[flutter_tools] Adds test of impellerc output file mode (#109190)

packages/flutter_tools/test/integration.shard/shader_compiler_test.dart

+// Copyright 2014 The Flutter Authors. 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:flutter_tools/src/base/file_system.dart';
+import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/build_system/targets/shader_compiler.dart';
+import 'package:flutter_tools/src/globals.dart' as globals;
+
+import '../src/common.dart';
+import '../src/context.dart';
+
+void main() {
+  late BufferLogger logger;
+
+  setUp(() {
+    logger = BufferLogger.test();
+  });
+
+  testUsingContext('impellerc .iplr output has correct permissions', () async {
+    if (globals.platform.isWindows) {
+      return;
+    }
+
+    final String flutterRoot = getFlutterRoot();
+    final String inkSparklePath = globals.fs.path.join(flutterRoot,
+      'packages', 'flutter', 'lib', 'src', 'material', 'shaders',
+      'ink_sparkle.frag');
+    final Directory tmpDir = globals.fs.systemTempDirectory.createTempSync(
+      'shader_compiler_test.',
+    );
+    final String inkSparkleOutputPath = globals.fs.path.join(
+      tmpDir.path, 'ink_sparkle.frag',
+    );
+
+    final ShaderCompiler shaderCompiler = ShaderCompiler(
+      processManager: globals.processManager,
+      logger: logger,
+      fileSystem: globals.fs,
+      artifacts: globals.artifacts!,
+    );
+    final bool compileResult = await shaderCompiler.compileShader(
+      input: globals.fs.file(inkSparklePath),
+      outputPath: inkSparkleOutputPath,
+      target: ShaderTarget.sksl,
+    );
+    final File resultFile = globals.fs.file(inkSparkleOutputPath);
+
+
+    expect(compileResult, true);
+    expect(resultFile.existsSync(), true);
+
+    final int expectedMode = int.parse('644', radix: 8);
+    expect(resultFile.statSync().mode & expectedMode, equals(expectedMode));
+  });
+}