[FEATURE] Support :only-of-type (#856)

Closes #849

CHANGELOG.md

@@ -6,6 +6,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 ## x.y.z
 
 ### Added
+- Support `:only-of-type` (with a type)
+  ([#849](https://github.com/MyIntervals/emogrifier/issues/849),
+  [#856](https://github.com/MyIntervals/emogrifier/pull/856))
 - Configuration setting methods now all return `$this` to allow chaining
   ([#824](https://github.com/MyIntervals/emogrifier/pull/824),
   [#854](https://github.com/MyIntervals/emogrifier/pull/854))

README.md

@@ -320,6 +320,8 @@ Emogrifier currently supports the following
    * [nth-of-type()](https://developer.mozilla.org/en-US/docs/Web/CSS/:nth-of-type)
      (with a type)
    * [only-child](https://developer.mozilla.org/en-US/docs/Web/CSS/:only-child)
+   * [only-of-type](https://developer.mozilla.org/en-US/docs/Web/CSS/:only-of-type)
+     (with a type)
 
 The following selectors are not implemented yet:
 
@@ -337,7 +339,6 @@ The following selectors are not implemented yet:
      will nonetheless be preserved and copied to a `<style>` element in the 
      HTML – including (but not necessarily limited to) the following:
      * [any-link](https://developer.mozilla.org/en-US/docs/Web/CSS/:any-link)
-     * [only-of-type](https://developer.mozilla.org/en-US/docs/Web/CSS/:only-of-type)
      * [optional](https://developer.mozilla.org/en-US/docs/Web/CSS/:optional)
      * [required](https://developer.mozilla.org/en-US/docs/Web/CSS/:required)
 

composer.json

@@ -40,7 +40,7 @@
         "php": "~7.0 || ~7.1 || ~7.2 || ~7.3 || ~7.4",
         "ext-dom": "*",
         "ext-libxml": "*",
-        "symfony/css-selector": "^3.4 || ^4.3 || ^5.0"
+        "symfony/css-selector": "^3.4.32 || ^4.3.5 || ^5.0"
     },
     "require-dev": {
         "grogy/php-parallel-lint": "^1.1.0",

src/CssInliner.php

@@ -53,8 +53,7 @@ class CssInliner extends AbstractHtmlProcessor
      *
      * @var string
      */
-    const PSEUDO_CLASS_MATCHER
-        = 'empty|(?:first|last|nth(?:-last)?+|only)-child|(?:first|last|nth(?:-last)?+)-of-type|not\\([[:ascii:]]*\\)';
+    const PSEUDO_CLASS_MATCHER = 'empty|(?:first|last|nth(?:-last)?+|only)-(?:child|of-type)|not\\([[:ascii:]]*\\)';
 
     /**
      * @var bool[]

tests/Unit/CssInlinerTest.php

@@ -603,7 +603,12 @@ public function matchedCssDataProvider(): array
                 'div:last-of-type { %1$s }',
                 '<div class="div-3" style="%1$s">',
             ],
-            // broken: only-of-type (https://github.com/symfony/symfony/issues/33773)
+            // broken: only-of-type without preceding type
+            'type & :only-of-type => only child' => ['span:only-of-type { %1$s }', '<span style="%1$s">'],
+            'type & :only-of-type => only of that type' => [
+                'div:only-of-type { %1$s }',
+                '<div class="div-3" style="%1$s">',
+            ],
             // broken: nth-of-type without preceding type
             'type & :nth-of-type(even) => 2nd of many of type' => [
                 'p:nth-of-type(even) { %1$s }',
@@ -903,6 +908,7 @@ public function nonMatchedCssDataProvider(): array
             'type & :first-of-type => not last of many' => ['p:first-of-type { %1$s }', '<p class="p-7">'],
             'type & :last-of-type => not 1st of many' => ['p:last-of-type { %1$s }', '<p class="p-1">'],
             'type & :last-of-type => not 2nd last of many' => ['p:last-of-type { %1$s }', '<p class="p-6">'],
+            'type & :only-of-type => not one of many' => ['p:only-of-type { %1$s }', '<p class="p-1">'],
             'type & :nth-of-type(even) => not 1st of many of type' => [
                 'p:nth-of-type(even) { %1$s }',
                 '<p class="p-1">',
@@ -2151,7 +2157,6 @@ public function matchingSelectorWithPseudoComponentCssRuleDataProvider(): array
         ];
         $datasetsWithUnsupportedStaticPseudoClasses = [
             ':any-link' => ['a:any-link { color: green; }'],
-            ':only-of-type' => ['a:only-of-type { color: green; }'],
             ':optional' => ['input:optional { color: green; }'],
             ':required' => ['input:required { color: green; }'],
         ];