test: port worker + buffer test to N-API

This ports `test/addons/worker-buffer-callback` to N-API,
with the small exception of using external `ArrayBuffer`s rather
than external Node.js `Buffer`s.

PR-URL: #30551
Reviewed-By: Gabriel Schulhof <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Denys Otrishko <[email protected]>
Reviewed-By: Michael Dawson <[email protected]>

Author: addaleax

test/node-api/test_worker_buffer_callback/binding.gyp

@@ -0,0 +1,8 @@
+{
+  'targets': [
+    {
+      'target_name': 'binding',
+      'sources': [ 'test_worker_buffer_callback.c' ]
+    }
+  ]
+}

test/node-api/test_worker_buffer_callback/test-free-called.js

@@ -0,0 +1,17 @@
+'use strict';
+const common = require('../../common');
+const path = require('path');
+const assert = require('assert');
+const { Worker } = require('worker_threads');
+const binding = path.resolve(__dirname, `./build/${common.buildType}/binding`);
+const { getFreeCallCount } = require(binding);
+
+// Test that buffers allocated with a free callback through our APIs are
+// released when a Worker owning it exits.
+
+const w = new Worker(`require(${JSON.stringify(binding)})`, { eval: true });
+
+assert.strictEqual(getFreeCallCount(), 0);
+w.on('exit', common.mustCall(() => {
+  assert.strictEqual(getFreeCallCount(), 1);
+}));

test/node-api/test_worker_buffer_callback/test.js

@@ -0,0 +1,15 @@
+'use strict';
+const common = require('../../common');
+const assert = require('assert');
+const { MessageChannel } = require('worker_threads');
+const { buffer } = require(`./build/${common.buildType}/binding`);
+
+// Test that buffers allocated with a free callback through our APIs are not
+// transferred.
+
+const { port1 } = new MessageChannel();
+const origByteLength = buffer.byteLength;
+port1.postMessage(buffer, [buffer]);
+
+assert.strictEqual(buffer.byteLength, origByteLength);
+assert.notStrictEqual(buffer.byteLength, 0);

test/node-api/test_worker_buffer_callback/test_worker_buffer_callback.c

@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include <node_api.h>
+#include <assert.h>
+#include "../../js-native-api/common.h"
+
+uint32_t free_call_count = 0;
+char data[] = "hello";
+
+napi_value GetFreeCallCount(napi_env env, napi_callback_info info) {
+  napi_value value;
+  NAPI_CALL(env, napi_create_uint32(env, free_call_count, &value));
+  return value;
+}
+
+static void finalize_cb(napi_env env, void* finalize_data, void* hint) {
+  assert(finalize_data == data);
+  free_call_count++;
+}
+
+NAPI_MODULE_INIT() {
+  napi_property_descriptor properties[] = {
+    DECLARE_NAPI_PROPERTY("getFreeCallCount", GetFreeCallCount)
+  };
+
+  NAPI_CALL(env, napi_define_properties(
+      env, exports, sizeof(properties) / sizeof(*properties), properties));
+
+  // This is a slight variation on the non-N-API test: We create an ArrayBuffer
+  // rather than a Node.js Buffer, since testing the latter would only test
+  // the same code paths and not the ones specific to N-API.
+  napi_value buffer;
+  NAPI_CALL(env, napi_create_external_arraybuffer(
+      env,
+      data,
+      sizeof(data),
+      finalize_cb,
+      NULL,
+      &buffer));
+
+  NAPI_CALL(env, napi_set_named_property(env, exports, "buffer", buffer));
+
+  return exports;
+}