From 670b5bd8e714a1fd2bd137aa2c5b36760b8ce89b Mon Sep 17 00:00:00 2001
From: Dan Field <dnfield@google.com>
Date: Mon, 16 Oct 2023 14:55:06 -0700
Subject: [PATCH] Fix `Platform.script` for flutter_tester
 (flutter/engine#46911)

This addresses the problem in https://github.com/flutter/flutter/issues/12847 which changed slightly over time.

Today, `Platform.script` does not give an empty `file` URI, it gives something like `file://path/to/package/main.dart` _regardless of how the file is actually named_.

After this change, it will give the absolute path to the file being run under test.

So before this change, the new test would have a URI like

```
file:///Users/dnfield/src/flutter/engine/src/main.dart
```

And now it has

```
file:///Users/dnfield/src/flutter/engine/src/out/host_debug_unopt_arm64/gen/platform_test.dart.dill
```

This is going to be helpful in generating relative paths from the test file.
---
 engine/src/flutter/shell/testing/tester_main.cc    |  1 +
 engine/src/flutter/testing/dart/BUILD.gn           |  1 +
 engine/src/flutter/testing/dart/platform_test.dart | 14 ++++++++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 engine/src/flutter/testing/dart/platform_test.dart

diff --git a/engine/src/flutter/shell/testing/tester_main.cc b/engine/src/flutter/shell/testing/tester_main.cc
index 607dc6a6a6..8b1b49131b 100644
--- a/engine/src/flutter/shell/testing/tester_main.cc
+++ b/engine/src/flutter/shell/testing/tester_main.cc
@@ -526,6 +526,7 @@ int main(int argc, char* argv[]) {
     // it as a positional argument instead.
     settings.application_kernel_asset = command_line.positional_args()[0];
   }
+  settings.advisory_script_uri = settings.application_kernel_asset;
 
   if (settings.application_kernel_asset.empty()) {
     FML_LOG(ERROR) << "Dart kernel file not specified.";
diff --git a/engine/src/flutter/testing/dart/BUILD.gn b/engine/src/flutter/testing/dart/BUILD.gn
index 2e1bb1ad38..f59b6166c6 100644
--- a/engine/src/flutter/testing/dart/BUILD.gn
+++ b/engine/src/flutter/testing/dart/BUILD.gn
@@ -38,6 +38,7 @@ tests = [
   "paragraph_test.dart",
   "path_test.dart",
   "picture_test.dart",
+  "platform_test.dart",
   "platform_view_test.dart",
   "plugin_utilities_test.dart",
   "semantics_test.dart",
diff --git a/engine/src/flutter/testing/dart/platform_test.dart b/engine/src/flutter/testing/dart/platform_test.dart
new file mode 100644
index 0000000000..5ba620ddcc
--- /dev/null
+++ b/engine/src/flutter/testing/dart/platform_test.dart
@@ -0,0 +1,14 @@
+// Copyright 2013 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 'dart:io';
+
+import 'package:litetest/litetest.dart';
+
+void main() {
+  test('Platform.script has right URI', () async {
+    // Platform.script should look like file:///path/to/engine/src/out/variant/gen/platform_test.dart.dill
+    expect(Platform.script.path, endsWith('gen/platform_test.dart.dill'));
+  });
+}