $p < $endCommentCount) {
+                    $c = substr($this->buffer, $this->count, $p - $this->count);
+                    $comment[] = $c;
+                    $this->count = $p;
+
+                    $out = null;
+                    if ($this->interpolation($out)) {
+                        // keep right spaces in the following string part
+                        if ($out[3]) {
+                            while ($this->buffer[$this->count-1] !== '}') {
+                                $this->count--;
+                            }
+                            $out[3] = '';
+                        }
+                        $comment[] = $out;
+                    } else {
+                        $comment[] = substr($this->buffer, $this->count, 2);
+                        $this->count += 2;
+                    }
+
+                    $p = strpos($this->buffer, '#{', $this->count);
+                }
+                // remaining part
+                $c = substr($this->buffer, $this->count, $endCommentCount - $this->count);
 
+                if (!$comment) {
+                    // single part static comment
+                    $this->appendComment([Type::T_COMMENT, $c]);
+                } else {
+                    $comment[] = $c;
+                    $this->appendComment([Type::T_COMMENT, [Type::T_STRING, '', $comment]]);
+                }
                 $this->commentsSeen[$this->count] = true;
+                $this->count = $endCommentCount;
+            } else {
+                // comment that are ignored and not kept in the output css
+                $this->count += strlen($m[0]);
             }
-
-            $this->count += strlen($m[0]);
             $gotWhite = true;
         }
 
@@ -999,7 +1039,9 @@ protected function whitespace()
      */
     protected function appendComment($comment)
     {
-        $comment[1] = substr(preg_replace(['/^\s+/m', '/^(.)/m'], ['', ' \1'], $comment[1]), 1);
+        if ($comment[0] === Type::T_COMMENT && is_string($comment[1])) {
+            $comment[1] = substr(preg_replace(['/^\s+/m', '/^(.)/m'], ['', ' \1'], $comment[1]), 1);
+        }
 
         $this->env->comments[] = $comment;
     }
@@ -1012,15 +1054,17 @@ protected function appendComment($comment)
      */
     protected function append($statement, $pos = null)
     {
-        if ($pos !== null) {
-            list($line, $column) = $this->getSourcePosition($pos);
+        if (! is_null($statement)) {
+            if ($pos !== null) {
+                list($line, $column) = $this->getSourcePosition($pos);
 
-            $statement[static::SOURCE_LINE]   = $line;
-            $statement[static::SOURCE_COLUMN] = $column;
-            $statement[static::SOURCE_INDEX]  = $this->sourceIndex;
-        }
+                $statement[static::SOURCE_LINE]   = $line;
+                $statement[static::SOURCE_COLUMN] = $column;
+                $statement[static::SOURCE_INDEX]  = $this->sourceIndex;
+            }
 
-        $this->env->children[] = $statement;
+            $this->env->children[] = $statement;
+        }
 
         $comments = $this->env->comments;
 

tests/inputs/comments.scss

@@ -45,4 +45,23 @@ a {
 
 // коммент
 
+$color:red;
+$radius:2px;
+
+/* This is a comment with vars references:
+color:#{$color}
+and a fake #{ doing nothing
+radius:#{$radius}
+ */
+
 // end
+
+// comment position in blocks
+.textimage-background-fullheight {
+  .background {
+    /* @noflip */
+    display: block;
+    /* hop */
+    width: 100%;
+  }
+}

tests/outputs/comments.css

@@ -30,3 +30,13 @@ a {
   /* comment 6 */ }
 /* comment 7 */
 /* коммент */
+/* This is a comment with vars references:
+color:red
+and a fake #{ doing nothing
+radius:2px
+ */
+.textimage-background-fullheight .background {
+  /* @noflip */
+  display: block;
+  /* hop */
+  width: 100%; }

tests/outputs_numbered/comments.css

@@ -32,3 +32,15 @@ a {
   /* comment 6 */ }
 /* comment 7 */
 /* коммент */
+/* This is a comment with vars references:
+color:red
+and a fake #{ doing nothing
+radius:2px
+ */
+/* line 60, inputs/comments.scss */
+/* line 61, inputs/comments.scss */
+  .textimage-background-fullheight .background {
+    /* @noflip */
+    display: block;
+    /* hop */
+    width: 100%; }