ux.silent catch swallow

ux.silent-catch-swallow

Rule ID: ux.silent-catch-swallow Severity: ERROR Category: ux Target Standards: Nielsen Heuristic #9: Help Users Recognize, Diagnose, and Recover from Errors, ISO 9241-110 Ergonomics of Human-System Interaction (Error Management), Zero-Trust Error Transparency Guidelines

---

1. Overview & Core Invariant

Detects swallowed catch blocks in event handlers that lack user feedback (toast/alert) or re-throw

Core Invariant:

"Catch blocks in user interaction handlers must provide visible UI feedback ('toast', error state, alert) or re-throw the error."

---

2. Technical Grounding & Engine Realities

When user interaction handlers catch exceptions and only log them to 'console.log' or discard them entirely, the failure is silently swallowed.

The user receives no feedback, falsely assumes their changes were saved, and navigates away, only to discover later that critical data was lost. Surfacing visible feedback (e.g. 'toast.error(...)', 'setError(...)', or banner notifications) guarantees that errors are transparent, allowing users to understand the problem and re-attempt the action.

---

3. Vulnerability & Risk Taxonomy

Risk Vector	Severity	Impact
Silent Data Loss & False Sense of Completion	HIGH	Users believe changes succeeded when they actually failed on the network, leading to unrecoverable data loss.
Lack of Failure Diagnostics	MEDIUM	Users cannot self-diagnose network errors or invalid parameters, resulting in confusion and support tickets.

---

4. Non-Compliant Code Patterns (Bad Examples)

TSX (Catch block silently logging to console without notifying the user):

<button
  onClick={async () => {
    try {
      await api.updateProfile(formData);
    } catch (e) {
      console.error(e); // Pengguna tidak tahu aksinya gagal!
    }
  }}
>
  Simpan Profil
</button>

---

5. Compliant Implementation Patterns (Good Examples)

TSX (Catch block notifying user with a toast error notification):

<button
  onClick={async () => {
    try {
      await api.updateProfile(formData);
    } catch (e) {
      toast.error("Gagal memperbarui profil. Silakan coba lagi.");
    }
  }}
>
  Simpan Profil
</button>

---

6. How to Suppress (Ignore Directives)

If this pattern is required for an intentional exception, suppress the diagnostic using the canonical Charites Rule ID:

<!-- charites:ignore ux.silent-catch-swallow intentional exception -->

// charites:ignore ux.silent-catch-swallow intentional exception

---

7. Configuration Reference (charites.yaml)

rules:
  ux.silent-catch-swallow:
    severity: error # error | warn | info | off

---

8. Architectural Domain & Verification Reference

• Domain Architecture & Analysis Pipeline: See the ux Category Guide.
• 1-SSOT Golden Tri-Corpus Test Matrix: See the Verification Harness on the Master Home page.
• Rule Catalog Index: See Master Wiki Home.