http_client.dart

// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:js_interop';

import 'package:js/js.dart';

@JS()
external HttpClient get httpClient;

@JS()
// @staticInterop
class HttpClient {
  external HttpClient(String userAgent, List handlers, Map requestOptions);
}

extension HttpClientExtension on HttpClient {
  // JSPromise<JSObject>
  external JSPromise getJson(JSString requestUrl);
}

main.dart

Future<String?> latestPublishedVersion(String channel, String flavor) async {
  final url = 'https://storage.googleapis.com/dart-archive/channels/'
      '$channel/$flavor/latest/VERSION';

  final http = HttpClient('setup-dart', [], {
    'allowRedirects': true,
    'maxRedirects': 3,
    'allowRetries': true,
    'maxRetries': 3,
  });

  JSObject? result = await promiseToFuture(http.getJson(url));
  return result == null ? null : getProperty(result, 'version');
}

main.mjs

import * as core from '@actions/core';
import * as exec from '@actions/exec';
import * as httpClient from '@actions/http-client';
import * as toolCache from '@actions/tool-cache';
import * as fs from 'fs';
import * as module from 'module';
import * as os from 'os';
import * as process from 'process';

const require = module.createRequire(import.meta.url);

// Setup properties for JS interop in Dart.

globalThis.self = globalThis;
globalThis.core = core;
globalThis.exec = exec;
globalThis.httpClient = httpClient;
globalThis.toolCache = toolCache;
globalThis.fs = fs;
globalThis.os = os;
globalThis.process = process;
globalThis.location = { href: `file://${process.cwd()}/`}

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