From 89edb0e754b72bfc8db573e7ffea952d4e0c21e3 Mon Sep 17 00:00:00 2001
From: obedparla <obed.marquezp@gmail.com>
Date: Thu, 5 Nov 2020 00:26:54 +0100
Subject: [PATCH 1/8] Add stripEmptyProperties and improve stripEmptyTags

---
 src/CSS.php | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/CSS.php b/src/CSS.php
index 89fcf1bb..f46db863 100644
--- a/src/CSS.php
+++ b/src/CSS.php
@@ -310,6 +310,7 @@ public function execute($path = null, $parents = array())
             $this->extractCalcs();
             $css = $this->replace($css);
 
+            $css = $this->stripEmptyProperties($css);
             $css = $this->stripWhitespace($css);
             $css = $this->shortenColors($css);
             $css = $this->shortenZeroes($css);
@@ -617,11 +618,27 @@ protected function shortenZeroes($content)
     protected function stripEmptyTags($content)
     {
         $content = preg_replace('/(?<=^)[^\{\};]+\{\s*\}/', '', $content);
-        $content = preg_replace('/(?<=(\}|;))[^\{\};]+\{\s*\}/', '', $content);
+        // Remove empty tags/selectors
+        $content = preg_replace('/(?<=(\}|;|\{))[^\{\};]+\{\s*\}/', '', $content);
+        // Run it again to remove empty media queries that had the empty selectors before
+        $content = preg_replace('/(?<=(\}|;|\{))[^\{\};]+\{\s*\}/', '', $content);
 
         return $content;
     }
 
+    /**
+     * Strip empty properties from source code.
+     * i.e: 'color: ;'
+     *
+     * @param string $content
+     *
+     * @return string
+     */
+    protected function stripEmptyProperties($content)
+    {
+        return preg_replace('/[a-z-:()]*:\s*;/', '', $content);
+    }
+
     /**
      * Strip comments from source code.
      */

From db1d0a6b9958173e945639a9aefe477a2cf89e9d Mon Sep 17 00:00:00 2001
From: obedparla <obed.marquezp@gmail.com>
Date: Thu, 5 Nov 2020 00:28:33 +0100
Subject: [PATCH 2/8] Add test for stripping empty properties and better empty
 tags

---
 tests/css/CSSTest.php | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/tests/css/CSSTest.php b/tests/css/CSSTest.php
index 76f80aba..8b9ea23a 100644
--- a/tests/css/CSSTest.php
+++ b/tests/css/CSSTest.php
@@ -502,7 +502,7 @@ public function dataProvider()
     calc(100% - 15px) calc(1em + 2px),
     calc(100% - 2.5em) 0.5em;
 }',
-	      	'.cvp-live-filter select{background-position:calc(100% - 20px) calc(1em + 2px),calc(100% - 15px) calc(1em + 2px),calc(100% - 2.5em) .5em}',    
+	      	'.cvp-live-filter select{background-position:calc(100% - 20px) calc(1em + 2px),calc(100% - 15px) calc(1em + 2px),calc(100% - 2.5em) .5em}',
         );
 
         // https://github.com/matthiasmullie/minify/issues/301
@@ -800,6 +800,42 @@ public function dataProvider()
             'ul p{padding-left:calc((var(--icon-size) / 2) + var(--horisontal-space))}',
         );
 
+        $tests[] = array('
+body{
+     background: white;
+}
+
+.classWithEmptyProperties {
+    color: ;
+    font-size: ;
+}
+
+@media(max-width: 576px) {
+    .emptyClass {
+    }
+
+    .nonEmptyClass {
+        display: flex;
+    }
+}
+
+@media(max-width: 850px) {
+    .emptyClassWithEmptyProperties {
+        color: ;
+        font-size: ;
+    }
+
+    #emptyId {
+    }
+}
+
+@media(max-width: 1580px) {
+    #emptyId {
+    }
+}
+', 'body{background:#fff}@media(max-width:576px){.nonEmptyClass{display:flex}}',
+        );
+
         return $tests;
     }
 

From 921df08623ab517521522021dd05887ca391c3f8 Mon Sep 17 00:00:00 2001
From: obedparla <obed.marquezp@gmail.com>
Date: Thu, 5 Nov 2020 00:45:16 +0100
Subject: [PATCH 3/8] Improve the strip properties function and test

---
 src/CSS.php           | 2 +-
 tests/css/CSSTest.php | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/CSS.php b/src/CSS.php
index f46db863..94e559ca 100644
--- a/src/CSS.php
+++ b/src/CSS.php
@@ -636,7 +636,7 @@ protected function stripEmptyTags($content)
      */
     protected function stripEmptyProperties($content)
     {
-        return preg_replace('/[a-z-:()]*:\s*;/', '', $content);
+        return preg_replace('/[a-z-:().#]*:\s*;/', '', $content);
     }
 
     /**
diff --git a/tests/css/CSSTest.php b/tests/css/CSSTest.php
index 8b9ea23a..88706b00 100644
--- a/tests/css/CSSTest.php
+++ b/tests/css/CSSTest.php
@@ -806,8 +806,9 @@ public function dataProvider()
 }
 
 .classWithEmptyProperties {
-    color: ;
+    color::hover: ;
     font-size: ;
+    font-weight::hover:not(#id.class): ;
 }
 
 @media(max-width: 576px) {
@@ -822,7 +823,6 @@ public function dataProvider()
 @media(max-width: 850px) {
     .emptyClassWithEmptyProperties {
         color: ;
-        font-size: ;
     }
 
     #emptyId {

From 43f64ba4c1c70b767710a512a9c2fa17b0a77a8c Mon Sep 17 00:00:00 2001
From: obedparla <obed.marquezp@gmail.com>
Date: Thu, 5 Nov 2020 01:00:31 +0100
Subject: [PATCH 4/8] Add comments to stripEmptyTags

---
 src/CSS.php | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/CSS.php b/src/CSS.php
index 94e559ca..93a3c85f 100644
--- a/src/CSS.php
+++ b/src/CSS.php
@@ -617,10 +617,11 @@ protected function shortenZeroes($content)
      */
     protected function stripEmptyTags($content)
     {
+        // Remove empty tags/selectors at the start of the file
         $content = preg_replace('/(?<=^)[^\{\};]+\{\s*\}/', '', $content);
-        // Remove empty tags/selectors
+        // Remove empty tags/selectors (classes, ids and so on)
         $content = preg_replace('/(?<=(\}|;|\{))[^\{\};]+\{\s*\}/', '', $content);
-        // Run it again to remove empty media queries that had the empty selectors before
+        // Run it again to remove any empty media queries that had the empty selectors before
         $content = preg_replace('/(?<=(\}|;|\{))[^\{\};]+\{\s*\}/', '', $content);
 
         return $content;

From 78215e3bd0171f7715f1e1dce2c8e90204fc2ed6 Mon Sep 17 00:00:00 2001
From: Obed Marquez Parlapiano <obed.marquezp@gmail.com>
Date: Mon, 4 Oct 2021 19:46:40 +0200
Subject: [PATCH 5/8] fix(css minify): add uppercase letters so that it works
 with css vars

---
 src/CSS.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/CSS.php b/src/CSS.php
index 93a3c85f..ef38fa01 100644
--- a/src/CSS.php
+++ b/src/CSS.php
@@ -637,7 +637,7 @@ protected function stripEmptyTags($content)
      */
     protected function stripEmptyProperties($content)
     {
-        return preg_replace('/[a-z-:().#]*:\s*;/', '', $content);
+        return preg_replace('/[a-zA-Z-:().#]*:\s*;/', '', $content);
     }
 
     /**

From bec356ee2376069c9af935f874dcf8e14f7e0cd0 Mon Sep 17 00:00:00 2001
From: Obed Marquez Parlapiano <obed.marquezp@gmail.com>
Date: Mon, 4 Oct 2021 20:33:51 +0200
Subject: [PATCH 6/8] Revert "fix(css minify): add uppercase letters so that it
 works with css vars"

This reverts commit 78215e3bd0171f7715f1e1dce2c8e90204fc2ed6.
---
 src/CSS.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/CSS.php b/src/CSS.php
index ef38fa01..93a3c85f 100644
--- a/src/CSS.php
+++ b/src/CSS.php
@@ -637,7 +637,7 @@ protected function stripEmptyTags($content)
      */
     protected function stripEmptyProperties($content)
     {
-        return preg_replace('/[a-zA-Z-:().#]*:\s*;/', '', $content);
+        return preg_replace('/[a-z-:().#]*:\s*;/', '', $content);
     }
 
     /**

From 9409fcbcdb3f6f409e4e0aa35fbc9d0a10eba384 Mon Sep 17 00:00:00 2001
From: Obed Marquez Parlapiano <obed.marquezp@gmail.com>
Date: Mon, 4 Oct 2021 20:38:08 +0200
Subject: [PATCH 7/8] fix: add uppercase letters so that it works with css vars

- A var such as --myColor would break.
---
 src/CSS.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/CSS.php b/src/CSS.php
index 93a3c85f..ef38fa01 100644
--- a/src/CSS.php
+++ b/src/CSS.php
@@ -637,7 +637,7 @@ protected function stripEmptyTags($content)
      */
     protected function stripEmptyProperties($content)
     {
-        return preg_replace('/[a-z-:().#]*:\s*;/', '', $content);
+        return preg_replace('/[a-zA-Z-:().#]*:\s*;/', '', $content);
     }
 
     /**

From 21c7dc49d465d24785477470be7070151ca054b8 Mon Sep 17 00:00:00 2001
From: Obed Marquez Parlapiano <obed.marquezp@gmail.com>
Date: Mon, 4 Oct 2021 20:42:55 +0200
Subject: [PATCH 8/8] Tests: add tests for css var with lower and uppercase
 letters

---
 tests/css/CSSTest.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/css/CSSTest.php b/tests/css/CSSTest.php
index 88706b00..b0a9c356 100644
--- a/tests/css/CSSTest.php
+++ b/tests/css/CSSTest.php
@@ -817,12 +817,15 @@ public function dataProvider()
 
     .nonEmptyClass {
         display: flex;
+        --myColorVar: #fff;
+        color: var(--myColorVar);
     }
 }
 
 @media(max-width: 850px) {
     .emptyClassWithEmptyProperties {
         color: ;
+        --myEmptyColor: ;
     }
 
     #emptyId {
@@ -833,7 +836,7 @@ public function dataProvider()
     #emptyId {
     }
 }
-', 'body{background:#fff}@media(max-width:576px){.nonEmptyClass{display:flex}}',
+', 'body{background:#fff}@media(max-width:576px){.nonEmptyClass{display:flex;--myColorVar: #fff;color: var(--myColorVar)}}',
         );
 
         return $tests;