LibWeb: Implement CharacterData.{append,insert,delete}Data

Userland/Libraries/LibWeb/DOM/CharacterData.cpp

@@ -103,4 +103,25 @@ ExceptionOr<void> CharacterData::replace_data(size_t offset, size_t count, Strin
     return {};
 }
 
+// https://dom.spec.whatwg.org/#dom-characterdata-appenddata
+ExceptionOr<void> CharacterData::append_data(String const& data)
+{
+    // The appendData(data) method steps are to replace data with node this, offset this’s length, count 0, and data data.
+    return replace_data(m_data.length(), 0, data);
+}
+
+// https://dom.spec.whatwg.org/#dom-characterdata-insertdata
+ExceptionOr<void> CharacterData::insert_data(size_t offset, String const& data)
+{
+    // The insertData(offset, data) method steps are to replace data with node this, offset offset, count 0, and data data.
+    return replace_data(offset, 0, data);
+}
+
+// https://dom.spec.whatwg.org/#dom-characterdata-deletedata
+ExceptionOr<void> CharacterData::delete_data(size_t offset, size_t count)
+{
+    // The deleteData(offset, count) method steps are to replace data with node this, offset offset, count count, and data the empty string.
+    return replace_data(offset, count, String::empty());
+}
+
 }

Userland/Libraries/LibWeb/DOM/CharacterData.h

@@ -28,6 +28,9 @@ public:
     unsigned length() const { return m_data.length(); }
 
     ExceptionOr<String> substring_data(size_t offset, size_t count) const;
+    ExceptionOr<void> append_data(String const&);
+    ExceptionOr<void> insert_data(size_t offset, String const&);
+    ExceptionOr<void> delete_data(size_t offset, size_t count);
     ExceptionOr<void> replace_data(size_t offset, size_t count, String const&);
 
 protected:

Userland/Libraries/LibWeb/DOM/CharacterData.idl

@@ -7,6 +7,9 @@ interface CharacterData : Node {
     readonly attribute unsigned long length;
 
     DOMString substringData(unsigned long offset, unsigned long count);
+    undefined appendData(DOMString data);
+    undefined insertData(unsigned long offset, DOMString data);
+    undefined deleteData(unsigned long offset, unsigned long count);
     undefined replaceData(unsigned long offset, unsigned long count, DOMString data);
 
     readonly attribute Element? nextElementSibling;