[tool] Fix IP parsing by using Uri constructor (flutter#178083)

Also DRY'd up use of `"any"` constant is several places.

Fixes flutter#178082

Author: kevmoo

packages/flutter_tools/lib/src/isolated/web_asset_server.dart

@@ -207,8 +207,8 @@ class WebAssetServer implements AssetReader {
     if (ddcModuleSystem) {
       assert(canaryFeatures);
     }
-    InternetAddress address;
-    if (hostname == 'any') {
+    final InternetAddress address;
+    if (hostname == webDevAnyHostDefault) {
       address = InternetAddress.anyIPv4;
     } else {
       address = (await InternetAddress.lookup(hostname)).first;
@@ -258,14 +258,15 @@ class WebAssetServer implements AssetReader {
       fileSystem: fileSystem,
     );
     final int selectedPort = server.selectedPort;
-    var url = '$hostname:$selectedPort';
-    if (hostname == 'any') {
-      url = 'localhost:$selectedPort';
-    }
-    server._baseUri = Uri.http(url, server.basePath);
-    if (tlsCertPath != null && tlsCertKeyPath != null) {
-      server._baseUri = Uri.https(url, server.basePath);
-    }
+
+    final cleanHost = hostname == webDevAnyHostDefault ? 'localhost' : hostname;
+    final scheme = tlsCertPath != null && tlsCertKeyPath != null ? 'https' : 'http';
+    server._baseUri = Uri(
+      scheme: scheme,
+      host: cleanHost,
+      port: selectedPort,
+      path: server.basePath,
+    );
     if (testMode) {
       return server;
     }

packages/flutter_tools/lib/src/web/devfs_config.dart

@@ -14,6 +14,11 @@ import '../base/os.dart';
 import 'devfs_proxy.dart';
 
 const webDevServerConfigFilePath = 'web_dev_config.yaml';
+
+/// Represents the default value for the web dev server.
+///
+/// Maps to `localhost` and/or `127.0.0.1`.
+const webDevAnyHostDefault = 'any';
 const _kLogEntryPrefix = '[WebDevServer]';
 const _kServer = 'server';
 const _kName = 'name';
@@ -41,7 +46,7 @@ T? _validateType<T>({required Object? value, required String fieldName}) {
 class WebDevServerConfig {
   const WebDevServerConfig({
     this.headers = const <String, String>{},
-    this.host = 'any',
+    this.host = webDevAnyHostDefault,
     this.port = 0,
     this.https,
     this.proxy = const <ProxyRule>[],
@@ -97,7 +102,7 @@ class WebDevServerConfig {
 
     return WebDevServerConfig(
       headers: headers,
-      host: host ?? 'any',
+      host: host ?? webDevAnyHostDefault,
       port: port ?? 0,
       https: https == null ? null : HttpsConfig.fromYaml(https),
       proxy: proxyRules,

packages/flutter_tools/test/general.shard/web/devfs_web_test.dart

@@ -1308,6 +1308,7 @@ void main() {
       final String dummyCertPath = globals.fs.path.join(dataPath, 'tls_cert', 'dummy-cert.pem');
       final String dummyCertKeyPath = globals.fs.path.join(dataPath, 'tls_cert', 'dummy-key.pem');
       final webDevServerConfig = WebDevServerConfig(
+        host: '::1',
         https: HttpsConfig(certPath: dummyCertPath, certKeyPath: dummyCertKeyPath),
       );
       final webDevFS = WebDevFS(
@@ -1341,6 +1342,8 @@ void main() {
 
       // Ensure the connection established is secure
       expect(uri.scheme, 'https');
+      // Ensure that the host correctly support IPv6
+      expect(uri.host, '::1');
 
       await webDevFS.destroy();
     }, overrides: <Type, Generator>{Artifacts: () => Artifacts.test()}),