From 7b4a0a0eae74a73f9834f1e46e72e6bb7a7fc631 Mon Sep 17 00:00:00 2001
From: ExE Boss <3889017+ExE-Boss@users.noreply.github.com>
Date: Wed, 4 Sep 2019 15:30:00 +0200
Subject: [PATCH] =?UTF-8?q?feat:=20Remove=C2=A0universal=C2=A0selector=20w?=
 =?UTF-8?q?hen=C2=A0mixed=20with=20a=C2=A0tag=C2=A0name=C2=A0selector?=
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---
 src/replaceRuleSelector.js | 44 ++++++++++++++++++++++++++++++++++++--
 test/index.js              | 25 ++++++++++++++++++++++
 2 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/src/replaceRuleSelector.js b/src/replaceRuleSelector.js
index 118b51e..4b1f32d 100644
--- a/src/replaceRuleSelector.js
+++ b/src/replaceRuleSelector.js
@@ -4,6 +4,8 @@ import balancedMatch from "balanced-match"
 
 const pseudoClass = ":matches"
 const selectorElementRE = /^[a-zA-Z]/
+const selectorUniversalRE = /^\*(?!\|)/
+const selectorNamespacedUniversalRE = /\|\*$/
 
 function isElementSelector(selector) {
   const matches = selectorElementRE.exec(selector)
@@ -11,9 +13,47 @@ function isElementSelector(selector) {
   return matches
 }
 
+function isUniversalSelector(selector) {
+  const matches = selectorUniversalRE.exec(selector)
+  // console.log({selector, matches})
+  return matches
+}
+
+function isUniversalSelectorWithNS(selector) {
+  const matches = selectorNamespacedUniversalRE.exec(selector)
+  // console.log({selector, matches})
+  return matches
+}
+
 function normalizeSelector(selector, preWhitespace, pre) {
-  if (isElementSelector(selector) && !isElementSelector(pre)) {
-    return `${ preWhitespace}${ selector }${ pre }`
+  if (isUniversalSelector(selector) && isUniversalSelector(pre)) {
+    return `${ preWhitespace }${ pre }${ selector.substring(1) }`
+  }
+
+  if (isElementSelector(pre)) {
+    if (isUniversalSelector(selector)) {
+      return `${ preWhitespace }${ pre }${ selector.substring(1) }`
+    }
+    else if (isUniversalSelectorWithNS(selector)) {
+      return `${ preWhitespace }${
+        selector.substring(0, selector.length - 1)
+      }${ pre }`
+    }
+  }
+
+  if (isElementSelector(selector)) {
+    if (isUniversalSelector(pre)) {
+      return `${ preWhitespace }${ selector }${ pre.substring(1) }`
+    }
+    else if (isUniversalSelectorWithNS(pre)) {
+      return `${ preWhitespace }${
+        pre.substring(0, pre.length - 1)
+      }${ selector }`
+    }
+
+    else if (!isElementSelector(pre)) {
+      return `${ preWhitespace}${ selector }${ pre }`
+    }
   }
 
   return `${ preWhitespace }${ pre }${ selector }`
diff --git a/test/index.js b/test/index.js
index 77d9def..0424da3 100644
--- a/test/index.js
+++ b/test/index.js
@@ -160,5 +160,30 @@ article h3 + p {}`,
     "regression https://github.com/postcss/postcss-selector-matches/issues/10"
   )
 
+  t.equal(
+    transform(
+      "*:matches(a), " +
+        "c:matches(*), " +
+        "ns|*:matches(b), " +
+        "*|*:matches(d), " +
+        "*:matches(ns|e) {}"
+    ),
+    "a, c, ns|b, *|d, ns|e {}",
+    "universal selector is removed when mixed with a tag name selector"
+  )
+
+  t.equal(
+    transform("*.foo:matches(bar) {}"),
+    "bar.foo {}",
+    "universal selector is removed from compound selector when mixed with " +
+      "a tag name selector"
+  )
+
+  t.equal(
+    transform("*.foo:matches(*.bar, tag:baz), *:matches(*) {}"),
+    "*.foo.bar, tag:baz.foo, * {}",
+    "only one universal selector is kept"
+  )
+
   t.end()
 })