[code_assets] Add sqlite example (#2533)

Author: dcharkes

pkgs/code_assets/example/build/sqlite/hook/build.dart

@@ -0,0 +1,32 @@
+// Copyright (c) 2025, 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 'package:code_assets/code_assets.dart';
+import 'package:hooks/hooks.dart';
+import 'package:logging/logging.dart';
+import 'package:native_toolchain_c/native_toolchain_c.dart';
+
+void main(List<String> args) async {
+  await build(args, (input, output) async {
+    if (input.config.buildCodeAssets) {
+      final cbuilder = CBuilder.library(
+        name: 'sqlite3',
+        assetName: 'src/third_party/sqlite3.g.dart',
+        sources: ['third_party/sqlite/sqlite3.c'],
+        defines: {
+          if (input.config.code.targetOS == OS.windows)
+            // Ensure symbols are exported in dll.
+            'SQLITE_API': '__declspec(dllexport)',
+        },
+      );
+      await cbuilder.run(
+        input: input,
+        output: output,
+        logger: Logger('')
+          ..level = Level.ALL
+          ..onRecord.listen((record) => print(record.message)),
+      );
+    }
+  });
+}

pkgs/code_assets/example/build/sqlite/lib/sqlite.dart

@@ -0,0 +1,5 @@
+// Copyright (c) 2025, 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.
+
+export 'src/sqlite.dart';

pkgs/code_assets/example/build/sqlite/lib/src/sqlite.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2025, 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 'package:ffi/ffi.dart';
+
+import 'third_party/sqlite3.g.dart';
+
+/// The machine's hostname.
+///
+/// Returns `null` if looking up the machines host name fails.
+String get version {
+  final nativeString = sqlite3_libversion();
+  return nativeString.cast<Utf8>().toDartString();
+}

pkgs/code_assets/example/build/sqlite/lib/src/third_party/sqlite3.g.dart

@@ -0,0 +1,15 @@
+// The author disclaims copyright to this source code.  In place of
+// a legal notice, here is a blessing:
+//
+//    May you do good and not evil.
+//    May you find forgiveness for yourself and forgive others.
+//    May you share freely, never taking more than you give.
+
+// AUTO GENERATED FILE, DO NOT EDIT.
+//
+// Generated by `package:ffigen`.
+// ignore_for_file: type=lint
+import 'dart:ffi' as ffi;
+
+@ffi.Native<ffi.Pointer<ffi.Char> Function()>()
+external ffi.Pointer<ffi.Char> sqlite3_libversion();

pkgs/code_assets/example/build/sqlite/pubspec.yaml

@@ -0,0 +1,23 @@
+name: sqlite
+description: An example for `package:code_assets` demonstrating how to bundle a locally built sqlite3 dynamic library.
+version: 0.1.0
+repository: https://github.com/dart-lang/native/tree/main/pkgs/sqlite
+
+publish_to: none
+
+resolution: workspace
+
+environment:
+  sdk: '>=3.9.0 <4.0.0'
+
+dependencies:
+  code_assets: any
+  ffi: ^2.1.4
+  hooks: any
+  logging: ^1.3.0
+  native_toolchain_c: any
+
+dev_dependencies:
+  ffigen: ^19.1.0
+  lints: ^6.0.0
+  test: ^1.25.15

pkgs/code_assets/example/build/sqlite/test/sqlite_test.dart

@@ -0,0 +1,12 @@
+// Copyright (c) 2025, 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 'package:sqlite/sqlite.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('version', () {
+    expect(version, equals('3.50.4'));
+  });
+}