dart-lang · kevmoo · May 15, 2026 · May 15, 2026 · May 15, 2026 · May 15, 2026
diff --git a/server/simple/README.md b/server/simple/README.md
@@ -1,3 +1,5 @@
+![Welcome Dart Server](public/welcome_dart_server.png)
+
 A simple Dart HTTP server using [package:shelf](https://pub.dev/packages/shelf).
 
 - Listens on "any IP" (0.0.0.0) instead of loop-back (localhost, 127.0.0.1) to
@@ -28,13 +30,13 @@ or follow
 
 ### With OS-only runtime
 
-Use [`tool/deploy_source.sh`](tool/deploy_source.sh) to build and 
+Use [`tool/deploy_source.dart`](tool/deploy_source.dart) to build and
 deploy using the
 [OS-only runtimes](https://docs.cloud.google.com/docs/buildpacks/osonly)
 feature.
 
 > [!NOTE]
-> As of January 2026, this feature is in "Preview" and
+> As of May 2026, this feature is in "Preview" and
 > requires the ["beta" gcloud component][gcloud-beta].
 
 [cloud-beta]: https://docs.cloud.google.com/sdk/docs/components#alpha_and_beta_components
diff --git a/server/simple/bin/server.dart b/server/simple/bin/server.dart
@@ -14,7 +14,7 @@ import 'package:shelf_static/shelf_static.dart' as shelf_static;
 Future<void> main() async {
   // If the "PORT" environment variable is set, listen to it. Otherwise, 8080.
   // https://cloud.google.com/run/docs/reference/container-contract#port
-  final port = int.parse(Platform.environment['PORT'] ?? '8080');
+  final port = int.tryParse(Platform.environment['PORT'] ?? '8080') ?? 8080;
 
   // See https://pub.dev/documentation/shelf/latest/shelf/Cascade-class.html
   final cascade = Cascade()
@@ -63,8 +63,11 @@ String _jsonEncode(Object? data) =>
 const _jsonHeaders = {'content-type': 'application/json'};
 
 Response _sumHandler(Request request, String a, String b) {
-  final aNum = int.parse(a);
-  final bNum = int.parse(b);
+  final aNum = int.tryParse(a);
+  final bNum = int.tryParse(b);
+  if (aNum == null || bNum == null) {
+    return Response.badRequest(body: 'Invalid integer arguments');
+  }
   return Response.ok(
     _jsonEncode({'a': aNum, 'b': bNum, 'sum': aNum + bNum}),
     headers: {

diff --git a/server/simple/public/dashland.jpeg b/server/simple/public/dashland.jpeg
diff --git a/server/simple/public/index.html b/server/simple/public/index.html
@@ -7,57 +7,36 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <link rel="icon" sizes="64x64" href="64.png">
   <title>pkg:shelf example</title>
+  <link rel="stylesheet" href="style.css">
 </head>
 
-<style>
-  body {
-    display: flex;
-    flex-direction: column;
-    justify-content: center;
-    align-items: center;
-    font-family: sans-serif;
-  }
-
-  p {
-    margin-top: 1rem;
-    font-size: large;
-    max-width: 600px;
-  }
-
-  img {
-    max-width: 70vw;
-  }
-
-  code {
-    background: #eee;
-    padding: 3px;
-  }
-</style>
-
 <body>
-<h1>pkg:shelf example</h1>
-<img src="/dashland.jpeg" alt="Dashland">
-<p>This file is being served by <a
-    href="https://pub.dev/packages/shelf_static">package:shelf_static</a> from the
-  <code>/public</code> directory.</p>
-<!-- TODO: Link to new pkg:shelf docs once https://github.com/dart-lang/site-www/issues/3058 is fixed -->
-<p>This app uses <a
-    href="https://pub.dev/packages/shelf_router">package:shelf_router</a> to define several
-  code-based handlers:</p>
-<ul>
-  <li><a href="/helloworld">/helloworld</a></li>
-  <li><a href="/time">/time</a>
-  <li><a href="/info.json">/info.json</a> (also embedded as an <code>iframe</code> below)</li>
-  <li><code>/sum/&lt;a|[0-9]+&gt;/&lt;b|[0-9]+&gt;</code></li>
-</ul>
-
-<p>
-  The last handler is defined with regular expressions to handle requests to <a href="/sum/1/2">/sum/1/2</a>
-  and <a href="/sum/35/7">/sum/35/7</a>,
-  but not <a href="/sum/bob/john">/sum/bob/john</a> or <a href="/sum/1/2/3">/sum/1/2/3</a>.
-<p>
-
-<iframe width="400" height="100" src="info.json"></iframe>
+  <img src="/welcome_dart_server.png" alt="Welcome Dart Server" width="519" height="300">
+  <p>This application is built using the following packages:</p>
+  <dl>
+    <dt><a href="https://pub.dev/packages/shelf">package:shelf</a></dt>
+    <dd>Provides the core HTTP server middleware and request/response handling.</dd>
+    <dt><a href="https://pub.dev/packages/shelf_static">package:shelf_static</a></dt>
+    <dd>Serves static files from the local filesystem (including this page and images from the <code>/public</code>
+      directory).</dd>
+    <dt><a href="https://pub.dev/packages/shelf_router">package:shelf_router</a></dt>
+    <dd>Defines dynamic route handlers and regular expression URL pattern matching.</dd>
+  </dl>
+
+  <p>The router defines several code-based handlers:</p>
+  <ul>
+    <li><a href="/helloworld">/helloworld</a><br>Returns plain text.
+    </li>
+    <li><a href="/time">/time</a><br>Returns <code>application/json</code> with the current UTC date and
+      time.</li>
+    <li><code>/sum/&lt;a|[0-9]+&gt;/&lt;b|[0-9]+&gt;</code><br>Uses regular expressions to handle
+      requests to <a href="/sum/1/2">/sum/1/2</a>
+      and <a href="/sum/35/7">/sum/35/7</a>, but not <a href="/sum/bob/john">/sum/bob/john</a>.
+    </li>
+    <li><a href="/info.json">/info.json</a><br>Returns the info.json shown in the iframe below.</li>
+  </ul>
+
+  <iframe width="650" height="300" src="info.json"></iframe>
 
 </body>
 

diff --git a/server/simple/public/style.css b/server/simple/public/style.css
@@ -0,0 +1,134 @@
+:root {
+  --bg-color: #f8fafc;
+  --text-color: #1e293b;
+  --link-color: #2563eb;
+  --link-hover: #1d4ed8;
+  --card-bg: #ffffff;
+  --border-color: #e2e8f0;
+  --code-bg: #f1f5f9;
+  --accent-color: #0284c7;
+}
+
+@media (prefers-color-scheme: dark) {
+  :root {
+    --bg-color: #0f172a;
+    --text-color: #f1f5f9;
+    --link-color: #38bdf8;
+    --link-hover: #7dd3fc;
+    --card-bg: #1e293b;
+    --border-color: #334155;
+    --code-bg: #0b0f19;
+    --accent-color: #38bdf8;
+  }
+}
+
+body {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
+    Oxygen, Ubuntu, Cantarell, sans-serif;
+  background-color: var(--bg-color);
+  color: var(--text-color);
+  margin: 0;
+  padding: 2rem 1rem;
+  line-height: 1.6;
+}
+
+p {
+  margin-top: 1rem;
+  font-size: 1.1rem;
+  max-width: 650px;
+  width: 100%;
+}
+
+a {
+  color: var(--link-color);
+  text-decoration: none;
+  font-weight: 500;
+  transition: color 0.2s ease-in-out;
+}
+
+a:hover {
+  color: var(--link-hover);
+  text-decoration: underline;
+}
+
+img {
+  max-width: 100%;
+  height: auto;
+  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1),
+    0 8px 10px -6px rgba(0, 0, 0, 0.1);
+  transition: transform 0.3s ease;
+}
+
+img:hover {
+  transform: scale(1.02);
+}
+
+code {
+  background-color: var(--code-bg);
+  padding: 0.2rem 0.4rem;
+  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
+  font-size: 0.95em;
+  color: var(--accent-color);
+}
+
+dl,
+ul {
+  background-color: var(--card-bg);
+  border: 1px solid var(--border-color);
+  padding: 1.5rem 2rem;
+  max-width: 650px;
+  width: 100%;
+  box-sizing: border-box;
+  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
+  margin: 1rem 0;
+}
+
+dt {
+  font-weight: 700;
+  font-size: 1.2rem;
+  margin-top: 1rem;
+  color: var(--link-color);
+}
+
+dt:first-child {
+  margin-top: 0;
+}
+
+dd {
+  margin-bottom: 1.2rem;
+  margin-left: 0;
+  padding-left: 1rem;
+  border-left: 3px solid var(--link-color);
+  color: var(--text-color);
+}
+
+ul {
+  list-style-type: none;
+  padding-left: 1.5rem;
+}
+
+li {
+  margin-bottom: 0.5rem;
+  position: relative;
+}
+
+li::before {
+  content: "•";
+  color: var(--link-color);
+  font-weight: bold;
+  display: inline-block;
+  width: 1em;
+  margin-left: -1em;
+}
+
+iframe {
+  border: 1px solid var(--border-color);
+  background-color: var(--card-bg);
+  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
+  margin-top: 2rem;
+  max-width: 100%;
+  box-sizing: border-box;
+}
diff --git a/server/simple/public/welcome_dart_server.png b/server/simple/public/welcome_dart_server.png
diff --git a/server/simple/pubspec.yaml b/server/simple/pubspec.yaml
@@ -10,7 +10,9 @@ dependencies:
   shelf_static: ^1.1.3
 
 dev_dependencies:
+  args: ^2.7.0
   http: ^1.6.0
   lints: ^6.0.0
+  path: ^1.9.0
   test: ^1.27.0
   test_process: ^2.1.1
diff --git a/server/simple/test/test_definitions.dart b/server/simple/test/test_definitions.dart
@@ -40,4 +40,17 @@ void runTests(
     expect(response.statusCode, 200);
     expect(response.body, contains('pkg:shelf example'));
   });
+
+  testServer('sum', (host) async {
+    var response = await get(Uri.parse('$host/sum/1/2'));
+    expect(response.statusCode, 200);
+    expect(response.body, contains('"sum": 3'));
+
+    // Test integer overflow / invalid integer handling.
+    response = await get(
+      Uri.parse('$host/sum/9999999999999999999999999999999999999999999/2'),
+    );
+    expect(response.statusCode, 400);
+    expect(response.body, 'Invalid integer arguments');
+  });
 }