Auto merge of #19031 - cbrewster:push_replace_state_early, r=asajeffrey

Implement initial part of history.state

<!-- Please describe your changes on the following line: -->
Implements maintaining the current history state. Tracking history state in the session history will be done as a followup.

---
<!-- 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
- [ ] These changes fix #__ (github issue number if applicable).

<!-- Either: -->
- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19031)
<!-- Reviewable:end -->

1 files changed, 93 insertions, 1 deletions

diff --git a/components/script/dom/history.rs b/components/script/dom/history.rs
index 71e8c0c7e4e..17ee0d29cb6 100644
--- a/components/script/dom/history.rs
+++ b/components/script/dom/history.rs
@@ -10,25 +10,38 @@ use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::Castable;
 use dom::bindings::reflector::{Reflector, reflect_dom_object};
 use dom::bindings::root::{Dom, DomRoot};
+use dom::bindings::str::{DOMString, USVString};
+use dom::bindings::structuredclone::StructuredCloneData;
 use dom::globalscope::GlobalScope;
 use dom::window::Window;
 use dom_struct::dom_struct;
 use ipc_channel::ipc;
+use js::jsapi::{HandleValue, Heap, JSContext};
+use js::jsval::{JSVal, NullValue, UndefinedValue};
 use msg::constellation_msg::TraversalDirection;
 use script_traits::ScriptMsg;
 
+enum PushOrReplace {
+    Push,
+    Replace,
+}
+
 // https://html.spec.whatwg.org/multipage/#the-history-interface
 #[dom_struct]
 pub struct History {
     reflector_: Reflector,
     window: Dom<Window>,
+    state: Heap<JSVal>,
 }
 
 impl History {
     pub fn new_inherited(window: &Window) -> History {
+        let state = Heap::default();
+        state.set(NullValue());
         History {
             reflector_: Reflector::new(),
             window: Dom::from_ref(&window),
+            state: state,
         }
     }
 
@@ -48,9 +61,68 @@ impl History {
         let _ = self.window.upcast::<GlobalScope>().script_to_constellation_chan().send(msg);
         Ok(())
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-history-pushstate
+    // https://html.spec.whatwg.org/multipage/#dom-history-replacestate
+    fn push_or_replace_state(&self,
+                             cx: *mut JSContext,
+                             data: HandleValue,
+                             _title: DOMString,
+                             _url: Option<USVString>,
+                             _push_or_replace: PushOrReplace) -> ErrorResult {
+        // Step 1
+        let document = self.window.Document();
+
+        // Step 2
+        if !document.is_fully_active() {
+            return Err(Error::Security);
+        }
+
+        // TODO: Step 3 Optionally abort these steps
+        // https://github.com/servo/servo/issues/19159
+
+        // TODO: Step 4
+
+        // Step 5
+        let serialized_data = StructuredCloneData::write(cx, data)?;
+
+        // TODO: Steps 6-7 Url Handling
+        // https://github.com/servo/servo/issues/19157
+
+        // TODO: Step 8 Push/Replace session history entry
+        // https://github.com/servo/servo/issues/19156
+
+        // TODO: Step 9 Update current entry to represent a GET request
+        // https://github.com/servo/servo/issues/19156
+
+        // TODO: Step 10 Set document's URL to new URL
+        // https://github.com/servo/servo/issues/19157
+
+        // Step 11
+        let global_scope = self.window.upcast::<GlobalScope>();
+        rooted!(in(cx) let mut state = UndefinedValue());
+        serialized_data.read(&global_scope, state.handle_mut());
+
+        // Step 12
+        self.state.set(state.get());
+
+        // TODO: Step 13 Update Document's latest entry to current entry
+        // https://github.com/servo/servo/issues/19158
+
+        Ok(())
+    }
 }
 
 impl HistoryMethods for History {
+    // https://html.spec.whatwg.org/multipage/#dom-history-state
+    #[allow(unsafe_code)]
+    unsafe fn GetState(&self, _cx: *mut JSContext) -> Fallible<JSVal> {
+        if !self.window.Document().is_fully_active() {
+            return Err(Error::Security);
+        }
+        Ok(self.state.get())
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-history-length
     fn GetLength(&self) -> Fallible<u32> {
         if !self.window.Document().is_fully_active() {
@@ -60,7 +132,7 @@ impl HistoryMethods for History {
         let msg = ScriptMsg::JointSessionHistoryLength(sender);
         let _ = self.window.upcast::<GlobalScope>().script_to_constellation_chan().send(msg);
         Ok(recv.recv().unwrap())
-}
+    }
 
     // https://html.spec.whatwg.org/multipage/#dom-history-go
     fn Go(&self, delta: i32) -> ErrorResult {
@@ -84,4 +156,24 @@ impl HistoryMethods for History {
     fn Forward(&self) -> ErrorResult {
         self.traverse_history(TraversalDirection::Forward(1))
     }
+
+    // https://html.spec.whatwg.org/multipage/#dom-history-pushstate
+    #[allow(unsafe_code)]
+    unsafe fn PushState(&self,
+                        cx: *mut JSContext,
+                        data: HandleValue,
+                        title: DOMString,
+                        url: Option<USVString>) -> ErrorResult {
+        self.push_or_replace_state(cx, data, title, url, PushOrReplace::Push)
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-history-replacestate
+    #[allow(unsafe_code)]
+    unsafe fn ReplaceState(&self,
+                           cx: *mut JSContext,
+                           data: HandleValue,
+                           title: DOMString,
+                           url: Option<USVString>) -> ErrorResult {
+        self.push_or_replace_state(cx, data, title, url, PushOrReplace::Replace)
+    }
 }