nodejs · bavulapati · Apr 1, 2026
diff --git a/PORTING.md b/PORTING.md
@@ -69,7 +69,7 @@ Tests covering the engine-specific part of Node-API, defined in `js_native_api.h
 | `test_reference`             | Not ported | Medium     |
 | `test_reference_double_free` | Ported ✅  | Easy       |
 | `test_sharedarraybuffer`     | Not ported | Medium     |
-| `test_string`                | Not ported | Medium     |
+| `test_string`                | Ported ✅  | Medium     |
 | `test_symbol`                | Ported ✅  | Easy       |
 | `test_typedarray`            | Not ported | Medium     |
 

diff --git a/tests/js-native-api/test_string/CMakeLists.txt b/tests/js-native-api/test_string/CMakeLists.txt
@@ -0,0 +1,3 @@
+add_node_api_cts_addon(test_string test_string.c test_null.c)
+# API like node_api_create_external_string_latin1 are available from NAPI_VERSION >= 10
+target_compile_definitions(test_string PRIVATE NAPI_VERSION=10)
diff --git a/tests/js-native-api/test_string/test.js b/tests/js-native-api/test_string/test.js
@@ -0,0 +1,104 @@
+"use strict";
+
+// Testing api calls for string
+const test_string = loadAddon("test_string");
+// The insufficient buffer test case allocates a buffer of size 4, including
+// the null terminator.
+const kInsufficientIdx = 3;
+
+const asciiCases = [
+  "",
+  "hello world",
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
+  "?!@#$%^&*()_+-=[]{}/.,<>'\"\\",
+];
+
+const latin1Cases = [
+  {
+    str: "¡¢£¤¥¦§¨©ª«¬®¯°±²³´µ¶·¸¹º»¼½¾¿",
+    utf8Length: 62,
+    utf8InsufficientIdx: 1,
+  },
+  {
+    str: "ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþ",
+    utf8Length: 126,
+    utf8InsufficientIdx: 1,
+  },
+];
+
+const unicodeCases = [
+  {
+    str: "\u{2003}\u{2101}\u{2001}\u{202}\u{2011}",
+    utf8Length: 14,
+    utf8InsufficientIdx: 1,
+  },
+];
+
+function testLatin1Cases(str) {
+  assert.strictEqual(test_string.TestLatin1(str), str);
+  assert.strictEqual(test_string.TestLatin1AutoLength(str), str);
+  assert.strictEqual(test_string.TestLatin1External(str), str);
+  assert.strictEqual(test_string.TestLatin1ExternalAutoLength(str), str);
+  assert.strictEqual(test_string.TestPropertyKeyLatin1(str), str);
+  assert.strictEqual(test_string.TestPropertyKeyLatin1AutoLength(str), str);
+  assert.strictEqual(test_string.Latin1Length(str), str.length);
+
+  if (str !== "") {
+    assert.strictEqual(
+      test_string.TestLatin1Insufficient(str),
+      str.slice(0, kInsufficientIdx),
+    );
+  }
+}
+
+function testUnicodeCases(str, utf8Length, utf8InsufficientIdx) {
+  assert.strictEqual(test_string.TestUtf8(str), str);
+  assert.strictEqual(test_string.TestUtf16(str), str);
+  assert.strictEqual(test_string.TestUtf8AutoLength(str), str);
+  assert.strictEqual(test_string.TestUtf16AutoLength(str), str);
+  assert.strictEqual(test_string.TestUtf16External(str), str);
+  assert.strictEqual(test_string.TestUtf16ExternalAutoLength(str), str);
+  assert.strictEqual(test_string.TestPropertyKeyUtf8(str), str);
+  assert.strictEqual(test_string.TestPropertyKeyUtf8AutoLength(str), str);
+  assert.strictEqual(test_string.TestPropertyKeyUtf16(str), str);
+  assert.strictEqual(test_string.TestPropertyKeyUtf16AutoLength(str), str);
+  assert.strictEqual(test_string.Utf8Length(str), utf8Length);
+  assert.strictEqual(test_string.Utf16Length(str), str.length);
+
+  if (str !== "") {
+    assert.strictEqual(
+      test_string.TestUtf8Insufficient(str),
+      str.slice(0, utf8InsufficientIdx),
+    );
+    assert.strictEqual(
+      test_string.TestUtf16Insufficient(str),
+      str.slice(0, kInsufficientIdx),
+    );
+  }
+}
+
+asciiCases.forEach(testLatin1Cases);
+asciiCases.forEach((str) =>
+  testUnicodeCases(str, str.length, kInsufficientIdx),
+);
+latin1Cases.forEach((it) => testLatin1Cases(it.str));
+latin1Cases.forEach((it) =>
+  testUnicodeCases(it.str, it.utf8Length, it.utf8InsufficientIdx),
+);
+unicodeCases.forEach((it) =>
+  testUnicodeCases(it.str, it.utf8Length, it.utf8InsufficientIdx),
+);
+
+assert.throws(() => {
+  test_string.TestLargeUtf8();
+}, /^Error: Invalid argument$/);
+
+assert.throws(() => {
+  test_string.TestLargeLatin1();
+}, /^Error: Invalid argument$/);
+
+assert.throws(() => {
+  test_string.TestLargeUtf16();
+}, /^Error: Invalid argument$/);
+
+test_string.TestMemoryCorruption(" ".repeat(64 * 1024));
diff --git a/tests/js-native-api/test_string/test_null.c b/tests/js-native-api/test_string/test_null.c
@@ -0,0 +1,71 @@
+#include <js_native_api.h>
+
+#include "../common.h"
+#include "test_null.h"
+
+#define DECLARE_TEST(charset, str_arg)                                    \
+  static napi_value                                                       \
+  test_create_##charset(napi_env env, napi_callback_info info) {          \
+    napi_value return_value, result;                                      \
+    NODE_API_CALL(env, napi_create_object(env, &return_value));           \
+                                                                          \
+    add_returned_status(env,                                              \
+                        "envIsNull",                                      \
+                        return_value,                                     \
+                        "Invalid argument",                               \
+                        napi_invalid_arg,                                 \
+                        napi_create_string_##charset(NULL,                \
+                                                     (str_arg),           \
+                                                     NAPI_AUTO_LENGTH,    \
+                                                     &result));           \
+                                                                          \
+    napi_create_string_##charset(env, NULL, NAPI_AUTO_LENGTH, &result);   \
+    add_last_status(env, "stringIsNullNonZeroLength", return_value);      \
+                                                                          \
+    napi_create_string_##charset(env, NULL, 0, &result);                  \
+    add_last_status(env, "stringIsNullZeroLength", return_value);         \
+                                                                          \
+    napi_create_string_##charset(env, (str_arg), NAPI_AUTO_LENGTH, NULL); \
+    add_last_status(env, "resultIsNull", return_value);                   \
+                                                                          \
+    return return_value;                                                  \
+  }
+
+static const char16_t something[] = {
+  (char16_t)'s',
+  (char16_t)'o',
+  (char16_t)'m',
+  (char16_t)'e',
+  (char16_t)'t',
+  (char16_t)'h',
+  (char16_t)'i',
+  (char16_t)'n',
+  (char16_t)'g',
+  (char16_t)'\0'
+};
+
+DECLARE_TEST(utf8, "something")
+DECLARE_TEST(latin1, "something")
+DECLARE_TEST(utf16, something)
+
+void init_test_null(napi_env env, napi_value exports) {
+  napi_value test_null;
+
+  const napi_property_descriptor test_null_props[] = {
+    DECLARE_NODE_API_PROPERTY("test_create_utf8", test_create_utf8),
+    DECLARE_NODE_API_PROPERTY("test_create_latin1", test_create_latin1),
+    DECLARE_NODE_API_PROPERTY("test_create_utf16", test_create_utf16),
+  };
+
+  NODE_API_CALL_RETURN_VOID(env, napi_create_object(env, &test_null));
+  NODE_API_CALL_RETURN_VOID(env, napi_define_properties(
+      env, test_null, sizeof(test_null_props) / sizeof(*test_null_props),
+      test_null_props));
+
+  const napi_property_descriptor test_null_set = {
+    "testNull", NULL, NULL, NULL, NULL, test_null, napi_enumerable, NULL
+  };
+
+  NODE_API_CALL_RETURN_VOID(env,
+      napi_define_properties(env, exports, 1, &test_null_set));
+}
diff --git a/tests/js-native-api/test_string/test_null.h b/tests/js-native-api/test_string/test_null.h
@@ -0,0 +1,8 @@
+#ifndef TEST_JS_NATIVE_API_TEST_STRING_TEST_NULL_H_
+#define TEST_JS_NATIVE_API_TEST_STRING_TEST_NULL_H_
+
+#include <js_native_api.h>
+
+void init_test_null(napi_env env, napi_value exports);
+
+#endif  // TEST_JS_NATIVE_API_TEST_STRING_TEST_NULL_H_
diff --git a/tests/js-native-api/test_string/test_null.js b/tests/js-native-api/test_string/test_null.js
@@ -0,0 +1,15 @@
+"use strict";
+
+// Test passing NULL to object-related Node-APIs.
+const { testNull } = loadAddon("test_string");
+
+const expectedResult = {
+  envIsNull: "Invalid argument",
+  stringIsNullNonZeroLength: "Invalid argument",
+  stringIsNullZeroLength: "napi_ok",
+  resultIsNull: "Invalid argument",
+};
+
+assert.deepStrictEqual(expectedResult, testNull.test_create_latin1());
+assert.deepStrictEqual(expectedResult, testNull.test_create_utf8());
+assert.deepStrictEqual(expectedResult, testNull.test_create_utf16());