First test run in a session triggers slow discovery of all test suites #5879
Description
Describe the bug
After running a test file with test_reflective_loader, I see all gutter icons just fine, but if I right-click to debug a specific test, I see the Discovering Tests... status for a very long time.
Simply restarting the extension host reproduces it. I don't need to edit anything to see this behaviour (tested on the SDK just now).
To Reproduce
Steps to reproduce the behavior:
- Open a
test_reflective_loadertest file - Run it fully
- Try using the gutter icon to debug a single test
Expected behavior
For it to immediately start the debugger (not needing to discover tests).
Extra
I'll see if I can profile the extension to send some more info here.
Please complete the following information:
Workspace Environment
Dart Code extension: 3.127.20260115
Flutter extension: 3.127.20251229 (activated)
App: Visual Studio Code
App Host: desktop
Version: win 1.108.1
Workspace type: Dart (LSP)
Workspace name: essential_lints
Dart (3.12.0-edge.2bfdb03c4afd1592ca3c35bfa8e87c19a9db0c95): C:\Users\felip_0vh5fa6\dart
Flutter (3.38.6): C:\Users\felip_0vh5fa6\.puro\envs\stable\flutter (No device)
Output from 'dart info'
C:\Users\felip_0vh5fa6\dart\bin\dart.exe info
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General info
- Dart 3.12.0-edge.2bfdb03c4afd1592ca3c35bfa8e87c19a9db0c95 (main) (Sat Jan 17 17:33:05 2026 -0800) on "windows_x64"
- on windows / "Windows 11 Pro" 10.0 (Build 26200)
- locale is pt-BR
Project info
- sdk constraint: '^3.10.0'
- dependencies: analysis_server_plugin, analyzer, essential_lints_annotations, logging, meta
- dev_dependencies: analyzer_testing, frontend_server_client, test, test_reflective_loader, very_good_analysis
Process info
| Memory | CPU | Elapsed time | Command line |
|---|---|---|---|
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dart.exe | |
| 0 MB | -- | dartvm.exe | |
| 0 MB | -- | dartvm.exe |