napi: add test for exception handling implementation

test/addons-abi/test_exception/binding.gyp

@@ -0,0 +1,8 @@
+{
+  "targets": [
+    {
+      "target_name": "test_exception",
+      "sources": [ "test_exception.cc" ]
+    }
+  ]
+}

test/addons-abi/test_exception/test.js

@@ -0,0 +1,48 @@
+'use strict';
+
+var test_exception = require( "./build/Release/test_exception" );
+var assert = require( "assert" );
+var theError = new Error( "Some error" );
+var throwTheError = function() {
+	throw theError;
+};
+var caughtError;
+
+var throwNoError = function() {};
+
+// Test that the native side successfully captures the exception
+var returnedError = test_exception.returnException( throwTheError );
+assert.strictEqual( theError, returnedError,
+	"Returned error is strictly equal to the thrown error" );
+
+// Test that the native side passes the exception through
+try {
+	test_exception.allowException( throwTheError );
+} catch ( anError ) {
+	caughtError = anError;
+}
+assert.strictEqual( caughtError, theError,
+	"Thrown exception was allowed to pass through unhindered" );
+caughtError = undefined;
+
+// Test that the exception thrown above was marked as pending before it was handled on the JS side
+assert.strictEqual( test_exception.wasPending(), true,
+	"VM was marked as having an exception pending when it was allowed through" );
+
+// Test that the native side does not capture a non-existing exception
+returnedError = test_exception.returnException( throwNoError );
+assert.strictEqual( undefined, returnedError,
+	"Returned error is undefined when no exception is thrown" );
+
+// Test that no exception appears that was not thrown by us
+try {
+	test_exception.allowException( throwNoError );
+} catch( anError ) {
+	caughtError = anError;
+}
+assert.strictEqual( undefined, caughtError,
+	"No exception originated on the native side" );
+
+// Test that the exception state remains clear when no exception is thrown
+assert.strictEqual( test_exception.wasPending(), false,
+	"VM was not marked as having an exception pending when none was allowed through" );

test/addons-abi/test_exception/test_exception.cc

@@ -0,0 +1,44 @@
+#include <node_jsvmapi.h>
+#include <node_api_helpers.h>
+
+static bool exceptionWasPending = false;
+
+NAPI_METHOD(returnException) {
+  napi_value jsFunction;
+
+  napi_get_cb_args(env, info, &jsFunction, 1);
+
+  // What is the return value when there was an exception?
+  napi_call_function(env, napi_get_global_scope(env), jsFunction, 0, 0);
+
+  napi_set_return_value(env, info, napi_get_and_clear_last_exception(env));
+}
+
+NAPI_METHOD(allowException) {
+  napi_value jsFunction;
+
+  napi_get_cb_args(env, info, &jsFunction, 1);
+
+  napi_call_function(env, napi_get_global_scope(env), jsFunction, 0, 0);
+
+  exceptionWasPending = napi_is_exception_pending(env);
+}
+
+NAPI_METHOD(wasPending) {
+  napi_set_return_value(env, info,
+    napi_create_boolean(env, exceptionWasPending));
+}
+
+NAPI_MODULE_INIT(Init) {
+  napi_set_property(env, exports,
+                    napi_property_name(env, "returnException"),
+                    napi_create_function(env, returnException));
+  napi_set_property(env, exports,
+                    napi_property_name(env, "allowException"),
+                    napi_create_function(env, allowException));
+  napi_set_property(env, exports,
+                    napi_property_name(env, "wasPending"),
+                    napi_create_function(env, wasPending));
+}
+
+NODE_MODULE_ABI(addon, Init)