From 3af8b491b425985fbd3ee3f90fb1c7c43e87c824 Mon Sep 17 00:00:00 2001
From: Sam Atkins <atkinssj@serenityos.org>
Date: Tue, 22 Aug 2023 15:24:12 +0100
Subject: [PATCH] LibWeb: Implement `:any-link` and `:local-link` pseudo-class
 selectors

`:any-link` matches links, whether they have been visited or not.

`:local-link` matches links to the current URL.
---
 Tests/LibWeb/Ref/css-any-link-selector-ref.html |  1 +
 Tests/LibWeb/Ref/css-any-link-selector.html     |  6 ++++++
 .../LibWeb/Ref/css-local-link-selector-ref.html |  2 ++
 Tests/LibWeb/Ref/css-local-link-selector.html   |  7 +++++++
 Tests/LibWeb/Ref/manifest.json                  |  2 ++
 .../Libraries/LibWeb/CSS/PseudoClasses.json     |  6 ++++++
 .../Libraries/LibWeb/CSS/SelectorEngine.cpp     | 17 +++++++++++++++++
 7 files changed, 41 insertions(+)
 create mode 100644 Tests/LibWeb/Ref/css-any-link-selector-ref.html
 create mode 100644 Tests/LibWeb/Ref/css-any-link-selector.html
 create mode 100644 Tests/LibWeb/Ref/css-local-link-selector-ref.html
 create mode 100644 Tests/LibWeb/Ref/css-local-link-selector.html

diff --git a/Tests/LibWeb/Ref/css-any-link-selector-ref.html b/Tests/LibWeb/Ref/css-any-link-selector-ref.html
new file mode 100644
index 00000000000..c52dc9d82a3
--- /dev/null
+++ b/Tests/LibWeb/Ref/css-any-link-selector-ref.html
@@ -0,0 +1 @@
+<a href="example.com" style="color: orange">Link</a>
diff --git a/Tests/LibWeb/Ref/css-any-link-selector.html b/Tests/LibWeb/Ref/css-any-link-selector.html
new file mode 100644
index 00000000000..bc20a79168b
--- /dev/null
+++ b/Tests/LibWeb/Ref/css-any-link-selector.html
@@ -0,0 +1,6 @@
+<style>
+    :any-link {
+        color: orange;
+    }
+</style>
+<a href="example.com">Link</a>
diff --git a/Tests/LibWeb/Ref/css-local-link-selector-ref.html b/Tests/LibWeb/Ref/css-local-link-selector-ref.html
new file mode 100644
index 00000000000..44d033ca803
--- /dev/null
+++ b/Tests/LibWeb/Ref/css-local-link-selector-ref.html
@@ -0,0 +1,2 @@
+<a href="" style="color: orange">Local</a>
+<a href="example.com">Not local</a>
diff --git a/Tests/LibWeb/Ref/css-local-link-selector.html b/Tests/LibWeb/Ref/css-local-link-selector.html
new file mode 100644
index 00000000000..e9fbbdfd6f0
--- /dev/null
+++ b/Tests/LibWeb/Ref/css-local-link-selector.html
@@ -0,0 +1,7 @@
+<style>
+    :local-link {
+        color: orange;
+    }
+</style>
+<a href="">Local</a>
+<a href="example.com">Not local</a>
diff --git a/Tests/LibWeb/Ref/manifest.json b/Tests/LibWeb/Ref/manifest.json
index 09c36b5436f..60d30ac5b29 100644
--- a/Tests/LibWeb/Ref/manifest.json
+++ b/Tests/LibWeb/Ref/manifest.json
@@ -5,8 +5,10 @@
     "square-flex.html": "square-ref.html",
     "separate-borders-inline-table.html": "separate-borders-ref.html",
     "opacity-stacking.html": "opacity-stacking-ref.html",
+    "css-any-link-selector.html": "css-any-link-selector-ref.html",
     "css-gradient-currentcolor.html": "css-gradient-currentcolor-ref.html",
     "css-lang-selector.html": "css-lang-selector-ref.html",
+    "css-local-link-selector.html": "css-local-link-selector-ref.html",
     "css-gradients.html": "css-gradients-ref.html",
     "svg-symbol.html": "svg-symbol-ref.html",
     "svg-gradient-spreadMethod.html": "svg-gradient-spreadMethod-ref.html",
diff --git a/Userland/Libraries/LibWeb/CSS/PseudoClasses.json b/Userland/Libraries/LibWeb/CSS/PseudoClasses.json
index 5d2826acc6c..25f68d921d6 100644
--- a/Userland/Libraries/LibWeb/CSS/PseudoClasses.json
+++ b/Userland/Libraries/LibWeb/CSS/PseudoClasses.json
@@ -2,6 +2,9 @@
   "active": {
     "argument": ""
   },
+  "any-link": {
+    "argument": ""
+  },
   "buffering": {
     "argument": ""
   },
@@ -62,6 +65,9 @@
   "link": {
     "argument": ""
   },
+  "local-link": {
+    "argument": ""
+  },
   "muted": {
     "argument": ""
   },
diff --git a/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp b/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp
index 2d16da1ccf2..e7a25e9d7a7 100644
--- a/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp
+++ b/Userland/Libraries/LibWeb/CSS/SelectorEngine.cpp
@@ -213,7 +213,24 @@ static inline bool matches_pseudo_class(CSS::Selector::SimpleSelector::PseudoCla
 {
     switch (pseudo_class.type) {
     case CSS::PseudoClass::Link:
+    case CSS::PseudoClass::AnyLink:
+        // NOTE: AnyLink should match whether the link is visited or not, so if we ever start matching
+        //       :visited, we'll need to handle these differently.
         return matches_link_pseudo_class(element);
+    case CSS::PseudoClass::LocalLink: {
+        // The :local-link pseudo-class allows authors to style hyperlinks based on the users current location
+        // within a site. It represents an element that is the source anchor of a hyperlink whose target’s
+        // absolute URL matches the element’s own document URL. If the hyperlink’s target includes a fragment
+        // URL, then the fragment URL of the current URL must also match; if it does not, then the fragment
+        // URL portion of the current URL is not taken into account in the comparison.
+        if (!matches_link_pseudo_class(element))
+            return false;
+        auto document_url = element.document().url();
+        AK::URL target_url = element.document().parse_url(element.attribute(HTML::AttributeNames::href));
+        if (target_url.fragment().has_value())
+            return document_url.equals(target_url, AK::URL::ExcludeFragment::No);
+        return document_url.equals(target_url, AK::URL::ExcludeFragment::Yes);
+    }
     case CSS::PseudoClass::Visited:
         // FIXME: Maybe match this selector sometimes?
         return false;