From f46aa1f67ac078dd67a1ef894aa4866724472697 Mon Sep 17 00:00:00 2001
From: LongYinan <lynweklm@gmail.com>
Date: Mon, 25 Jan 2021 11:46:58 +0800
Subject: [PATCH] fix(napi): throw JavaScript error in tsfn rather than rust
 thread panic

---
 napi/src/threadsafe_function.rs               | 45 ++++++++++++++++++-
 .../napi4/threadsafe_function.spec.ts         | 14 ++++++
 test_module/__test__/napi4/tsfn-throw.js      |  5 +++
 3 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 test_module/__test__/napi4/tsfn-throw.js

diff --git a/napi/src/threadsafe_function.rs b/napi/src/threadsafe_function.rs
index 81c70c09..f60dd8f4 100644
--- a/napi/src/threadsafe_function.rs
+++ b/napi/src/threadsafe_function.rs
@@ -302,5 +302,48 @@ unsafe extern "C" fn call_js_cb<T: 'static, V: NapiValue>(
       );
     }
   }
-  debug_assert!(status == sys::Status::napi_ok, "CallJsCB failed");
+  if status == sys::Status::napi_pending_exception {
+    let mut error_result = ptr::null_mut();
+    assert_eq!(
+      sys::napi_get_and_clear_last_exception(raw_env, &mut error_result),
+      sys::Status::napi_ok
+    );
+    assert_eq!(
+      sys::napi_fatal_exception(raw_env, error_result),
+      sys::Status::napi_ok
+    );
+  } else if status != sys::Status::napi_ok {
+    let error_code: Status = status.into();
+    let error_code_string = format!("{:?}", error_code);
+    let mut error_code_value = ptr::null_mut();
+    assert_eq!(
+      sys::napi_create_string_utf8(
+        raw_env,
+        error_code_string.as_ptr() as *const _,
+        error_code_string.len(),
+        &mut error_code_value
+      ),
+      sys::Status::napi_ok,
+    );
+    let error_msg = "Call JavaScript callback failed in thread safe function";
+    let mut error_msg_value = ptr::null_mut();
+    assert_eq!(
+      sys::napi_create_string_utf8(
+        raw_env,
+        error_msg.as_ptr() as *const _,
+        error_msg.len(),
+        &mut error_msg_value,
+      ),
+      sys::Status::napi_ok,
+    );
+    let mut error_value = ptr::null_mut();
+    assert_eq!(
+      sys::napi_create_error(raw_env, error_code_value, error_msg_value, &mut error_value),
+      sys::Status::napi_ok,
+    );
+    assert_eq!(
+      sys::napi_fatal_exception(raw_env, error_value),
+      sys::Status::napi_ok
+    );
+  }
 }
diff --git a/test_module/__test__/napi4/threadsafe_function.spec.ts b/test_module/__test__/napi4/threadsafe_function.spec.ts
index 9bb067a4..c158d928 100644
--- a/test_module/__test__/napi4/threadsafe_function.spec.ts
+++ b/test_module/__test__/napi4/threadsafe_function.spec.ts
@@ -1,3 +1,6 @@
+import { execSync } from 'child_process'
+import { join } from 'path'
+
 import test from 'ava'
 
 import { napiVersion } from '../napi-version'
@@ -72,3 +75,14 @@ test('should work with napi ref', (t) => {
     })
   }
 })
+
+test('should be able to throw error in tsfn', (t) => {
+  if (napiVersion < 4) {
+    t.is(bindings.testThreadsafeFunction, undefined)
+    return
+  }
+
+  t.throws(() => {
+    execSync(`node ${join(__dirname, 'tsfn-throw.js')}`)
+  })
+})
diff --git a/test_module/__test__/napi4/tsfn-throw.js b/test_module/__test__/napi4/tsfn-throw.js
new file mode 100644
index 00000000..4c630a4d
--- /dev/null
+++ b/test_module/__test__/napi4/tsfn-throw.js
@@ -0,0 +1,5 @@
+const bindings = require('../../index.node')
+
+bindings.testThreadsafeFunction(() => {
+  throw Error('Throw in thread safe function')
+})