diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4cca97b..c0fd55e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,8 @@
 ## v1.5.1-dev
 
 * No longer test the `setup-dart` action on pre-2.12 SDKs.
-* Upgrade JS interop code to use inline classes.
+* Upgrade JS interop code to use extension types
+  (the new name for inline classes).
 
 ## v1.5.0
 
diff --git a/dist/index.mjs b/dist/index.mjs
index 00dd09b..a4a4b8d 100644
--- a/dist/index.mjs
+++ b/dist/index.mjs
@@ -1,7 +1,7 @@
 import { createRequire as __WEBPACK_EXTERNAL_createRequire } from "module";
 /******/ var __webpack_modules__ = ({
 
-/***/ 2690:
+/***/ 5604:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -27,7 +27,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.issue = exports.issueCommand = void 0;
 const os = __importStar(__nccwpck_require__(2037));
-const utils_1 = __nccwpck_require__(353);
+const utils_1 = __nccwpck_require__(1245);
 /**
  * Commands
  *
@@ -99,7 +99,7 @@ function escapeProperty(s) {
 
 /***/ }),
 
-/***/ 9935:
+/***/ 5127:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -133,12 +133,12 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.getIDToken = exports.getState = exports.saveState = exports.group = exports.endGroup = exports.startGroup = exports.info = exports.notice = exports.warning = exports.error = exports.debug = exports.isDebug = exports.setFailed = exports.setCommandEcho = exports.setOutput = exports.getBooleanInput = exports.getMultilineInput = exports.getInput = exports.addPath = exports.setSecret = exports.exportVariable = exports.ExitCode = void 0;
-const command_1 = __nccwpck_require__(2690);
-const file_command_1 = __nccwpck_require__(5898);
-const utils_1 = __nccwpck_require__(353);
+const command_1 = __nccwpck_require__(5604);
+const file_command_1 = __nccwpck_require__(7352);
+const utils_1 = __nccwpck_require__(1245);
 const os = __importStar(__nccwpck_require__(2037));
 const path = __importStar(__nccwpck_require__(1017));
-const oidc_utils_1 = __nccwpck_require__(7901);
+const oidc_utils_1 = __nccwpck_require__(4457);
 /**
  * The code to exit an action
  */
@@ -423,17 +423,17 @@ exports.getIDToken = getIDToken;
 /**
  * Summary exports
  */
-var summary_1 = __nccwpck_require__(9050);
+var summary_1 = __nccwpck_require__(9124);
 Object.defineProperty(exports, "summary", ({ enumerable: true, get: function () { return summary_1.summary; } }));
 /**
  * @deprecated use core.summary
  */
-var summary_2 = __nccwpck_require__(9050);
+var summary_2 = __nccwpck_require__(9124);
 Object.defineProperty(exports, "markdownSummary", ({ enumerable: true, get: function () { return summary_2.markdownSummary; } }));
 /**
  * Path exports
  */
-var path_utils_1 = __nccwpck_require__(1341);
+var path_utils_1 = __nccwpck_require__(7169);
 Object.defineProperty(exports, "toPosixPath", ({ enumerable: true, get: function () { return path_utils_1.toPosixPath; } }));
 Object.defineProperty(exports, "toWin32Path", ({ enumerable: true, get: function () { return path_utils_1.toWin32Path; } }));
 Object.defineProperty(exports, "toPlatformPath", ({ enumerable: true, get: function () { return path_utils_1.toPlatformPath; } }));
@@ -441,7 +441,7 @@ Object.defineProperty(exports, "toPlatformPath", ({ enumerable: true, get: funct
 
 /***/ }),
 
-/***/ 5898:
+/***/ 7352:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -471,8 +471,8 @@ exports.prepareKeyValueMessage = exports.issueFileCommand = void 0;
 /* eslint-disable @typescript-eslint/no-explicit-any */
 const fs = __importStar(__nccwpck_require__(7147));
 const os = __importStar(__nccwpck_require__(2037));
-const uuid_1 = __nccwpck_require__(1368);
-const utils_1 = __nccwpck_require__(353);
+const uuid_1 = __nccwpck_require__(9267);
+const utils_1 = __nccwpck_require__(1245);
 function issueFileCommand(command, message) {
     const filePath = process.env[`GITHUB_${command}`];
     if (!filePath) {
@@ -505,7 +505,7 @@ exports.prepareKeyValueMessage = prepareKeyValueMessage;
 
 /***/ }),
 
-/***/ 7901:
+/***/ 4457:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -520,9 +520,9 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.OidcClient = void 0;
-const http_client_1 = __nccwpck_require__(3658);
-const auth_1 = __nccwpck_require__(2660);
-const core_1 = __nccwpck_require__(9935);
+const http_client_1 = __nccwpck_require__(6227);
+const auth_1 = __nccwpck_require__(5181);
+const core_1 = __nccwpck_require__(5127);
 class OidcClient {
     static createHttpClient(allowRetry = true, maxRetry = 10) {
         const requestOptions = {
@@ -588,7 +588,7 @@ exports.OidcClient = OidcClient;
 
 /***/ }),
 
-/***/ 1341:
+/***/ 7169:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -652,7 +652,7 @@ exports.toPlatformPath = toPlatformPath;
 
 /***/ }),
 
-/***/ 9050:
+/***/ 9124:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -941,7 +941,7 @@ exports.summary = _summary;
 
 /***/ }),
 
-/***/ 353:
+/***/ 1245:
 /***/ ((__unused_webpack_module, exports) => {
 
 
@@ -987,7 +987,7 @@ exports.toCommandProperties = toCommandProperties;
 
 /***/ }),
 
-/***/ 3409:
+/***/ 2049:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -1022,7 +1022,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.getExecOutput = exports.exec = void 0;
 const string_decoder_1 = __nccwpck_require__(1576);
-const tr = __importStar(__nccwpck_require__(1139));
+const tr = __importStar(__nccwpck_require__(1469));
 /**
  * Exec a command.
  * Output will be streamed to the live console.
@@ -1096,7 +1096,7 @@ exports.getExecOutput = getExecOutput;
 
 /***/ }),
 
-/***/ 1139:
+/***/ 1469:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -1134,8 +1134,8 @@ const os = __importStar(__nccwpck_require__(2037));
 const events = __importStar(__nccwpck_require__(2361));
 const child = __importStar(__nccwpck_require__(2081));
 const path = __importStar(__nccwpck_require__(1017));
-const io = __importStar(__nccwpck_require__(2725));
-const ioUtil = __importStar(__nccwpck_require__(573));
+const io = __importStar(__nccwpck_require__(2864));
+const ioUtil = __importStar(__nccwpck_require__(1887));
 const timers_1 = __nccwpck_require__(9512);
 /* eslint-disable @typescript-eslint/unbound-method */
 const IS_WINDOWS = process.platform === 'win32';
@@ -1720,7 +1720,7 @@ class ExecState extends events.EventEmitter {
 
 /***/ }),
 
-/***/ 2660:
+/***/ 5181:
 /***/ (function(__unused_webpack_module, exports) {
 
 
@@ -1807,7 +1807,7 @@ exports.PersonalAccessTokenCredentialHandler = PersonalAccessTokenCredentialHand
 
 /***/ }),
 
-/***/ 3658:
+/***/ 6227:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -1844,8 +1844,8 @@ Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.HttpClient = exports.isHttps = exports.HttpClientResponse = exports.HttpClientError = exports.getProxyUrl = exports.MediaTypes = exports.Headers = exports.HttpCodes = void 0;
 const http = __importStar(__nccwpck_require__(3685));
 const https = __importStar(__nccwpck_require__(5687));
-const pm = __importStar(__nccwpck_require__(9697));
-const tunnel = __importStar(__nccwpck_require__(7477));
+const pm = __importStar(__nccwpck_require__(603));
+const tunnel = __importStar(__nccwpck_require__(7265));
 var HttpCodes;
 (function (HttpCodes) {
     HttpCodes[HttpCodes["OK"] = 200] = "OK";
@@ -2418,7 +2418,7 @@ const lowercaseKeys = (obj) => Object.keys(obj).reduce((c, k) => ((c[k.toLowerCa
 
 /***/ }),
 
-/***/ 9697:
+/***/ 603:
 /***/ ((__unused_webpack_module, exports) => {
 
 
@@ -2485,7 +2485,7 @@ exports.checkBypass = checkBypass;
 
 /***/ }),
 
-/***/ 573:
+/***/ 1887:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -2668,7 +2668,7 @@ exports.getCmdPath = getCmdPath;
 
 /***/ }),
 
-/***/ 2725:
+/***/ 2864:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -2706,7 +2706,7 @@ const assert_1 = __nccwpck_require__(9491);
 const childProcess = __importStar(__nccwpck_require__(2081));
 const path = __importStar(__nccwpck_require__(1017));
 const util_1 = __nccwpck_require__(3837);
-const ioUtil = __importStar(__nccwpck_require__(573));
+const ioUtil = __importStar(__nccwpck_require__(1887));
 const exec = util_1.promisify(childProcess.exec);
 const execFile = util_1.promisify(childProcess.execFile);
 /**
@@ -3015,7 +3015,7 @@ function copyFile(srcFile, destFile, force) {
 
 /***/ }),
 
-/***/ 7936:
+/***/ 9024:
 /***/ (function(module, exports, __nccwpck_require__) {
 
 
@@ -3049,8 +3049,8 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports._readLinuxVersionFile = exports._getOsVersion = exports._findMatch = void 0;
-const semver = __importStar(__nccwpck_require__(7163));
-const core_1 = __nccwpck_require__(9935);
+const semver = __importStar(__nccwpck_require__(1156));
+const core_1 = __nccwpck_require__(5127);
 // needs to be require for core node modules to be mocked
 /* eslint @typescript-eslint/no-require-imports: 0 */
 const os = __nccwpck_require__(2037);
@@ -3149,7 +3149,7 @@ exports._readLinuxVersionFile = _readLinuxVersionFile;
 
 /***/ }),
 
-/***/ 721:
+/***/ 6429:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -3183,7 +3183,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.RetryHelper = void 0;
-const core = __importStar(__nccwpck_require__(9935));
+const core = __importStar(__nccwpck_require__(5127));
 /**
  * Internal class for retries
  */
@@ -3238,7 +3238,7 @@ exports.RetryHelper = RetryHelper;
 
 /***/ }),
 
-/***/ 2275:
+/***/ 9348:
 /***/ (function(__unused_webpack_module, exports, __nccwpck_require__) {
 
 
@@ -3275,20 +3275,20 @@ var __importDefault = (this && this.__importDefault) || function (mod) {
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.evaluateVersions = exports.isExplicitVersion = exports.findFromManifest = exports.getManifestFromRepo = exports.findAllVersions = exports.find = exports.cacheFile = exports.cacheDir = exports.extractZip = exports.extractXar = exports.extractTar = exports.extract7z = exports.downloadTool = exports.HTTPError = void 0;
-const core = __importStar(__nccwpck_require__(9935));
-const io = __importStar(__nccwpck_require__(2725));
+const core = __importStar(__nccwpck_require__(5127));
+const io = __importStar(__nccwpck_require__(2864));
 const fs = __importStar(__nccwpck_require__(7147));
-const mm = __importStar(__nccwpck_require__(7936));
+const mm = __importStar(__nccwpck_require__(9024));
 const os = __importStar(__nccwpck_require__(2037));
 const path = __importStar(__nccwpck_require__(1017));
-const httpm = __importStar(__nccwpck_require__(3658));
-const semver = __importStar(__nccwpck_require__(7163));
+const httpm = __importStar(__nccwpck_require__(6227));
+const semver = __importStar(__nccwpck_require__(1156));
 const stream = __importStar(__nccwpck_require__(2781));
 const util = __importStar(__nccwpck_require__(3837));
 const assert_1 = __nccwpck_require__(9491);
-const v4_1 = __importDefault(__nccwpck_require__(4559));
-const exec_1 = __nccwpck_require__(3409);
-const retry_helper_1 = __nccwpck_require__(721);
+const v4_1 = __importDefault(__nccwpck_require__(9872));
+const exec_1 = __nccwpck_require__(2049);
+const retry_helper_1 = __nccwpck_require__(6429);
 class HTTPError extends Error {
     constructor(httpStatusCode) {
         super(`Unexpected HTTP response: ${httpStatusCode}`);
@@ -3909,7 +3909,7 @@ function _unique(values) {
 
 /***/ }),
 
-/***/ 6993:
+/***/ 9205:
 /***/ ((module) => {
 
 /**
@@ -3942,7 +3942,7 @@ module.exports = bytesToUuid;
 
 /***/ }),
 
-/***/ 3480:
+/***/ 5975:
 /***/ ((module, __unused_webpack_exports, __nccwpck_require__) => {
 
 // Unique ID creation requires a high quality random # generator.  In node.js
@@ -3957,11 +3957,11 @@ module.exports = function nodeRNG() {
 
 /***/ }),
 
-/***/ 4559:
+/***/ 9872:
 /***/ ((module, __unused_webpack_exports, __nccwpck_require__) => {
 
-var rng = __nccwpck_require__(3480);
-var bytesToUuid = __nccwpck_require__(6993);
+var rng = __nccwpck_require__(5975);
+var bytesToUuid = __nccwpck_require__(9205);
 
 function v4(options, buf, offset) {
   var i = buf && offset || 0;
@@ -3993,7 +3993,7 @@ module.exports = v4;
 
 /***/ }),
 
-/***/ 7163:
+/***/ 1156:
 /***/ ((module, exports) => {
 
 exports = module.exports = SemVer
@@ -5596,15 +5596,15 @@ function coerce (version, options) {
 
 /***/ }),
 
-/***/ 7477:
+/***/ 7265:
 /***/ ((module, __unused_webpack_exports, __nccwpck_require__) => {
 
-module.exports = __nccwpck_require__(8162);
+module.exports = __nccwpck_require__(2686);
 
 
 /***/ }),
 
-/***/ 8162:
+/***/ 2686:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -5875,7 +5875,7 @@ exports.debug = debug; // for test
 
 /***/ }),
 
-/***/ 1368:
+/***/ 9267:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -5938,29 +5938,29 @@ Object.defineProperty(exports, "parse", ({
   }
 }));
 
-var _v = _interopRequireDefault(__nccwpck_require__(3258));
+var _v = _interopRequireDefault(__nccwpck_require__(940));
 
-var _v2 = _interopRequireDefault(__nccwpck_require__(2559));
+var _v2 = _interopRequireDefault(__nccwpck_require__(7052));
 
-var _v3 = _interopRequireDefault(__nccwpck_require__(2872));
+var _v3 = _interopRequireDefault(__nccwpck_require__(1545));
 
-var _v4 = _interopRequireDefault(__nccwpck_require__(5034));
+var _v4 = _interopRequireDefault(__nccwpck_require__(483));
 
-var _nil = _interopRequireDefault(__nccwpck_require__(6051));
+var _nil = _interopRequireDefault(__nccwpck_require__(4418));
 
-var _version = _interopRequireDefault(__nccwpck_require__(6630));
+var _version = _interopRequireDefault(__nccwpck_require__(6433));
 
-var _validate = _interopRequireDefault(__nccwpck_require__(6879));
+var _validate = _interopRequireDefault(__nccwpck_require__(659));
 
-var _stringify = _interopRequireDefault(__nccwpck_require__(2992));
+var _stringify = _interopRequireDefault(__nccwpck_require__(4886));
 
-var _parse = _interopRequireDefault(__nccwpck_require__(3783));
+var _parse = _interopRequireDefault(__nccwpck_require__(8517));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
 /***/ }),
 
-/***/ 1102:
+/***/ 4576:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -5989,7 +5989,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 6051:
+/***/ 4418:
 /***/ ((__unused_webpack_module, exports) => {
 
 
@@ -6003,7 +6003,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 3783:
+/***/ 8517:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6013,7 +6013,7 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _validate = _interopRequireDefault(__nccwpck_require__(6879));
+var _validate = _interopRequireDefault(__nccwpck_require__(659));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6054,7 +6054,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 4557:
+/***/ 3310:
 /***/ ((__unused_webpack_module, exports) => {
 
 
@@ -6068,7 +6068,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 160:
+/***/ 1710:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6098,7 +6098,7 @@ function rng() {
 
 /***/ }),
 
-/***/ 4850:
+/***/ 8315:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6127,7 +6127,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 2992:
+/***/ 4886:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6137,7 +6137,7 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _validate = _interopRequireDefault(__nccwpck_require__(6879));
+var _validate = _interopRequireDefault(__nccwpck_require__(659));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6172,7 +6172,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 3258:
+/***/ 940:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6182,9 +6182,9 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _rng = _interopRequireDefault(__nccwpck_require__(160));
+var _rng = _interopRequireDefault(__nccwpck_require__(1710));
 
-var _stringify = _interopRequireDefault(__nccwpck_require__(2992));
+var _stringify = _interopRequireDefault(__nccwpck_require__(4886));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6285,7 +6285,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 2559:
+/***/ 7052:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6295,9 +6295,9 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _v = _interopRequireDefault(__nccwpck_require__(810));
+var _v = _interopRequireDefault(__nccwpck_require__(4837));
 
-var _md = _interopRequireDefault(__nccwpck_require__(1102));
+var _md = _interopRequireDefault(__nccwpck_require__(4576));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6307,7 +6307,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 810:
+/***/ 4837:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6318,9 +6318,9 @@ Object.defineProperty(exports, "__esModule", ({
 exports["default"] = _default;
 exports.URL = exports.DNS = void 0;
 
-var _stringify = _interopRequireDefault(__nccwpck_require__(2992));
+var _stringify = _interopRequireDefault(__nccwpck_require__(4886));
 
-var _parse = _interopRequireDefault(__nccwpck_require__(3783));
+var _parse = _interopRequireDefault(__nccwpck_require__(8517));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6391,7 +6391,7 @@ function _default(name, version, hashfunc) {
 
 /***/ }),
 
-/***/ 2872:
+/***/ 1545:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6401,9 +6401,9 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _rng = _interopRequireDefault(__nccwpck_require__(160));
+var _rng = _interopRequireDefault(__nccwpck_require__(1710));
 
-var _stringify = _interopRequireDefault(__nccwpck_require__(2992));
+var _stringify = _interopRequireDefault(__nccwpck_require__(4886));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6434,7 +6434,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 5034:
+/***/ 483:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6444,9 +6444,9 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _v = _interopRequireDefault(__nccwpck_require__(810));
+var _v = _interopRequireDefault(__nccwpck_require__(4837));
 
-var _sha = _interopRequireDefault(__nccwpck_require__(4850));
+var _sha = _interopRequireDefault(__nccwpck_require__(8315));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6456,7 +6456,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 6879:
+/***/ 659:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6466,7 +6466,7 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _regex = _interopRequireDefault(__nccwpck_require__(4557));
+var _regex = _interopRequireDefault(__nccwpck_require__(3310));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6479,7 +6479,7 @@ exports["default"] = _default;
 
 /***/ }),
 
-/***/ 6630:
+/***/ 6433:
 /***/ ((__unused_webpack_module, exports, __nccwpck_require__) => {
 
 
@@ -6489,7 +6489,7 @@ Object.defineProperty(exports, "__esModule", ({
 }));
 exports["default"] = void 0;
 
-var _validate = _interopRequireDefault(__nccwpck_require__(6879));
+var _validate = _interopRequireDefault(__nccwpck_require__(659));
 
 function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
@@ -6625,7 +6625,7 @@ module.exports = __WEBPACK_EXTERNAL_createRequire(import.meta.url)("util");
 
 /***/ }),
 
-/***/ 8405:
+/***/ 5324:
 /***/ ((__webpack_module__, __unused_webpack___webpack_exports__, __nccwpck_require__) => {
 
 var _actions_core__WEBPACK_IMPORTED_MODULE_0___namespace_cache;
@@ -6635,10 +6635,10 @@ var fs__WEBPACK_IMPORTED_MODULE_4___namespace_cache;
 var os__WEBPACK_IMPORTED_MODULE_6___namespace_cache;
 var process__WEBPACK_IMPORTED_MODULE_7___namespace_cache;
 __nccwpck_require__.a(__webpack_module__, async (__webpack_handle_async_dependencies__, __webpack_async_result__) => { try {
-/* harmony import */ var _actions_core__WEBPACK_IMPORTED_MODULE_0__ = __nccwpck_require__(9935);
-/* harmony import */ var _actions_exec__WEBPACK_IMPORTED_MODULE_1__ = __nccwpck_require__(3409);
-/* harmony import */ var _actions_http_client__WEBPACK_IMPORTED_MODULE_2__ = __nccwpck_require__(3658);
-/* harmony import */ var _actions_tool_cache__WEBPACK_IMPORTED_MODULE_3__ = __nccwpck_require__(2275);
+/* harmony import */ var _actions_core__WEBPACK_IMPORTED_MODULE_0__ = __nccwpck_require__(5127);
+/* harmony import */ var _actions_exec__WEBPACK_IMPORTED_MODULE_1__ = __nccwpck_require__(2049);
+/* harmony import */ var _actions_http_client__WEBPACK_IMPORTED_MODULE_2__ = __nccwpck_require__(6227);
+/* harmony import */ var _actions_tool_cache__WEBPACK_IMPORTED_MODULE_3__ = __nccwpck_require__(9348);
 /* harmony import */ var fs__WEBPACK_IMPORTED_MODULE_4__ = __nccwpck_require__(7147);
 /* harmony import */ var module__WEBPACK_IMPORTED_MODULE_5__ = __nccwpck_require__(8188);
 /* harmony import */ var os__WEBPACK_IMPORTED_MODULE_6__ = __nccwpck_require__(2037);
@@ -6859,6 +6859,6 @@ __webpack_async_result__();
 /******/ // startup
 /******/ // Load entry module and return exports
 /******/ // This entry module used 'module' so it can't be inlined
-/******/ var __webpack_exports__ = __nccwpck_require__(8405);
+/******/ var __webpack_exports__ = __nccwpck_require__(5324);
 /******/ __webpack_exports__ = await __webpack_exports__;
 /******/ 
diff --git a/dist/main.cjs b/dist/main.cjs
index 253f2a8..69a8fda 100644
--- a/dist/main.cjs
+++ b/dist/main.cjs
@@ -1,4 +1,4 @@
-// Generated by dart2js (NullSafetyMode.sound, csp, deferred-serialization, intern-composite-values), the Dart to JavaScript compiler version: 3.1.0-296.0.dev.
+// Generated by dart2js (NullSafetyMode.sound, csp, deferred-serialization, intern-composite-values), the Dart to JavaScript compiler version: 3.2.0-42.0.dev.
 // The code supports the following hooks:
 // dartPrint(message):
 //    if this function is defined it is called instead of the Dart [print]
@@ -753,7 +753,7 @@
       }
       return result;
     },
-    invokeClosure(closure, numberOfArguments, arg1, arg2, arg3, arg4) {
+    _invokeClosure(closure, numberOfArguments, arg1, arg2, arg3, arg4) {
       type$.Function._as(closure);
       switch (A._asInt(numberOfArguments)) {
         case 0:
@@ -773,13 +773,38 @@
       var $function = closure.$identity;
       if (!!$function)
         return $function;
-      $function = function(closure, arity, invoke) {
+      $function = A.convertDartClosureToJSUncached(closure, arity);
+      closure.$identity = $function;
+      return $function;
+    },
+    convertDartClosureToJSUncached(closure, arity) {
+      var entry;
+      switch (arity) {
+        case 0:
+          entry = closure.call$0;
+          break;
+        case 1:
+          entry = closure.call$1;
+          break;
+        case 2:
+          entry = closure.call$2;
+          break;
+        case 3:
+          entry = closure.call$3;
+          break;
+        case 4:
+          entry = closure.call$4;
+          break;
+        default:
+          entry = null;
+      }
+      if (entry != null)
+        return entry.bind(closure);
+      return function(closure, arity, invoke) {
         return function(a1, a2, a3, a4) {
           return invoke(closure, arity, a1, a2, a3, a4);
         };
-      }(closure, arity, A.invokeClosure);
-      closure.$identity = $function;
-      return $function;
+      }(closure, arity, A._invokeClosure);
     },
     Closure_fromTearOff(parameters) {
       var $prototype, $constructor, t2, trampoline, applyTrampoline, i, stub, stub0, stubName, stubCallName,
diff --git a/dist/sig.txt b/dist/sig.txt
index 8fd3970..fe3e7be 100644
--- a/dist/sig.txt
+++ b/dist/sig.txt
@@ -1 +1 @@
-5824C997FA8A298F08447E92FF5FEF52
+F500C84960FB4A579CD093BAC4BD0E9E
diff --git a/lib/node/actions/core.dart b/lib/node/actions/core.dart
index 3c8a044..575f6cc 100644
--- a/lib/node/actions/core.dart
+++ b/lib/node/actions/core.dart
@@ -8,11 +8,7 @@ import 'dart:js_interop';
 external Core get core;
 
 @JS()
-inline class Core {
-  final JSObject obj;
-
-  Core(this.obj);
-
+extension type Core (JSObject obj) {
   external String getInput(String name);
 
   external void setOutput(String name, String value);
diff --git a/lib/node/actions/exec.dart b/lib/node/actions/exec.dart
index 16a51de..a84e23c 100644
--- a/lib/node/actions/exec.dart
+++ b/lib/node/actions/exec.dart
@@ -8,11 +8,7 @@ import 'dart:js_interop';
 external Exec get exec;
 
 @JS()
-inline class Exec {
-  final JSObject obj;
-
-  Exec(this.obj);
-
+extension type Exec (JSObject obj) {
   /// Exec a command.
   ///
   /// Output will be streamed to the live console. Returns promise with return
diff --git a/lib/node/actions/http_client.dart b/lib/node/actions/http_client.dart
index 579fa99..22d7273 100644
--- a/lib/node/actions/http_client.dart
+++ b/lib/node/actions/http_client.dart
@@ -5,9 +5,7 @@
 import 'dart:js_interop';
 
 @JS()
-inline class HttpClient {
-  final JSObject obj;
-
+extension type HttpClient._(JSObject obj) {
   external HttpClient(
     String userAgent, [
     JSArray? handlers,
diff --git a/lib/node/actions/tool_cache.dart b/lib/node/actions/tool_cache.dart
index dd6c906..b5eee35 100644
--- a/lib/node/actions/tool_cache.dart
+++ b/lib/node/actions/tool_cache.dart
@@ -8,11 +8,7 @@ import 'dart:js_interop';
 external ToolCache get toolCache;
 
 @JS()
-inline class ToolCache {
-  final JSObject obj;
-
-  ToolCache(this.obj);
-
+extension type ToolCache (JSObject obj) {
   /// Finds the path to a tool version in the local installed tool cache.
   ///
   /// @param toolName      name of the tool
diff --git a/lib/node/fs.dart b/lib/node/fs.dart
index a0196fe..05d58ce 100644
--- a/lib/node/fs.dart
+++ b/lib/node/fs.dart
@@ -10,11 +10,7 @@ import 'dart:js_interop';
 external FileSystem get fs;
 
 @JS()
-inline class FileSystem {
-  final JSObject fileSystem;
-
-  FileSystem(this.fileSystem);
-
+extension type FileSystem (JSObject fileSystem) {
   /// Whether the [path] exists, false otherwise.
   external bool existsSync(String path);
 
diff --git a/lib/node/os.dart b/lib/node/os.dart
index a2e670b..24f09be 100644
--- a/lib/node/os.dart
+++ b/lib/node/os.dart
@@ -10,11 +10,7 @@ import 'dart:js_interop';
 external OS get os;
 
 @JS()
-inline class OS {
-  final JSObject os;
-
-  OS(this.os);
-
+extension type OS (JSObject obj) {
   @JS('arch')
   external String _arch();
 
diff --git a/lib/node/process.dart b/lib/node/process.dart
index 57f1985..fc41f9f 100644
--- a/lib/node/process.dart
+++ b/lib/node/process.dart
@@ -11,11 +11,7 @@ import 'dart:js_util';
 external Process get process;
 
 @JS()
-inline class Process {
-  final JSObject process;
-
-  Process(this.process);
-
+extension type Process (JSObject obj) {
   @JS('env')
   // Map<String, String?>
   external JSObject _env;
diff --git a/pubspec.yaml b/pubspec.yaml
index 2dc5844..f7b23e9 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,7 +4,7 @@ description: The setup-dart GitHub Action - download and setup the Dart SDK.
 publish_to: none
 
 environment:
-  sdk: ^3.1.0-0
+  sdk: ^3.2.0-0
 
 dependencies:
   path: ^1.8.0