feat(state): harden viewmodel management

crates/dust_driver/tests/driver_tests/pub_workspace.rs

@@ -85,7 +85,7 @@ fn watch_rebuilds_member_package_when_shared_workspace_config_changes() {
         fail_fast: false,
         jobs: None,
         poll_interval_ms: 20,
-        max_cycles: Some(3),
+        max_cycles: Some(50),
     });
     modifier.join().unwrap();
 

crates/dust_driver/tests/driver_tests/state_outputs.rs

@@ -1,4 +1,4 @@
-use std::fs;
+use std::{fs, path::PathBuf};
 
 use dust_driver::{BuildRequest, run_build};
 
@@ -23,9 +23,39 @@ fn build_writes_state_output_for_view_model_library() {
     assert!(output.exists());
     assert!(source.contains("abstract class $TaskBoardViewModel"));
     assert!(source.contains("extends ViewModelBase<TaskBoardState, TaskBoardArgs>"));
-    assert!(!source.contains("enum _TaskBoardViewModelAspect"));
+    assert!(!source.contains("_TaskBoardViewModelAspect"));
     assert!(source.contains("TaskBoardState get value"));
-    assert!(source.contains("R select<R>(R Function(TaskBoardState state) selector)"));
+    assert!(!source.contains("select<R>"));
+    assert!(!source.contains("int get count"));
+    assert!(!source.contains("String? get message"));
+}
+
+#[test]
+fn build_writes_async_state_output_for_view_model_library() {
+    let workspace = make_workspace();
+    write_async_state_workspace(workspace.path());
+
+    let result = run_build(BuildRequest {
+        cwd: workspace.path().to_path_buf(),
+        fail_fast: true,
+        jobs: None,
+        db: Default::default(),
+    });
+    let output = workspace.path().join("lib/profile_view_model.g.dart");
+    let source = fs::read_to_string(&output).unwrap();
+
+    assert!(!result.has_errors(), "{:?}", result.diagnostics);
+    assert!(result.diagnostics.is_empty(), "{:?}", result.diagnostics);
+    assert!(output.exists());
+    assert!(source.contains("abstract class $ProfileViewModel"));
+    assert!(source.contains("extends AsyncViewModelBase<Profile, ProfileArgs>"));
+    assert!(source.contains("AsyncState<Profile> get value"));
+    assert!(source.contains("final R Function(AsyncState<Profile> state) selector"));
+    assert!(source.contains("class ProfileViewModelBuilder extends StatelessWidget"));
+    assert!(source.contains("final Widget Function(BuildContext context, Profile data) data"));
+    assert!(!source.contains("const Profile()"));
+    assert!(!source.contains("initialState:"));
+    assert_state_snapshot("async_profile_view_model.dart.snapshot", &source);
 }
 
 fn write_state_workspace(root: &std::path::Path) {
@@ -49,3 +79,36 @@ fn write_state_workspace(root: &std::path::Path) {
          }\n",
     );
 }
+
+fn write_async_state_workspace(root: &std::path::Path) {
+    write_file(
+        &root.join("lib/profile_view_model.dart"),
+        "import 'package:dust_flutter/state.dart';\n\
+         part 'profile_view_model.g.dart';\n\
+         final class Profile { const Profile(this.name); final String name; }\n\
+         final class ProfileRepository { const ProfileRepository(); }\n\
+         final class ProfileArgs extends ViewModelArgs {\n\
+           const ProfileArgs({required this.repository, super.observer});\n\
+           final ProfileRepository repository;\n\
+         }\n\
+         @ViewModel(state: Profile, args: ProfileArgs, mode: ViewModelMode.async)\n\
+         final class ProfileViewModel extends $ProfileViewModel {\n\
+           ProfileViewModel(super.args);\n\
+           @override\n\
+           Future<Profile> loadData() async => const Profile('Ada');\n\
+         }\n",
+    );
+}
+
+fn assert_state_snapshot(name: &str, actual: &str) {
+    let path = state_snapshot_path(name);
+    let expected = fs::read_to_string(&path)
+        .unwrap_or_else(|error| panic!("missing state snapshot `{}`: {error}", path.display()));
+    assert_eq!(actual, expected, "state snapshot `{name}` changed");
+}
+
+fn state_snapshot_path(name: &str) -> PathBuf {
+    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .join("tests/driver_tests/state_outputs/snapshots")
+        .join(name)
+}