Auto merge of #24220 - rasviitanen:domstringlist, r=jdm

add webidl bindings for DOMStringList

<!-- Please describe your changes on the following line: -->
To prepare for the implementation of `IndexedDB` a DOM interface for `DOMStringList` is added.

This change:
* Adds a new IDL file for `DOMStringList`
* Lists `domstringlist.rs` in `mod.rs`
* Defines a new DOMStruct `DOMStringList`
* Changes some test expectations related to `DOMStringList`
---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #24208

- [X] These changes do not require tests because:
We are not yet able to fully test the functions of `DOMStringList` in the WPT, because it is not possible to create an object of the type `DOMStringList` until e.g. `indexeddb` or `location.ancestorOrigins` is implemented.

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components/script/dom/domstringlist.rs

@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use crate::dom::bindings::codegen::Bindings::DOMStringListBinding;
+use crate::dom::bindings::codegen::Bindings::DOMStringListBinding::DOMStringListMethods;
+use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::window::Window;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct DOMStringList {
+    reflector_: Reflector,
+    strings: Vec<DOMString>,
+}
+
+impl DOMStringList {
+    #[allow(unused)]
+    pub fn new_inherited(strings: Vec<DOMString>) -> DOMStringList {
+        DOMStringList {
+            reflector_: Reflector::new(),
+            strings,
+        }
+    }
+
+    #[allow(unused)]
+    pub fn new(window: &Window, strings: Vec<DOMString>) -> DomRoot<DOMStringList> {
+        reflect_dom_object(
+            Box::new(DOMStringList::new_inherited(strings)),
+            window,
+            DOMStringListBinding::Wrap,
+        )
+    }
+}
+
+// https://html.spec.whatwg.org/multipage/#domstringlist
+impl DOMStringListMethods for DOMStringList {
+    // https://html.spec.whatwg.org/multipage/#dom-domstringlist-length
+    fn Length(&self) -> u32 {
+        self.strings.len() as u32
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-domstringlist-item
+    fn Item(&self, index: u32) -> Option<DOMString> {
+        self.strings.get(index as usize).cloned()
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-domstringlist-contains
+    fn Contains(&self, string: DOMString) -> bool {
+        self.strings.contains(&string)
+    }
+
+    // check-tidy: no specs after this line
+    fn IndexedGetter(&self, index: u32) -> Option<DOMString> {
+        self.Item(index)
+    }
+}

components/script/dom/mod.rs

@@ -293,6 +293,7 @@ pub mod dompointreadonly;
 pub mod domquad;
 pub mod domrect;
 pub mod domrectreadonly;
+pub mod domstringlist;
 pub mod domstringmap;
 pub mod domtokenlist;
 pub mod element;

components/script/dom/webidls/DOMStringList.webidl

@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+/*
+ * The origin of this IDL file is
+ * https://html.spec.whatwg.org/multipage/#domstringlist
+ *
+ * Copyright:
+ * To the extent possible under law, the editors have waived all copyright and
+ * related or neighboring rights to this work.
+ */
+
+[Exposed=(Window,Worker)]
+interface DOMStringList {
+  readonly attribute unsigned long length;
+  getter DOMString? item(unsigned long index);
+  boolean contains(DOMString string);
+};