pkg/dart2wasm/test/self_compile_test.dart

// 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 'dart:io';
import 'dart:typed_data';

import 'package:path/path.dart' as path;

import 'util.dart';

Future main() async {
  if (!Platform.isLinux && !Platform.isMacOS) return;

  final benchmarkFile = 'pkg/dart2wasm/benchmark/self_compile_benchmark.dart';

  await withTempDir((String tempDir) async {
    final outFilename = path.join(tempDir, 'out');
    final outVmFilename = path.join(tempDir, 'out.vm');
    final outDart2WasmFilename = path.join(tempDir, 'out.dart2wasm');
    final outFile = File(outFilename);

    // Run [benchmarkFile] via VM & capture output.
    await run([Platform.executable, benchmarkFile, outFilename]);
    final vmBytes = outFile.readAsBytesSync();
    outFile.renameSync(outVmFilename);

    // Run [benchmarkFile] via Dart2Wasm+D8 & capture output.
    final selfCompiler = path.join(tempDir, 'self_compile_benchmark.wasm');
    await run([
      Platform.executable,
      'compile',
      'wasm',
      '-O2',
      '--no-strip-wasm',
      '--no-minify',
      benchmarkFile,
      '-o',
      selfCompiler
    ]);
    await run(['pkg/dart2wasm/tool/run_benchmark', selfCompiler, outFilename]);
    final wasmBytes = outFile.readAsBytesSync();
    outFile.renameSync(outDart2WasmFilename);

    expectEqualBytes(vmBytes, wasmBytes);
  });
}

void expectEqualBytes(Uint8List a, Uint8List b) {
  if (a.length != b.length) {
    throw 'Mismatch in length ${a.length} vs ${b.length}';
  }
  for (int i = 0; i < a.length; ++i) {
    if (a[i] != b[i]) {
      throw 'Mismatch at offset $i ${a[i]} vs ${b[i]}';
    }
  }
}