Merge pull request #610 from stof/support_empty_var

Add support for empty fallback in var()

src/Parser.php

@@ -2804,6 +2804,10 @@ protected function func($name, &$func)
                     $this->argValues($args) &&
                     $this->matchChar(')')
                 ) {
+                    if ($name === 'var' && \count($args) === 2 && $args[1][0] === Type::T_NULL) {
+                        $args[1] = [null, [Type::T_STRING, '', [' ']], false];
+                    }
+
                     $func = [Type::T_FUNCTION_CALL, $name, $args];
 
                     return true;

tests/inputs/empty_fallback_var.scss

@@ -0,0 +1,2 @@
+// adaptation of css/plain/functions/empty_fallback_var from sass-spec as we don't match the output exactly (but CSS is equivalent)
+@import "empty_fallback_var_imports/plain";

tests/inputs/empty_fallback_var_imports/plain.css

@@ -0,0 +1 @@
+a {b: var(--c, )}

tests/outputs/empty_fallback_var.css

@@ -0,0 +1,3 @@
+a {
+  b: var(--c,  );
+}