LibWeb: Add HTMLPreElement width property

Author: https://github.com/bplaat
Commit: https://github.com/SerenityOS/serenity/commit/089a98607c
Pull-request: https://github.com/SerenityOS/serenity/pull/23261
Reviewed-by: https://github.com/ADKaster ✅

Tests/LibWeb/Text/expected/HTML/pre-width.txt

@@ -0,0 +1,3 @@
+1. 20
+2. 0
+3. 0

Tests/LibWeb/Text/input/HTML/pre-width.html

@@ -0,0 +1,29 @@
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        let testCounter = 1;
+        function testPart(part) {
+            println(`${testCounter++}. ${JSON.stringify(part())}`);
+        }
+
+        // 1. Set the pre element width attributes
+        testPart(() => {
+            const pre = document.createElement('pre');
+            pre.width = 20;
+            return pre.width;
+        });
+
+        // 2. Set the pre element width attributes with invalid data
+        testPart(() => {
+            const pre = document.createElement('pre');
+            pre.width = 'dsafds';
+            return pre.width;
+        });
+
+        // 3. Get the pre element width attribute default value
+        testPart(() => {
+            const pre = document.createElement('pre');
+            return pre.width;
+        });
+    });
+</script>

Userland/Libraries/LibWeb/HTML/HTMLPreElement.cpp

@@ -8,6 +8,7 @@
 #include <LibWeb/CSS/StyleProperties.h>
 #include <LibWeb/CSS/StyleValues/IdentifierStyleValue.h>
 #include <LibWeb/HTML/HTMLPreElement.h>
+#include <LibWeb/HTML/Numbers.h>
 
 namespace Web::HTML {
 
@@ -36,4 +37,20 @@ void HTMLPreElement::apply_presentational_hints(CSS::StyleProperties& style) con
     });
 }
 
+// https://html.spec.whatwg.org/multipage/obsolete.html#dom-pre-width
+WebIDL::Long HTMLPreElement::width() const
+{
+    // The width IDL attribute of the pre element must reflect the content attribute of the same name.
+    if (auto width_string = get_attribute(HTML::AttributeNames::width); width_string.has_value()) {
+        if (auto width = parse_integer(*width_string); width.has_value())
+            return *width;
+    }
+    return 0;
+}
+
+WebIDL::ExceptionOr<void> HTMLPreElement::set_width(WebIDL::Long width)
+{
+    return set_attribute(HTML::AttributeNames::width, MUST(String::number(width)));
+}
+
 }

Userland/Libraries/LibWeb/HTML/HTMLPreElement.h

@@ -8,6 +8,7 @@
 
 #include <LibWeb/ARIA/Roles.h>
 #include <LibWeb/HTML/HTMLElement.h>
+#include <LibWeb/WebIDL/Types.h>
 
 namespace Web::HTML {
 
@@ -21,6 +22,9 @@ public:
     // https://www.w3.org/TR/html-aria/#el-pre
     virtual Optional<ARIA::Role> default_role() const override { return ARIA::Role::generic; }
 
+    WebIDL::Long width() const;
+    WebIDL::ExceptionOr<void> set_width(WebIDL::Long);
+
 private:
     HTMLPreElement(DOM::Document&, DOM::QualifiedName);
 

Userland/Libraries/LibWeb/HTML/HTMLPreElement.idl

@@ -7,6 +7,6 @@ interface HTMLPreElement : HTMLElement {
     [HTMLConstructor] constructor();
 
     // Obsolete
-    // FIXME: [CEReactions, Reflect] attribute long width;
+    [CEReactions] attribute long width;
 
 };