feat: port test_typedarray SharedArrayBuffer test to CTS

Ports test/js-native-api/test_typedarray/test_sharedarraybuffer.js and its
addon from nodejs/node, covering napi_create_typedarray over a
SharedArrayBuffer-backed view.

The existing test_typedarray addon cannot host it: its CreateTypedArray
asserts napi_is_arraybuffer on the second argument, which is false for a
SharedArrayBuffer. Upstream added a separate addon for the same reason.

Gated on runtimeFeatures.typedarraySharedArrayBuffer, since the capability
only landed in Node.js v26.2.0 and v24.18.0 (nodejs/node#62710).

Fixes: #61

Signed-off-by: hexbinoct <abubakarm@gmail.com>
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: hexbinoct

implementors/node/features.js

@@ -31,4 +31,13 @@ globalThis.runtimeFeatures = {
     major > 25 ||
     (major === 25 && minor >= 4) ||
     (major === 24 && (minor > 13 || (minor === 13 && patch >= 1))),
+
+  // napi_create_typedarray accepts a SharedArrayBuffer-backed buffer only
+  // since Node.js v26.2.0 and v24.18.0 (nodejs/node#62710). The v25.x line
+  // saw no release after that landed, and it was not backported to v20.x or
+  // v22.x, where such calls fail with "invalid argument".
+  typedarraySharedArrayBuffer:
+    major > 26 ||
+    (major === 26 && minor >= 2) ||
+    (major === 24 && minor >= 18),
 };

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

@@ -1 +1,2 @@
 add_node_api_cts_addon(test_typedarray test_typedarray.c)
+add_node_api_cts_addon(test_typedarray_sharedarraybuffer test_typedarray_sharedarraybuffer.c)

tests/js-native-api/test_typedarray/test_sharedarraybuffer.js

@@ -0,0 +1,117 @@
+// napi_create_typedarray accepts a SharedArrayBuffer-backed buffer only on
+// newer Node.js releases (see implementors/node/features.js).
+if (!runtimeFeatures.typedarraySharedArrayBuffer) {
+  skipTest();
+}
+
+// Verify SharedArrayBuffer-backed typed arrays can be created through
+// napi_create_typedarray, while preserving the existing ArrayBuffer behavior.
+const addon = loadAddon('test_typedarray_sharedarraybuffer');
+
+// Float16Array is an ES2025 addition, not exposed by default in older V8
+// versions. See the longer note in test.js.
+const hasFloat16Array = typeof Float16Array !== 'undefined';
+
+const typedArrayCases = [
+  { type: Int8Array, values: [-1, 0, 127] },
+  { type: Uint8Array, values: [1, 2, 255] },
+  { type: Uint8ClampedArray, values: [0, 128, 255] },
+  { type: Int16Array, values: [-1, 0, 32767] },
+  { type: Uint16Array, values: [1, 2, 65535] },
+  { type: Int32Array, values: [-1, 0, 123456789] },
+  { type: Uint32Array, values: [1, 2, 4294967295] },
+  ...(hasFloat16Array ? [{ type: Float16Array, values: [0.5, -1.5, 42.25] }] : []),
+  { type: Float32Array, values: [0.5, -1.5, 42.25] },
+  { type: Float64Array, values: [0.5, -1.5, 42.25] },
+  { type: BigInt64Array, values: [1n, -2n, 123456789n] },
+  { type: BigUint64Array, values: [1n, 2n, 123456789n] },
+];
+
+function createBuffer(Type, BufferType, length) {
+  const byteOffset = Type.BYTES_PER_ELEMENT;
+  const byteLength = byteOffset + (length * Type.BYTES_PER_ELEMENT);
+  return {
+    buffer: new BufferType(byteLength),
+    byteOffset,
+  };
+}
+
+function verifyTypedArray(Type, buffer, byteOffset, values) {
+  const template = new Type(buffer, byteOffset, values.length);
+  const theArray = addon.CreateTypedArray(template, buffer);
+  const theArrayBuffer = addon.GetArrayBuffer(theArray);
+
+  assert.ok(theArray instanceof Type);
+  assert.strictEqual(theArray.buffer, buffer);
+  assert.strictEqual(theArrayBuffer, buffer);
+  assert.strictEqual(theArray.byteOffset, byteOffset);
+  assert.strictEqual(theArray.length, values.length);
+
+  theArray.set(values);
+  assert.deepStrictEqual(
+    Array.from(new Type(buffer, byteOffset, values.length)),
+    values,
+  );
+}
+
+// Keep the existing ArrayBuffer behavior covered while focusing this test
+// on SharedArrayBuffer-backed TypedArray creation.
+{
+  const { buffer, byteOffset } = createBuffer(Uint8Array, ArrayBuffer, 3);
+  verifyTypedArray(Uint8Array, buffer, byteOffset, [1, 2, 3]);
+}
+
+// Verify all TypedArray variants can be created from a SharedArrayBuffer.
+for (const { type, values } of typedArrayCases) {
+  const { buffer, byteOffset } = createBuffer(
+    type,
+    SharedArrayBuffer,
+    values.length,
+  );
+  verifyTypedArray(type, buffer, byteOffset, values);
+}
+
+// Test for creating TypedArrays with SharedArrayBuffer and invalid range.
+for (const { type, values } of typedArrayCases) {
+  const { buffer, byteOffset } = createBuffer(
+    type,
+    SharedArrayBuffer,
+    values.length,
+  );
+  const template = new type(buffer, byteOffset, values.length);
+
+  assert.throws(() => {
+    addon.CreateTypedArray(template, buffer, values.length + 1, byteOffset);
+  }, RangeError);
+}
+
+// Test for creating TypedArrays with SharedArrayBuffer and invalid alignment.
+for (const { type, values } of typedArrayCases) {
+  if (type.BYTES_PER_ELEMENT <= 1) {
+    continue;
+  }
+
+  const { buffer, byteOffset } = createBuffer(
+    type,
+    SharedArrayBuffer,
+    values.length,
+  );
+  const template = new type(buffer, byteOffset, values.length);
+
+  assert.throws(() => {
+    addon.CreateTypedArray(template, buffer, 1, byteOffset + 1);
+  }, RangeError);
+}
+
+// Test invalid arguments.
+{
+  const template = new Uint8Array(1);
+
+  assert.throws(() => {
+    addon.CreateTypedArray(template, {});
+  }, { name: 'Error', message: 'Invalid argument' });
+
+  assert.throws(() => {
+    addon.CreateTypedArray(template, 1);
+  }, { name: 'Error', message: 'Invalid argument' });
+}

tests/js-native-api/test_typedarray/test_typedarray_sharedarraybuffer.c

@@ -0,0 +1,79 @@
+// Verify napi_create_typedarray() accepts SharedArrayBuffer-backed views
+// without changing its existing error handling.
+
+#include <js_native_api.h>
+#include "../common.h"
+#include "../entry_point.h"
+
+static napi_value CreateTypedArray(napi_env env, napi_callback_info info) {
+  size_t argc = 4;
+  napi_value args[4];
+  NODE_API_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  NODE_API_ASSERT(env, argc == 2 || argc == 4, "Wrong number of arguments");
+
+  bool is_typedarray;
+  NODE_API_CALL(env, napi_is_typedarray(env, args[0], &is_typedarray));
+  NODE_API_ASSERT(env,
+                  is_typedarray,
+                  "Wrong type of arguments. Expects a typed array as first "
+                  "argument.");
+
+  napi_typedarray_type type;
+  size_t length;
+  size_t byte_offset;
+  NODE_API_CALL(env,
+                napi_get_typedarray_info(
+                    env, args[0], &type, &length, NULL, NULL, &byte_offset));
+
+  if (argc == 4) {
+    uint32_t uint32_length;
+    NODE_API_CALL(env, napi_get_value_uint32(env, args[2], &uint32_length));
+    length = uint32_length;
+
+    uint32_t uint32_byte_offset;
+    NODE_API_CALL(env,
+                  napi_get_value_uint32(env, args[3], &uint32_byte_offset));
+    byte_offset = uint32_byte_offset;
+  }
+
+  napi_value typedarray;
+  NODE_API_CALL(env,
+                napi_create_typedarray(
+                    env, type, length, args[1], byte_offset, &typedarray));
+
+  return typedarray;
+}
+
+static napi_value GetArrayBuffer(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));
+
+  NODE_API_ASSERT(env, argc == 1, "Wrong number of arguments");
+
+  napi_value arraybuffer;
+  NODE_API_CALL(env,
+                napi_get_typedarray_info(
+                    env, args[0], NULL, NULL, NULL, &arraybuffer, NULL));
+
+  return arraybuffer;
+}
+
+EXTERN_C_START
+napi_value Init(napi_env env, napi_value exports) {
+  napi_property_descriptor descriptors[] = {
+      DECLARE_NODE_API_PROPERTY("CreateTypedArray", CreateTypedArray),
+      DECLARE_NODE_API_PROPERTY("GetArrayBuffer", GetArrayBuffer),
+  };
+
+  NODE_API_CALL(
+      env,
+      napi_define_properties(env,
+                             exports,
+                             sizeof(descriptors) / sizeof(*descriptors),
+                             descriptors));
+
+  return exports;
+}
+EXTERN_C_END