feat: port test_exception to CTS

PORTING.md

@@ -55,7 +55,7 @@ Tests covering the engine-specific part of Node-API, defined in `js_native_api.h
 | `test_dataview`              | Ported ✅  | Medium     |
 | `test_date`                  | Ported ✅  | Easy       |
 | `test_error`                 | Ported ✅  | Medium     |
-| `test_exception`             | Not ported | Medium     |
+| `test_exception`             | Ported ✅  | Medium     |
 | `test_finalizer`             | Not ported | Medium     |
 | `test_function`              | Ported ✅  | Medium     |
 | `test_general`               | Not ported | Hard       |

tests/js-native-api/test_exception/CMakeLists.txt

@@ -0,0 +1 @@
+add_node_api_cts_addon(test_exception test_exception.c)

tests/js-native-api/test_exception/test.js

@@ -0,0 +1,145 @@
+'use strict';
+
+const theError = new Error('Some error');
+
+// The test module throws an error during Init, but in order for its exports to
+// not be lost, it attaches them to the error's "bindings" property. This way,
+// we can make sure that exceptions thrown during the module initialization
+// phase are propagated through require() into JavaScript.
+// https://github.com/nodejs/node/issues/19437
+const test_exception = (function() {
+  let resultingException;
+  try {
+    loadAddon('test_exception');
+  } catch (anException) {
+    resultingException = anException;
+  }
+  assert.strictEqual(resultingException.message, 'Error during Init');
+  return resultingException.binding;
+})();
+
+{
+  const throwTheError = () => {
+    throw theError;
+  };
+
+  // Test that the native side successfully captures the exception
+  let returnedError = test_exception.returnException(throwTheError);
+  assert.strictEqual(returnedError, theError);
+
+  // Test that the native side passes the exception through
+  assert.throws(
+    () => {
+      test_exception.allowException(throwTheError);
+    },
+    (err) => err === theError,
+  );
+
+  // Test that the exception thrown above was marked as pending
+  // before it was handled on the JS side
+  const exception_pending = test_exception.wasPending();
+  assert.strictEqual(
+    exception_pending,
+    true,
+    'Exception not pending as expected,' +
+      ` .wasPending() returned ${exception_pending}`,
+  );
+
+  // Test that the native side does not capture a non-existing exception
+  returnedError = test_exception.returnException(mustCall());
+  assert.strictEqual(
+    returnedError,
+    undefined,
+    'Returned error should be undefined when no exception is' +
+      ` thrown, but ${returnedError} was passed`,
+  );
+}
+
+{
+  const throwTheError = class {
+    constructor() {
+      throw theError;
+    }
+  };
+
+  // Test that the native side successfully captures the exception
+  let returnedError = test_exception.constructReturnException(throwTheError);
+  assert.strictEqual(returnedError, theError);
+
+  // Test that the native side passes the exception through
+  assert.throws(
+    () => {
+      test_exception.constructAllowException(throwTheError);
+    },
+    (err) => err === theError,
+  );
+
+  // Test that the exception thrown above was marked as pending
+  // before it was handled on the JS side
+  const exception_pending = test_exception.wasPending();
+  assert.strictEqual(
+    exception_pending,
+    true,
+    'Exception not pending as expected,' +
+      ` .wasPending() returned ${exception_pending}`,
+  );
+
+  // Test that the native side does not capture a non-existing exception
+  returnedError = test_exception.constructReturnException(mustCall());
+  assert.strictEqual(
+    returnedError,
+    undefined,
+    'Returned error should be undefined when no exception is' +
+      ` thrown, but ${returnedError} was passed`,
+  );
+}
+
+{
+  // Test that no exception appears that was not thrown by us
+  let caughtError;
+  try {
+    test_exception.allowException(mustCall());
+  } catch (anError) {
+    caughtError = anError;
+  }
+  assert.strictEqual(
+    caughtError,
+    undefined,
+    'No exception originated on the native side, but' +
+      ` ${caughtError} was passed`,
+  );
+
+  // Test that the exception state remains clear when no exception is thrown
+  const exception_pending = test_exception.wasPending();
+  assert.strictEqual(
+    exception_pending,
+    false,
+    'Exception state did not remain clear as expected,' +
+      ` .wasPending() returned ${exception_pending}`,
+  );
+}
+
+{
+  // Test that no exception appears that was not thrown by us
+  let caughtError;
+  try {
+    test_exception.constructAllowException(mustCall());
+  } catch (anError) {
+    caughtError = anError;
+  }
+  assert.strictEqual(
+    caughtError,
+    undefined,
+    'No exception originated on the native side, but' +
+      ` ${caughtError} was passed`,
+  );
+
+  // Test that the exception state remains clear when no exception is thrown
+  const exception_pending = test_exception.wasPending();
+  assert.strictEqual(
+    exception_pending,
+    false,
+    'Exception state did not remain clear as expected,' +
+      ` .wasPending() returned ${exception_pending}`,
+  );
+}

tests/js-native-api/test_exception/testFinalizerException.js

@@ -0,0 +1,26 @@
+// A C finalizer that throws during GC surfaces as an uncaught exception. This
+// mirrors test_reference/test_finalizer.js, except the addon here throws from
+// Init; its exports are still reachable via the error's `.binding`, so a
+// finalizer can be installed even though initialization failed.
+const binding = (function() {
+  let resultingException;
+  try {
+    loadAddon('test_exception');
+  } catch (anException) {
+    resultingException = anException;
+  }
+  assert.strictEqual(resultingException.message, 'Error during Init');
+  return resultingException.binding;
+})();
+
+onUncaughtException(mustCall((err) => {
+  assert.match(err.message, /Error during Finalize/);
+}));
+
+(async function() {
+  binding.createExternal();
+
+  // GC until the finalizer fires; the counter just bounds the loop.
+  let gcCount = 10;
+  await gcUntil('test', () => --gcCount <= 0);
+})().then(mustCall());

tests/js-native-api/test_exception/test_exception.c

@@ -0,0 +1,116 @@
+#include <js_native_api.h>
+#include "../common.h"
+#include "../entry_point.h"
+
+static bool exceptionWasPending = false;
+static int num = 0x23432;
+
+static napi_value returnException(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  napi_value global;
+  NODE_API_CALL(env, napi_get_global(env, &global));
+
+  napi_value result;
+  napi_status status = napi_call_function(env, global, args[0], 0, 0, &result);
+  if (status == napi_pending_exception) {
+    napi_value ex;
+    NODE_API_CALL(env, napi_get_and_clear_last_exception(env, &ex));
+    return ex;
+  }
+
+  return NULL;
+}
+
+static napi_value constructReturnException(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  napi_value result;
+  napi_status status = napi_new_instance(env, args[0], 0, 0, &result);
+  if (status == napi_pending_exception) {
+    napi_value ex;
+    NODE_API_CALL(env, napi_get_and_clear_last_exception(env, &ex));
+    return ex;
+  }
+
+  return NULL;
+}
+
+static napi_value allowException(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  napi_value global;
+  NODE_API_CALL(env, napi_get_global(env, &global));
+
+  napi_value result;
+  napi_call_function(env, global, args[0], 0, 0, &result);
+  // Ignore status and check napi_is_exception_pending() instead.
+
+  NODE_API_CALL(env, napi_is_exception_pending(env, &exceptionWasPending));
+  return NULL;
+}
+
+static napi_value constructAllowException(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  napi_value result;
+  napi_new_instance(env, args[0], 0, 0, &result);
+  // Ignore status and check napi_is_exception_pending() instead.
+
+  NODE_API_CALL(env, napi_is_exception_pending(env, &exceptionWasPending));
+  return NULL;
+}
+
+static napi_value wasPending(napi_env env, napi_callback_info info) {
+  napi_value result;
+  NODE_API_CALL(env, napi_get_boolean(env, exceptionWasPending, &result));
+
+  return result;
+}
+
+static void finalizer(napi_env env, void *data, void *hint) {
+  NODE_API_CALL_RETURN_VOID(env,
+      napi_throw_error(env, NULL, "Error during Finalize"));
+}
+
+static napi_value createExternal(napi_env env, napi_callback_info info) {
+  napi_value external;
+
+  NODE_API_CALL(env,
+      napi_create_external(env, &num, finalizer, NULL, &external));
+
+  return external;
+}
+
+EXTERN_C_START
+napi_value Init(napi_env env, napi_value exports) {
+  napi_property_descriptor descriptors[] = {
+    DECLARE_NODE_API_PROPERTY("returnException", returnException),
+    DECLARE_NODE_API_PROPERTY("allowException", allowException),
+    DECLARE_NODE_API_PROPERTY("constructReturnException", constructReturnException),
+    DECLARE_NODE_API_PROPERTY("constructAllowException", constructAllowException),
+    DECLARE_NODE_API_PROPERTY("wasPending", wasPending),
+    DECLARE_NODE_API_PROPERTY("createExternal", createExternal),
+  };
+  NODE_API_CALL(env, napi_define_properties(
+      env, exports, sizeof(descriptors) / sizeof(*descriptors), descriptors));
+
+  napi_value error, code, message;
+  NODE_API_CALL(env, napi_create_string_utf8(env, "Error during Init",
+      NAPI_AUTO_LENGTH, &message));
+  NODE_API_CALL(env, napi_create_string_utf8(env, "", NAPI_AUTO_LENGTH, &code));
+  NODE_API_CALL(env, napi_create_error(env, code, message, &error));
+  NODE_API_CALL(env, napi_set_named_property(env, error, "binding", exports));
+  NODE_API_CALL(env, napi_throw(env, error));
+
+  return exports;
+}
+EXTERN_C_END