fecim-fyne-thread-check

name	fecim-fyne-thread-check
description	Audits Go code for goroutine-to-widget access without fyne.Do(...) wrapping, the project's most common GUI freeze cause. Use when reviewing a PR that adds goroutines, async I/O, or simulation tickers in any pkg/gui/ or shell package.

fecim-fyne-thread-check

Find places where a goroutine touches a Fyne widget without fyne.Do(...) wrapping. See tools/fecim-skills/_shared/fecim-context.md (UI thread-safety rule).

Workflow

1. Run the automated guardrail first. It scans default Fyne GUI scopes and exits non-zero on direct mutation-like widget calls inside goroutine literals without fyne.Do/fyne.DoAndWait:

   make fyne-thread-check
   # or scoped:
   go run ./tools/fyne-thread-check module6-eda/pkg/gui/tabs/builder_validation_tab.go
   

2. Define audit scope. Default: module*/pkg/gui/, cmd/fecim-lattice-tools/. Narrow to changed files for PR review:

   git diff --name-only main...HEAD | grep '\.go$' | grep -E 'pkg/gui|cmd/fecim'
   

   Use rg if available; on this host it may be missing, so grep is the default-safe fallback.

3. Find goroutine launches:

   rg -nU 'go func\(' <scope> 2>/dev/null || grep -RIn 'go func(' <scope>
   

4. For each match, examine the body for direct mutation of:

   • *widget.* (e.g., Label.SetText, Button.SetText, Entry.SetText, ProgressBar.SetValue)
   • *canvas.* (e.g., canvas.Refresh, *canvas.Image.Image = ...)
   • *container.* (Add, Remove, Refresh)
   • Direct field assignment to any fyne.CanvasObject

5. Verify the call is wrapped:

   • GOOD: fyne.Do(func() { label.SetText("done") })
   • GOOD: helper function whose body is itself wrapped
   • BAD: bare label.SetText(...) inside go func()

6. Output a violation list:

   <file>:<line>: <symbol>.<method>(...) inside goroutine — needs fyne.Do
     Suggested:
       fyne.Do(func() { <symbol>.<method>(...) })
   

7. Cross-reference docs/3-develop/gui/FYNE_NOTES.md#threading-critical for nuanced cases (animation tickers, blocking dialogs).

Verification

• Input: PR adds go func() { mylabel.SetText("done") }() in module1-hysteresis/pkg/gui/simulation.go. Expected: skill flags simulation.go:<line>: mylabel.SetText and suggests the wrap.

TDD

Audit is observation — TDD: N/A. Any code change made to fix a violation triggers the project's TDD hard-rule.