LibWeb: Disallow editing API calls on non-HTML documents

This is not directly mentioned in the Editing API spec, but all major
browsers do this and there is a WPT for this behavior.

Libraries/LibWeb/DOM/Document.h

@@ -588,6 +588,13 @@ class Document
     bool query_command_supported(FlyString const& command);
     String query_command_value(FlyString const& command);
 
+    WebIDL::ExceptionOr<bool> exec_command_binding(FlyString const& command, bool show_ui, String const& value);
+    WebIDL::ExceptionOr<bool> query_command_enabled_binding(FlyString const& command);
+    WebIDL::ExceptionOr<bool> query_command_indeterm_binding(FlyString const& command);
+    WebIDL::ExceptionOr<bool> query_command_state_binding(FlyString const& command);
+    WebIDL::ExceptionOr<bool> query_command_supported_binding(FlyString const& command);
+    WebIDL::ExceptionOr<String> query_command_value_binding(FlyString const& command);
+
     // https://w3c.github.io/selection-api/#dfn-has-scheduled-selectionchange-event
     bool has_scheduled_selectionchange_event() const { return m_has_scheduled_selectionchange_event; }
     void set_scheduled_selectionchange_event(bool value) { m_has_scheduled_selectionchange_event = value; }

Libraries/LibWeb/DOM/Document.idl

@@ -144,12 +144,12 @@ interface Document : Node {
 
     // https://w3c.github.io/editing/docs/execCommand/
     // FIXME: [CEReactions] boolean execCommand(DOMString commandId, optional boolean showUI = false, optional (TrustedHTML or DOMString) value = "");
-    [CEReactions] boolean execCommand(DOMString commandId, optional boolean showUI = false, optional DOMString value = "");
-    boolean queryCommandEnabled(DOMString commandId);
-    boolean queryCommandIndeterm(DOMString commandId);
-    boolean queryCommandState(DOMString commandId);
-    boolean queryCommandSupported(DOMString commandId);
-    DOMString queryCommandValue(DOMString commandId);
+    [CEReactions, ImplementedAs=exec_command_binding] boolean execCommand(DOMString commandId, optional boolean showUI = false, optional DOMString value = "");
+    [ImplementedAs=query_command_enabled_binding] boolean queryCommandEnabled(DOMString commandId);
+    [ImplementedAs=query_command_indeterm_binding] boolean queryCommandIndeterm(DOMString commandId);
+    [ImplementedAs=query_command_state_binding] boolean queryCommandState(DOMString commandId);
+    [ImplementedAs=query_command_supported_binding] boolean queryCommandSupported(DOMString commandId);
+    [ImplementedAs=query_command_value_binding] DOMString queryCommandValue(DOMString commandId);
 
     // special event handler IDL attributes that only apply to Document objects
     [LegacyLenientThis] attribute EventHandler onreadystatechange;

Libraries/LibWeb/Editing/ExecCommand.cpp

@@ -13,6 +13,15 @@
 
 namespace Web::DOM {
 
+WebIDL::ExceptionOr<bool> Document::exec_command_binding(FlyString const& command, bool show_ui, String const& value)
+{
+    // AD-HOC: This is not directly mentioned in the spec, but all major browsers limit editing API calls to HTML documents
+    if (!is_html_document())
+        return WebIDL::InvalidStateError::create(realm(), "execCommand is only supported on HTML documents"_string);
+
+    return exec_command(command, show_ui, value);
+}
+
 // https://w3c.github.io/editing/docs/execCommand/#execcommand()
 bool Document::exec_command(FlyString const& command, [[maybe_unused]] bool show_ui, String const& value)
 {
@@ -98,6 +107,15 @@ bool Document::exec_command(FlyString const& command, [[maybe_unused]] bool show
     return true;
 }
 
+WebIDL::ExceptionOr<bool> Document::query_command_enabled_binding(FlyString const& command)
+{
+    // AD-HOC: This is not directly mentioned in the spec, but all major browsers limit editing API calls to HTML documents
+    if (!is_html_document())
+        return WebIDL::InvalidStateError::create(realm(), "queryCommandEnabled is only supported on HTML documents"_string);
+
+    return query_command_enabled(command);
+}
+
 // https://w3c.github.io/editing/docs/execCommand/#querycommandenabled()
 bool Document::query_command_enabled(FlyString const& command)
 {
@@ -178,6 +196,15 @@ bool Document::query_command_enabled(FlyString const& command)
     return true;
 }
 
+WebIDL::ExceptionOr<bool> Document::query_command_indeterm_binding(FlyString const& command)
+{
+    // AD-HOC: This is not directly mentioned in the spec, but all major browsers limit editing API calls to HTML documents
+    if (!is_html_document())
+        return WebIDL::InvalidStateError::create(realm(), "queryCommandIndeterm is only supported on HTML documents"_string);
+
+    return query_command_indeterm(command);
+}
+
 // https://w3c.github.io/editing/docs/execCommand/#querycommandindeterm()
 bool Document::query_command_indeterm(FlyString const& command)
 {
@@ -250,6 +277,15 @@ bool Document::query_command_indeterm(FlyString const& command)
     return command_definition.indeterminate(*this);
 }
 
+WebIDL::ExceptionOr<bool> Document::query_command_state_binding(FlyString const& command)
+{
+    // AD-HOC: This is not directly mentioned in the spec, but all major browsers limit editing API calls to HTML documents
+    if (!is_html_document())
+        return WebIDL::InvalidStateError::create(realm(), "queryCommandState is only supported on HTML documents"_string);
+
+    return query_command_state(command);
+}
+
 // https://w3c.github.io/editing/docs/execCommand/#querycommandstate()
 bool Document::query_command_state(FlyString const& command)
 {
@@ -292,6 +328,15 @@ bool Document::query_command_state(FlyString const& command)
     return command_definition.state(*this);
 }
 
+WebIDL::ExceptionOr<bool> Document::query_command_supported_binding(FlyString const& command)
+{
+    // AD-HOC: This is not directly mentioned in the spec, but all major browsers limit editing API calls to HTML documents
+    if (!is_html_document())
+        return WebIDL::InvalidStateError::create(realm(), "queryCommandSupported is only supported on HTML documents"_string);
+
+    return query_command_supported(command);
+}
+
 // https://w3c.github.io/editing/docs/execCommand/#querycommandsupported()
 bool Document::query_command_supported(FlyString const& command)
 {
@@ -301,6 +346,15 @@ bool Document::query_command_supported(FlyString const& command)
     return Editing::find_command_definition(command).has_value();
 }
 
+WebIDL::ExceptionOr<String> Document::query_command_value_binding(FlyString const& command)
+{
+    // AD-HOC: This is not directly mentioned in the spec, but all major browsers limit editing API calls to HTML documents
+    if (!is_html_document())
+        return WebIDL::InvalidStateError::create(realm(), "queryCommandValue is only supported on HTML documents"_string);
+
+    return query_command_value(command);
+}
+
 // https://w3c.github.io/editing/docs/execCommand/#querycommandvalue()
 String Document::query_command_value(FlyString const& command)
 {

Tests/LibWeb/Text/expected/Editing/execCommand-selectAll.txt

@@ -3,5 +3,4 @@ DIV 0 - DIV 0
 BODY 0 - BODY 5
 true
 false
-false
 Did not crash!

Tests/LibWeb/Text/expected/wpt-import/editing/other/non-html-document.txt

@@ -0,0 +1,6 @@
+Harness status: OK
+
+Found 1 tests
+
+1 Pass
+Pass	editing APIs on an XML document should be disabled

Tests/LibWeb/Text/input/Editing/execCommand-selectAll.html

@@ -37,7 +37,6 @@
         // Report whether command is enabled and make sure it does not crash
         const documents = [
             document,
-            new Document(),
             document.implementation.createHTMLDocument(),
         ];
         for (const doc of documents) {

Tests/LibWeb/Text/input/wpt-import/editing/other/non-html-document.html

@@ -0,0 +1,24 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>Non-HTML document tests</title>
+<script src=../../resources/testharness.js></script>
+<script src=../../resources/testharnessreport.js></script>
+<script>
+
+test(function() {
+  let xmldoc =
+    document.implementation.createDocument("http://www.w3.org/1999/xlink",
+                                           "html", null);
+  for (let f of [
+         () => xmldoc.execCommand("bold"),
+         () => xmldoc.queryCommandEnabled("bold"),
+         () => xmldoc.queryCommandIndeterm("bold"),
+         () => xmldoc.queryCommandState("bold"),
+         () => xmldoc.queryCommandSupported("bold"),
+         () => xmldoc.queryCommandValue("bold"),
+       ]) {
+    assert_throws_dom("InvalidStateError", f);
+  }
+}, "editing APIs on an XML document should be disabled");
+
+</script>