Compatibility with AOT analysis_server

[srawlins]

The Dart analysis server snapshot (bin/snapshtos/analysis_server.dart.snapshot) will soon be compiled and run as an AOT snapshot (bin/snapshtos/analysis_server_aot.dart.snapshot). (Maybe Dart 3.9.)

custom_lint seems to be incompatible with this change, at least in one place:

dart_custom_lint/packages/custom_lint/lib/src/workspace.dart

Line 761 in 3aaed0c

Future<void> runPubGet(Directory tempDir) async {

runPubGet uses Platform.resolvedExecutable, something like ${Platform.resolvedExecutable} pub get. But when it is running from the AOT-compiled analysis server, the resolved executable is dartaotruntime (instead of dart). dartaotruntime cannot be used to run pub.

custom_lint should instead look to find the dart (or dart.exe) binary next to Platform.resolvedExecutable. I am not sure if there is a vetted, canonical way of doing so. But it isn't too hard in a few lines to get the sibling binary file.

As for testing, maybe not easy 😅 I have a WIP CL that allows for running analysis server as AOT. I can probably test a fix locally.

[srawlins]

And in case it is important, GitHub search finds one other non-test use of resolvedExecutable in custom_lint. https://github.com/search?q=repo%3Ainvertase%2Fdart_custom_lint%20resolvedexecutable&type=code

[srawlins]

This patch seems to make AOT snapshots fully supported :D

$ git diff
diff --git a/packages/custom_lint/lib/src/workspace.dart b/packages/custom_lint/lib/src/workspace.dart
index 2d5bfd8..511d6c0 100644
--- a/packages/custom_lint/lib/src/workspace.dart
+++ b/packages/custom_lint/lib/src/workspace.dart
@@ -759,7 +759,8 @@ publish_to: 'none'

   /// Run "pub get" in the client project.
   Future<void> runPubGet(Directory tempDir) async {
-    final command = Platform.resolvedExecutable;
+    final sdkDir = dirname(Platform.resolvedExecutable);
+    final command = join(sdkDir, Platform.isWindows ? 'dart.exe' : 'dart');
     final result = await runProcess(
       command,
       const ['pub', 'get'],

[rrousselGit]

I wonder if we still need to rely on Platform.resolvedExecutable at all nowadays.

It seems like dart pub get correctly handles Flutter now. From what I remember, Platform was primarily used as an automatic switch between flutter pub get vs dart pub get.

[srawlins]

@rrousselGit there is now a Flutter beta release in which you can test custom_lint against the analysis server compiled as an AOT snapshot. I have instructions for command-line and VS Code; not sure about IntelliJ.

The functionality is first available in Flutter 3.34.0-0.0.pre, the beta that was released this morning. Download here: https://docs.flutter.dev/install/archive#beta-channel

These command-line tools are available with an AOT snapshot opt-in:

• dart analyze --use-aot-snapshot (dart analyze by itself will use the JIT snapshot, which has been shipping with Flutter for years)
• dart fix --use-aot-snapshot (dart fix by itself will use the JIT snapshot)

In addition, to instruct VS Code to launch the analysis server as an AOT snapshot, you can specify the dart.analyzerAdditionalArgs setting, in either a Workspace settings JSON file, or the User settings JSON file. In that setting list, include "--use-aot-snapshot" (e.g. "dart.analyzerAdditionalArgs": ["--use-aot-snapshot"]. (VS Code launches the analysis server with dart language-server, and with this flag it will use dart language-server --use-aot-snapshot.)

The plan is to flip the flag with the next stable release, which I think is Flutter 3.35.0. So in that release, all three commands, including the dart language-server command used by IDEs, will launch the analysis server as an AOT snapshot by default. There will be an escape hatch, which is passing a --no-use-aot-snapshot flag, for cases where additional time or analyzer plugin releases are required to make anything compatible that wasn't already.

It would be good to test custom_lint against Flutter 3.34.0-0.0.pre with the AOT snapshot modes, before they are flipped to be enabled by default.