implement abort algorithm for stream piping

Signed-off-by: gterzian <2792687+gterzian@users.noreply.github.com>

components/script/dom/abortsignal.rs

@@ -18,7 +18,7 @@ use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::readablestream::PipeTo;
-use crate::script_runtime::{CanGc, JSContext};
+use crate::script_runtime::{CanGc, JSContext as SafeJSContext};
 
 impl js::gc::Rootable for AbortAlgorithm {}
 
@@ -73,7 +73,9 @@ impl AbortSignal {
     }
 
     /// <https://dom.spec.whatwg.org/#abortsignal-signal-abort>
-    pub(crate) fn signal_abort(&self, cx: JSContext, reason: HandleValue, can_gc: CanGc) {
+    pub(crate) fn signal_abort(&self, cx: SafeJSContext, reason: HandleValue, can_gc: CanGc) {
+        let global = self.global();
+
         // If signal is aborted, then return.
         if self.Aborted() {
             return;
@@ -87,7 +89,7 @@ impl AbortSignal {
         } else {
             // otherwise to a new "AbortError" DOMException.
             rooted!(in(*cx) let mut rooted_error = UndefinedValue());
-            Error::Abort.to_jsval(cx, &self.global(), rooted_error.handle_mut(), can_gc);
+            Error::Abort.to_jsval(cx, &global, rooted_error.handle_mut(), can_gc);
             self.abort_reason.set(rooted_error.get())
         }
 
@@ -96,7 +98,7 @@ impl AbortSignal {
         // TODO: #36936
 
         // Run the abort steps for signal.
-        self.run_the_abort_steps(can_gc);
+        self.run_the_abort_steps(cx, &global, can_gc);
 
         // For each dependentSignal of dependentSignalsToAbort, run the abort steps for dependentSignal.
         // TODO: #36936
@@ -114,17 +116,26 @@ impl AbortSignal {
     }
 
     /// Run a specific abort algorithm.
-    pub(crate) fn run_abort_algorithm(&self, algorithm: &AbortAlgorithm) {
-        // TODO: match on variant and implement algo steps.
-        // See the various items of #34866
+    pub(crate) fn run_abort_algorithm(&self, cx: SafeJSContext, global: &GlobalScope, algorithm: &AbortAlgorithm, can_gc: CanGc) {
+        match algorithm {
+            AbortAlgorithm::StreamPiping(pipe) => {
+                rooted!(in(*cx) let mut reason = UndefinedValue());
+                reason.set(self.abort_reason.get());
+                pipe.abort_with_reason(cx, global, reason.handle(), can_gc);
+            },
+            _ => {
+                // TODO: match on variant and implement algo steps.
+                // See the various items of #34866
+            }
+        }
     }
 
     /// <https://dom.spec.whatwg.org/#run-the-abort-steps>
-    fn run_the_abort_steps(&self, can_gc: CanGc) {
+    fn run_the_abort_steps(&self, cx: SafeJSContext, global: &GlobalScope, can_gc: CanGc) {
         // For each algorithm of signal’s abort algorithms: run algorithm.
         let algos = mem::take(&mut *self.abort_algorithms.borrow_mut());
         for algo in algos {
-            self.run_abort_algorithm(&algo);
+            self.run_abort_algorithm(cx, global, &algo, can_gc);
         }
 
         // Empty signal’s abort algorithms.
@@ -150,7 +161,7 @@ impl AbortSignalMethods<crate::DomTypeHolder> for AbortSignal {
     }
 
     /// <https://dom.spec.whatwg.org/#dom-abortsignal-reason>
-    fn Reason(&self, _cx: JSContext, mut rval: MutableHandleValue) {
+    fn Reason(&self, _cx: SafeJSContext, mut rval: MutableHandleValue) {
         // The reason getter steps are to return this’s abort reason.
         rval.set(self.abort_reason.get());
     }

components/script/dom/readablestream.rs

@@ -161,6 +161,63 @@ pub(crate) struct PipeTo {
     result_promise: Rc<Promise>,
 }
 
+impl PipeTo {
+    /// Run the `abortAlgorithm` defined at
+    /// <https://streams.spec.whatwg.org/#readable-stream-pipe-to>
+    pub(crate) fn abort_with_reason(&self, cx: SafeJSContext, global: &GlobalScope, error: SafeHandleValue, can_gc: CanGc) {
+        // Let error be signal’s abort reason.
+        // Note: passed as the `reason` argument.
+
+        // Let actions be an empty ordered set.
+        let mut actions = vec![];
+
+        // If preventAbort is false, append the following action to actions:
+        if !self.prevent_abort {
+            let dest = self
+                    .writer
+                    .get_stream()
+                    .expect("Destination stream must be set");
+            
+            // If dest.[[state]] is "writable",
+            let promise = if dest.is_writable() {
+                // return ! WritableStreamAbort(dest, error)
+                dest.abort(cx, global, error, can_gc)
+            } else {
+                // Otherwise, return a promise resolved with undefined.
+                Promise::new_resolved(
+                    global,
+                    cx,
+                    &(),
+                    can_gc,
+                )
+            };
+            actions.push(promise);
+        }
+
+        // If preventCancel is false, append the following action action to actions:
+        if !self.prevent_cancel {
+            let source = self.reader.get_stream().expect("Source stream must be set");
+
+            // If source.[[state]] is "readable", 
+            let promise = if source.is_readable() {
+                // return ! ReadableStreamCancel(source, error).
+                source.cancel(cx, global, error, can_gc)
+            } else {
+                // Otherwise, return a promise resolved with undefined.
+                Promise::new_resolved(
+                    global,
+                    cx,
+                    &(),
+                    can_gc,
+                )
+            };
+            actions.push(promise);
+        }
+
+        // Shutdown with an action consisting of getting a promise to wait for all of the actions in actions, and with error.
+    }
+}
+
 impl Callback for PipeTo {
     /// The pipe makes progress one microtask at a time.
     /// Note: we use one struct as the callback for all promises,
@@ -1713,7 +1770,7 @@ impl ReadableStream {
 
             // If signal is aborted, perform abortAlgorithm and return promise.
             if signal.aborted() {
-                signal.run_abort_algorithm(&abort_algorithm);
+                signal.run_abort_algorithm(cx, global, &abort_algorithm, can_gc);
                 return promise;
             }