From 7c2abb9d579d13fa61339c24f8c39bc3c27c25db Mon Sep 17 00:00:00 2001
From: Ryan Dahl <ry@tinyclouds.org>
Date: Wed, 3 Nov 2021 09:27:36 -0400
Subject: [PATCH] fix: Deno.emit crashes with BorrowMutError (#12627)

Warn on await_holding_refcell_ref clippy rule to avoid this in the future.

Fixes #12453
---
 cli/ops/runtime_compiler.rs        | 12 +++++++++---
 cli/tests/integration/run_tests.rs | 18 ++++++++++++++++++
 cli/tests/testdata/issue12453.js   |  4 ++++
 core/runtime.rs                    |  9 ++++++---
 ext/web/message_port.rs            |  1 +
 runtime/web_worker.rs              |  1 +
 tools/lint.js                      |  9 ++++++++-
 7 files changed, 47 insertions(+), 7 deletions(-)
 create mode 100644 cli/tests/testdata/issue12453.js

diff --git a/cli/ops/runtime_compiler.rs b/cli/ops/runtime_compiler.rs
index ab6992d19c..8f7a75146d 100644
--- a/cli/ops/runtime_compiler.rs
+++ b/cli/ops/runtime_compiler.rs
@@ -88,9 +88,15 @@ async fn op_emit(
 ) -> Result<EmitResult, AnyError> {
   deno_runtime::ops::check_unstable2(&state, "Deno.emit");
   let root_specifier = args.root_specifier;
-  let state = state.borrow();
-  let ps = state.borrow::<ProcState>();
-  let mut runtime_permissions = { state.borrow::<Permissions>().clone() };
+  let ps = {
+    let state = state.borrow();
+    state.borrow::<ProcState>().clone()
+  };
+  let mut runtime_permissions = {
+    let state = state.borrow();
+    state.borrow::<Permissions>().clone()
+  };
+
   let mut cache: Box<dyn cache::CacherLoader> =
     if let Some(sources) = &args.sources {
       Box::new(cache::MemoryCacher::new(sources.clone()))
diff --git a/cli/tests/integration/run_tests.rs b/cli/tests/integration/run_tests.rs
index ec42a8dc8f..b7480c44b1 100644
--- a/cli/tests/integration/run_tests.rs
+++ b/cli/tests/integration/run_tests.rs
@@ -2148,3 +2148,21 @@ itest!(eval_context_throw_dom_exception {
   args: "run eval_context_throw_dom_exception.js",
   output: "eval_context_throw_dom_exception.js.out",
 });
+
+#[test]
+fn issue12453() {
+  let _g = util::http_server();
+  let deno_dir = util::new_deno_dir();
+  let mut deno_cmd = util::deno_cmd_with_deno_dir(deno_dir.path());
+  let status = deno_cmd
+    .current_dir(util::testdata_path())
+    .arg("run")
+    .arg("--unstable")
+    .arg("--allow-net")
+    .arg("issue12453.js")
+    .spawn()
+    .unwrap()
+    .wait()
+    .unwrap();
+  assert!(status.success());
+}
diff --git a/cli/tests/testdata/issue12453.js b/cli/tests/testdata/issue12453.js
new file mode 100644
index 0000000000..2ed1b5ae74
--- /dev/null
+++ b/cli/tests/testdata/issue12453.js
@@ -0,0 +1,4 @@
+const i = setInterval(() => {
+  Deno.emit("http://localhost:4545/subdir/mt_text_typescript.t1.ts");
+  clearInterval(i);
+}, 1);
diff --git a/core/runtime.rs b/core/runtime.rs
index 80221295da..704be7a769 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -2317,11 +2317,14 @@ assertEquals(1, notify_return_value);
       _: (),
       _: (),
     ) -> Result<(), AnyError> {
-      let op_state = op_state.borrow();
-      let inner_state = op_state.borrow::<InnerState>();
+      let n = {
+        let op_state = op_state.borrow();
+        let inner_state = op_state.borrow::<InnerState>();
+        inner_state.0
+      };
       // Future must be Poll::Pending on first call
       tokio::time::sleep(std::time::Duration::from_millis(1)).await;
-      if inner_state.0 != 42 {
+      if n != 42 {
         unreachable!();
       }
       Ok(())
diff --git a/ext/web/message_port.rs b/ext/web/message_port.rs
index d8d8e5907d..8734f9b65c 100644
--- a/ext/web/message_port.rs
+++ b/ext/web/message_port.rs
@@ -48,6 +48,7 @@ impl MessagePort {
     &self,
     state: Rc<RefCell<OpState>>,
   ) -> Result<Option<JsMessageData>, AnyError> {
+    #![allow(clippy::await_holding_refcell_ref)] // TODO(ry) remove!
     let mut rx = self
       .rx
       .try_borrow_mut()
diff --git a/runtime/web_worker.rs b/runtime/web_worker.rs
index 8d3fcbb35a..c70d20ffcf 100644
--- a/runtime/web_worker.rs
+++ b/runtime/web_worker.rs
@@ -198,6 +198,7 @@ impl WebWorkerHandle {
   pub async fn get_control_event(
     &self,
   ) -> Result<Option<WorkerControlEvent>, AnyError> {
+    #![allow(clippy::await_holding_refcell_ref)] // TODO(ry) remove!
     let mut receiver = self.receiver.borrow_mut();
     Ok(receiver.next().await)
   }
diff --git a/tools/lint.js b/tools/lint.js
index 03339bcbe4..bcb181e291 100755
--- a/tools/lint.js
+++ b/tools/lint.js
@@ -109,7 +109,14 @@ async function clippy() {
   }
 
   const p = Deno.run({
-    cmd: [...cmd, "--", "-D", "clippy::all"],
+    cmd: [
+      ...cmd,
+      "--",
+      "-D",
+      "clippy::all",
+      "-D",
+      "clippy::await_holding_refcell_ref",
+    ],
   });
   const { success } = await p.status();
   if (!success) {