LibWeb: Implement Range.set{Start,End}{Before,After}

Userland/Libraries/LibWeb/DOM/Range.cpp

@@ -171,6 +171,62 @@ ExceptionOr<void> Range::set_end(Node& node, u32 offset)
     return set_start_or_end(node, offset, StartOrEnd::End);
 }
 
+// https://dom.spec.whatwg.org/#dom-range-setstartbefore
+ExceptionOr<void> Range::set_start_before(Node& node)
+{
+    // 1. Let parent be node’s parent.
+    auto* parent = node.parent();
+
+    // 2. If parent is null, then throw an "InvalidNodeTypeError" DOMException.
+    if (!parent)
+        return InvalidNodeTypeError::create("Given node has no parent.");
+
+    // 3. Set the start of this to boundary point (parent, node’s index).
+    return set_start_or_end(*parent, node.index(), StartOrEnd::Start);
+}
+
+// https://dom.spec.whatwg.org/#dom-range-setstartafter
+ExceptionOr<void> Range::set_start_after(Node& node)
+{
+    // 1. Let parent be node’s parent.
+    auto* parent = node.parent();
+
+    // 2. If parent is null, then throw an "InvalidNodeTypeError" DOMException.
+    if (!parent)
+        return InvalidNodeTypeError::create("Given node has no parent.");
+
+    // 3. Set the start of this to boundary point (parent, node’s index plus 1).
+    return set_start_or_end(*parent, node.index() + 1, StartOrEnd::Start);
+}
+
+// https://dom.spec.whatwg.org/#dom-range-setendbefore
+ExceptionOr<void> Range::set_end_before(Node& node)
+{
+    // 1. Let parent be node’s parent.
+    auto* parent = node.parent();
+
+    // 2. If parent is null, then throw an "InvalidNodeTypeError" DOMException.
+    if (!parent)
+        return InvalidNodeTypeError::create("Given node has no parent.");
+
+    // 3. Set the end of this to boundary point (parent, node’s index).
+    return set_start_or_end(*parent, node.index(), StartOrEnd::End);
+}
+
+// https://dom.spec.whatwg.org/#dom-range-setendafter
+ExceptionOr<void> Range::set_end_after(Node& node)
+{
+    // 1. Let parent be node’s parent.
+    auto* parent = node.parent();
+
+    // 2. If parent is null, then throw an "InvalidNodeTypeError" DOMException.
+    if (!parent)
+        return InvalidNodeTypeError::create("Given node has no parent.");
+
+    // 3. Set the end of this to boundary point (parent, node’s index plus 1).
+    return set_start_or_end(*parent, node.index() + 1, StartOrEnd::End);
+}
+
 NonnullRefPtr<Range> Range::clone_range() const
 {
     return adopt_ref(*new Range(const_cast<Node&>(*m_start_container), m_start_offset, const_cast<Node&>(*m_end_container), m_end_offset));

Userland/Libraries/LibWeb/DOM/Range.h

@@ -26,6 +26,10 @@ public:
 
     ExceptionOr<void> set_start(Node& node, u32 offset);
     ExceptionOr<void> set_end(Node& node, u32 offset);
+    ExceptionOr<void> set_start_before(Node& node);
+    ExceptionOr<void> set_start_after(Node& node);
+    ExceptionOr<void> set_end_before(Node& node);
+    ExceptionOr<void> set_end_after(Node& node);
 
     NonnullRefPtr<Range> inverted() const;
     NonnullRefPtr<Range> normalized() const;

Userland/Libraries/LibWeb/DOM/Range.idl

@@ -10,6 +10,10 @@ interface Range : AbstractRange {
 
     undefined setStart(Node node, unsigned long offset);
     undefined setEnd(Node node, unsigned long offset);
+    undefined setStartBefore(Node node);
+    undefined setStartAfter(Node node);
+    undefined setEndBefore(Node node);
+    undefined setEndAfter(Node node);
 
     Range cloneRange();