Implement `ShadowRoot.innerHtml` attribute (#34335)

* Implement DocumentFragment::fragment_serialization_algorithm

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

* Implement ShadowRoot innerHtml attribute

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

* Update WPT expectations

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

* cargo-clippy

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

* Reuse existing serialization code and move helpers into Node

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

* Fix typo

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

---------

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

6 files changed, 110 insertions, 53 deletions

diff --git a/components/script/dom/bindings/codegen/Bindings.conf b/components/script/dom/bindings/codegen/Bindings.conf
index 27bbc202f22..48d9392465f 100644
--- a/components/script/dom/bindings/codegen/Bindings.conf
+++ b/components/script/dom/bindings/codegen/Bindings.conf
@@ -420,7 +420,7 @@ DOMInterfaces = {
 },
 
 'ShadowRoot': {
-    'canGc': ['ElementFromPoint', 'ElementsFromPoint'],
+    'canGc': ['ElementFromPoint', 'ElementsFromPoint', 'SetInnerHTML'],
 },
 
 'StaticRange': {
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 1c6d22c979a..41aec11ca90 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -18,10 +18,8 @@ use dom_struct::dom_struct;
 use embedder_traits::InputMethodType;
 use euclid::default::{Rect, Size2D};
 use html5ever::serialize::TraversalScope::{ChildrenOnly, IncludeNode};
-use html5ever::serialize::{SerializeOpts, TraversalScope};
 use html5ever::{
-    local_name, namespace_prefix, namespace_url, ns, serialize, LocalName, Namespace, Prefix,
-    QualName,
+    local_name, namespace_prefix, namespace_url, ns, LocalName, Namespace, Prefix, QualName,
 };
 use js::jsapi::Heap;
 use js::jsval::JSVal;
@@ -61,11 +59,9 @@ use style::values::generics::NonNegative;
 use style::values::{computed, specified, AtomIdent, AtomString, CSSFloat};
 use style::{dom_apis, thread_state, ArcSlice, CaseSensitivityExt};
 use style_dom::ElementState;
-use xml5ever::serialize as xmlSerialize;
 use xml5ever::serialize::TraversalScope::{
     ChildrenOnly as XmlChildrenOnly, IncludeNode as XmlIncludeNode,
 };
-use xml5ever::serialize::{SerializeOpts as XmlSerializeOpts, TraversalScope as XmlTraversalScope};
 
 use super::htmltablecolelement::{HTMLTableColElement, HTMLTableColElementLayoutHelpers};
 use crate::dom::activation::Activatable;
@@ -1327,35 +1323,6 @@ impl Element {
         }
     }
 
-    pub fn serialize(&self, traversal_scope: TraversalScope) -> Fallible<DOMString> {
-        let mut writer = vec![];
-        match serialize(
-            &mut writer,
-            &self.upcast::<Node>(),
-            SerializeOpts {
-                traversal_scope,
-                ..Default::default()
-            },
-        ) {
-            // FIXME(ajeffrey): Directly convert UTF8 to DOMString
-            Ok(()) => Ok(DOMString::from(String::from_utf8(writer).unwrap())),
-            Err(_) => panic!("Cannot serialize element"),
-        }
-    }
-
-    #[allow(non_snake_case)]
-    pub fn xmlSerialize(&self, traversal_scope: XmlTraversalScope) -> Fallible<DOMString> {
-        let mut writer = vec![];
-        match xmlSerialize::serialize(
-            &mut writer,
-            &self.upcast::<Node>(),
-            XmlSerializeOpts { traversal_scope },
-        ) {
-            Ok(()) => Ok(DOMString::from(String::from_utf8(writer).unwrap())),
-            Err(_) => panic!("Cannot serialize element"),
-        }
-    }
-
     pub fn root_element(&self) -> DomRoot<Element> {
         if self.node.is_in_doc() {
             self.upcast::<Node>()
@@ -1959,7 +1926,7 @@ impl Element {
         win.scroll_node(node, x, y, behavior, can_gc);
     }
 
-    // https://w3c.github.io/DOM-Parsing/#parsing
+    /// <https://html.spec.whatwg.org/multipage/#fragment-parsing-algorithm-steps>
     pub fn parse_fragment(
         &self,
         markup: DOMString,
@@ -2743,21 +2710,26 @@ impl ElementMethods for Element {
         self.client_rect(can_gc).size.height
     }
 
-    /// <https://w3c.github.io/DOM-Parsing/#widl-Element-innerHTML>
+    /// <https://html.spec.whatwg.org/multipage/#dom-element-innerhtml>
     fn GetInnerHTML(&self) -> Fallible<DOMString> {
         let qname = QualName::new(
             self.prefix().clone(),
             self.namespace().clone(),
             self.local_name().clone(),
         );
-        if document_from_node(self).is_html_document() {
-            self.serialize(ChildrenOnly(Some(qname)))
+
+        let result = if document_from_node(self).is_html_document() {
+            self.upcast::<Node>()
+                .html_serialize(ChildrenOnly(Some(qname)))
         } else {
-            self.xmlSerialize(XmlChildrenOnly(Some(qname)))
-        }
+            self.upcast::<Node>()
+                .xml_serialize(XmlChildrenOnly(Some(qname)))
+        };
+
+        Ok(result)
     }
 
-    /// <https://w3c.github.io/DOM-Parsing/#widl-Element-innerHTML>
+    /// <https://html.spec.whatwg.org/multipage/#dom-element-innerhtml>
     fn SetInnerHTML(&self, value: DOMString, can_gc: CanGc) -> ErrorResult {
         // Step 2.
         // https://github.com/w3c/DOM-Parsing/issues/1
@@ -2787,16 +2759,18 @@ impl ElementMethods for Element {
         Ok(())
     }
 
-    // https://dvcs.w3.org/hg/innerhtml/raw-file/tip/index.html#widl-Element-outerHTML
+    /// <https://html.spec.whatwg.org/multipage/#dom-element-outerhtml>
     fn GetOuterHTML(&self) -> Fallible<DOMString> {
-        if document_from_node(self).is_html_document() {
-            self.serialize(IncludeNode)
+        let result = if document_from_node(self).is_html_document() {
+            self.upcast::<Node>().html_serialize(IncludeNode)
         } else {
-            self.xmlSerialize(XmlIncludeNode)
-        }
+            self.upcast::<Node>().xml_serialize(XmlIncludeNode)
+        };
+
+        Ok(result)
     }
 
-    // https://w3c.github.io/DOM-Parsing/#dom-element-outerhtml
+    /// <https://html.spec.whatwg.org/multipage/#dom-element-outerhtml>
     fn SetOuterHTML(&self, value: DOMString, can_gc: CanGc) -> ErrorResult {
         let context_document = document_from_node(self);
         let context_node = self.upcast::<Node>();
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index 3267204fda4..a102682d8c6 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -18,7 +18,7 @@ use bitflags::bitflags;
 use devtools_traits::NodeInfo;
 use dom_struct::dom_struct;
 use euclid::default::{Rect, Size2D, Vector2D};
-use html5ever::{namespace_url, ns, Namespace, Prefix, QualName};
+use html5ever::{namespace_url, ns, serialize as html_serialize, Namespace, Prefix, QualName};
 use js::jsapi::JSObject;
 use js::rust::HandleObject;
 use libc::{self, c_void, uintptr_t};
@@ -43,6 +43,7 @@ use style::properties::ComputedValues;
 use style::selector_parser::{SelectorImpl, SelectorParser};
 use style::stylesheets::{Stylesheet, UrlExtraData};
 use uuid::Uuid;
+use xml5ever::serialize as xml_serialize;
 
 use crate::document_loader::DocumentLoader;
 use crate::dom::attr::Attr;
@@ -2448,6 +2449,52 @@ impl Node {
         }
         &*(conversions::private_from_object(object) as *const Self)
     }
+
+    pub fn html_serialize(&self, traversal_scope: html_serialize::TraversalScope) -> DOMString {
+        let mut writer = vec![];
+        html_serialize::serialize(
+            &mut writer,
+            &self,
+            html_serialize::SerializeOpts {
+                traversal_scope,
+                ..Default::default()
+            },
+        )
+        .expect("Cannot serialize node");
+
+        // FIXME(ajeffrey): Directly convert UTF8 to DOMString
+        DOMString::from(String::from_utf8(writer).unwrap())
+    }
+
+    pub fn xml_serialize(&self, traversal_scope: xml_serialize::TraversalScope) -> DOMString {
+        let mut writer = vec![];
+        xml_serialize::serialize(
+            &mut writer,
+            &self,
+            xml_serialize::SerializeOpts { traversal_scope },
+        )
+        .expect("Cannot serialize node");
+
+        // FIXME(ajeffrey): Directly convert UTF8 to DOMString
+        DOMString::from(String::from_utf8(writer).unwrap())
+    }
+
+    /// <https://html.spec.whatwg.org/multipage/#fragment-serializing-algorithm-steps>
+    pub fn fragment_serialization_algorithm(&self, require_well_formed: bool) -> DOMString {
+        // Step 1. Let context document be node's node document.
+        let context_document = document_from_node(self);
+
+        // Step 2. If context document is an HTML document, return the result of HTML fragment serialization algorithm
+        // with node, false, and « ».
+        if context_document.is_html_document() {
+            return self.html_serialize(html_serialize::TraversalScope::ChildrenOnly(None));
+        }
+
+        // Step 3. Return the XML serialization of node given require well-formed.
+        // TODO: xml5ever doesn't seem to want require_well_formed
+        let _ = require_well_formed;
+        self.xml_serialize(xml_serialize::TraversalScope::ChildrenOnly(None))
+    }
 }
 
 impl NodeMethods for Node {
diff --git a/components/script/dom/shadowroot.rs b/components/script/dom/shadowroot.rs
index 22967bb5ad2..d7810806864 100644
--- a/components/script/dom/shadowroot.rs
+++ b/components/script/dom/shadowroot.rs
@@ -18,6 +18,7 @@ use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::num::Finite;
 use crate::dom::bindings::reflector::reflect_dom_object;
 use crate::dom::bindings::root::{Dom, DomRoot, LayoutDom, MutNullableDom};
+use crate::dom::bindings::str::DOMString;
 use crate::dom::cssstylesheet::CSSStyleSheet;
 use crate::dom::document::Document;
 use crate::dom::documentfragment::DocumentFragment;
@@ -249,6 +250,34 @@ impl ShadowRootMethods for ShadowRoot {
             )
         })
     }
+
+    /// <https://html.spec.whatwg.org/multipage/#dom-shadowroot-innerhtml>
+    fn InnerHTML(&self) -> DOMString {
+        // ShadowRoot's innerHTML getter steps are to return the result of running fragment serializing
+        // algorithm steps with this and true.
+        self.upcast::<Node>().fragment_serialization_algorithm(true)
+    }
+
+    /// <https://html.spec.whatwg.org/multipage/#dom-shadowroot-innerhtml>
+    fn SetInnerHTML(&self, value: DOMString, can_gc: CanGc) {
+        // TODO Step 1. Let compliantString be the result of invoking the Get Trusted Type compliant string algorithm
+        // with TrustedHTML, this's relevant global object, the given value, "ShadowRoot innerHTML", and "script".
+        let compliant_string = value;
+
+        // Step 2. Let context be this's host.
+        let context = self.Host();
+
+        // Step 3. Let fragment be the result of invoking the fragment parsing algorithm steps with context and
+        // compliantString.
+        let Ok(frag) = context.parse_fragment(compliant_string, can_gc) else {
+            // NOTE: The spec doesn't strictly tell us to bail out here, but
+            // we can't continue if parsing failed
+            return;
+        };
+
+        // Step 4. Replace all with fragment within this.
+        Node::replace_all(Some(frag.upcast()), self.upcast());
+    }
 }
 
 #[allow(unsafe_code)]
diff --git a/components/script/dom/webidls/Element.webidl b/components/script/dom/webidls/Element.webidl
index 4525e4ae9c8..99d17117221 100644
--- a/components/script/dom/webidls/Element.webidl
+++ b/components/script/dom/webidls/Element.webidl
@@ -121,10 +121,8 @@ partial interface Element {
 
 // https://w3c.github.io/DOM-Parsing/#extensions-to-the-element-interface
 partial interface Element {
-  [CEReactions, Throws]
-  attribute [LegacyNullToEmptyString] DOMString innerHTML;
-  [CEReactions, Throws]
-  attribute [LegacyNullToEmptyString] DOMString outerHTML;
+  [CEReactions, Throws] attribute [LegacyNullToEmptyString] DOMString innerHTML;
+  [CEReactions, Throws] attribute [LegacyNullToEmptyString] DOMString outerHTML;
 };
 
 // https://fullscreen.spec.whatwg.org/#api
diff --git a/components/script/dom/webidls/ShadowRoot.webidl b/components/script/dom/webidls/ShadowRoot.webidl
index c8f3e754016..a1ecdc5c10f 100644
--- a/components/script/dom/webidls/ShadowRoot.webidl
+++ b/components/script/dom/webidls/ShadowRoot.webidl
@@ -16,3 +16,12 @@ enum ShadowRootMode { "open", "closed"};
 // enum SlotAssignmentMode { "manual", "named" };
 
 ShadowRoot includes DocumentOrShadowRoot;
+
+// https://html.spec.whatwg.org/multipage/#dom-parsing-and-serialization
+partial interface ShadowRoot {
+  // [CEReactions] undefined setHTMLUnsafe((TrustedHTML or DOMString) html);
+  // DOMString getHTML(optional GetHTMLOptions options = {});
+
+  // [CEReactions] attribute (TrustedHTML or [LegacyNullToEmptyString] DOMString) innerHTML;
+  [CEReactions] attribute [LegacyNullToEmptyString] DOMString innerHTML;
+};