From f60b3140fce44d6023ea28f20f1fdbe7b78d6e89 Mon Sep 17 00:00:00 2001
From: Lea Verou <lea@verou.me>
Date: Mon, 14 Sep 2020 04:07:02 +0300
Subject: [PATCH] Create 19-supports.js

---
 js/19-supports.js | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 js/19-supports.js

diff --git a/js/19-supports.js b/js/19-supports.js
new file mode 100644
index 0000000..a669803
--- /dev/null
+++ b/js/19-supports.js
@@ -0,0 +1,30 @@
+export default function compute() {
+
+let ret = {};
+
+walkRules(ast, rule => {
+	incrementByKey(ret, "total");
+
+	let condition = rule.supports;
+
+	// Drop whitespace around parens
+	condition = condition.replace(/\s*\(\s*/g, "(").replace(/\s*\)\s*/g, ")");
+
+	// Match property: value queries first
+	for (let match of condition.matchAll(/\([\w-]+\s*:/g)) {
+		let arg = parsel.gobbleParens(condition, match.index);
+		incrementByKey(ret, arg);
+	}
+
+	// Then find selector queries
+	for (let match of condition.matchAll(/selector\(/gi)) {
+		let arg = parsel.gobbleParens(condition, match.index + match[0].length - 1);
+		incrementByKey(ret, "selector" + arg);
+	}
+}, {type: "supports"});
+
+ret = sortObject(ret);
+
+return ret;
+
+}