Preserve space before parens (#1806)

src/printer.js

@@ -2786,6 +2786,9 @@ function genericPrintNoParens(path, options, print, args) {
       return concat([n.value, path.call(print, "group")]);
     }
     case "value-paren": {
+      if (n.raws.before !== "") {
+        return concat([line, n.value]);
+      }
       return n.value;
     }
     case "value-number": {

tests/css_parens/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,25 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`parens.js 1`] = `
+a {
+  box-shadow: inset 0 $size $size (-$size) black;
+  width: calc(100% - (#{var(--g-spacing)} - #{$iframe-x-padding}) * 2);
+  padding-right: (100% * $info-width / (1 - $image-width));
+  padding-bottom:
+    (
+      100% *
+      $image-height / ($image-width-responsive + $image-margin-responsive * 2)
+    );
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+a {
+  box-shadow: inset 0 $size $size (-$size) black;
+  width: calc(100% - (#{var(--g-spacing)} - #{$iframe-x-padding}) * 2);
+  padding-right: (100% * $info-width / (1 - $image-width));
+  padding-bottom: (
+    100% *
+      $image-height / ($image-width-responsive + $image-margin-responsive * 2)
+  );
+}
+
+`;

tests/css_parens/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, { parser: "postcss" });

tests/css_parens/parens.js

@@ -0,0 +1,10 @@
+a {
+  box-shadow: inset 0 $size $size (-$size) black;
+  width: calc(100% - (#{var(--g-spacing)} - #{$iframe-x-padding}) * 2);
+  padding-right: (100% * $info-width / (1 - $image-width));
+  padding-bottom:
+    (
+      100% *
+      $image-height / ($image-width-responsive + $image-margin-responsive * 2)
+    );
+}