Runtime exception on web when trying to DirectoryNode.clock

[rrousselGit]

Runtime exception on web when trying to DirectoryNode.clock

[rrousselGit]

I spent a bit of time investigating this issue, and it appears that the compiled code fails to read the fs property.

For some funky reason, editing RootNode.clock to:

  @override
  Clock get clock {
    print(fs);
    print(fs.clock);
    return fs.clock;
  }

makes the error disappear.

I'm not sure why adding prints in the getter somehow fixes the problem. In any case, it looks like a web compiler issue.

---

My current theory is that this is caused by overrides in RootNode (either fs or clock).
Maybe there are edge-cases in the web compiler causing this.

To test that assumption, I edited the source of package:file to make it so that RootNode neither overrides this.fs nor this.clock, and the code seems to correctly work now.

The core of the fix is:

abstract class RealNode extends Node {
  /// Constructs a new [RealNode] as a child of the specified [parent].
-  RealNode(DirectoryNode? parent) : super(parent) {
+  RealNode(DirectoryNode? parent, {required this.clock}) : super(parent) {
    int now = clock.now.millisecondsSinceEpoch;
    changed = now;
    modified = now;
    accessed = now;
  }

  /// See [NodeBasedFileSystem.clock].
-  Clock get clock => parent.clock;
+  final Clock clock;

(with changes in DIrectoryNode & co to respect those changes).
That seems to make the error disappear.

I wasn't able to separately reproduce what appears to be a compiler issue outside of package:file unfortunately.

[dnfield]

Seems like a compiler bug.

[rrousselGit]

Indeed.

I opened a compiler issue too dart-lang/sdk#52170