From 1909bb43d9aecf7cf8bc7ddfc188bdf6defac457 Mon Sep 17 00:00:00 2001
From: David Mosher <davidmosher@gmail.com>
Date: Mon, 15 Jul 2019 19:18:18 -0400
Subject: [PATCH] bugfix: exempt the :root selector from prefix

- the change in #1705 introduced a small bug for users who were relying on assigning global CSS variables via the :root selector
- this change adds a small exemption to avoid prefixing :root with the random prefix that svelte adds
---
 src/compiler/compile/css/Selector.ts   | 4 +++-
 test/css/samples/css-vars/expected.css | 2 +-
 test/css/samples/css-vars/input.svelte | 5 ++++-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/compiler/compile/css/Selector.ts b/src/compiler/compile/css/Selector.ts
index 005e5320fd..ef54f789fc 100644
--- a/src/compiler/compile/css/Selector.ts
+++ b/src/compiler/compile/css/Selector.ts
@@ -62,7 +62,9 @@ export default class Selector {
 			while (i--) {
 				const selector = block.selectors[i];
 				if (selector.type === 'PseudoElementSelector' || selector.type === 'PseudoClassSelector') {
-					if (i === 0) code.prependRight(selector.start, attr);
+					if (selector.name !== 'root') {
+						if (i === 0) code.prependRight(selector.start, attr);
+					}
 					continue;
 				}
 
diff --git a/test/css/samples/css-vars/expected.css b/test/css/samples/css-vars/expected.css
index ccb7a3ec48..c2bd56375b 100644
--- a/test/css/samples/css-vars/expected.css
+++ b/test/css/samples/css-vars/expected.css
@@ -1 +1 @@
-div.svelte-xyz{--test:10}
\ No newline at end of file
+:root{--root-test:20}div.svelte-xyz{--test:10}
\ No newline at end of file
diff --git a/test/css/samples/css-vars/input.svelte b/test/css/samples/css-vars/input.svelte
index dafa7d09e4..7aa48617a4 100644
--- a/test/css/samples/css-vars/input.svelte
+++ b/test/css/samples/css-vars/input.svelte
@@ -1,7 +1,10 @@
 <div></div>
 
 <style>
+	:root {
+		--root-test: 20;
+	}
 	div {
 		--test: 10;
 	}
-</style>
\ No newline at end of file
+</style>