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tessl-labs/frontend-error-handling

Proactive error handling for React and vanilla JS frontends — every data-fetching component gets loading, error, and empty states, error boundaries, fetch error handling, form validation, optimistic rollback

90

1.38x
Quality

84%

Does it follow best practices?

Impact

100%

1.38x

Average score across 5 eval scenarios

SecuritybySnyk

Passed

No known issues

Overview
Quality
Evals
Security
Files

Evaluation results

100%

25%

Order History Page

Criteria
Without context
With context

Loading state while fetching orders

100%

100%

Error state with retry for order fetch

50%

100%

Empty state for no orders

100%

100%

Reorder action error handling

100%

100%

Fetch handles network errors

100%

100%

Fetch handles HTTP errors

100%

100%

Error state uses role=alert

0%

100%

User-friendly error messages

100%

100%

Error boundary present

0%

100%

100%

33%

Product Listing Page

Criteria
Without context
With context

Loading state while fetching products

100%

100%

Error state with retry for product fetch

50%

100%

Empty state for no products

0%

100%

Error state uses role=alert

0%

100%

Fetch handles network errors

100%

100%

Fetch handles HTTP errors

100%

100%

Add to cart error handling

100%

100%

User-friendly error messages

100%

100%

Error boundary present

0%

100%

100%

27%

Settings Form

Criteria
Without context
With context

Loading state while fetching settings

100%

100%

Fetch error state with retry

28%

100%

Submitting/saving state shown

100%

100%

Submission error handling

100%

100%

Client-side validation

20%

100%

Error messages use role=alert

60%

100%

Fetch handles HTTP errors

100%

100%

User-friendly error messages

87%

100%

Error boundary present

0%

100%

100%

18%

Team Directory

Criteria
Without context
With context

Loading state while fetching team members

100%

100%

Error state with retry for team fetch

50%

100%

Empty state for no results

100%

100%

Invite form submission error handling

100%

100%

Invite form submitting state

100%

100%

Invite form client-side validation

90%

100%

Fetch handles network and HTTP errors

100%

100%

Error messages use role=alert

0%

100%

User-friendly error messages

100%

100%

100%

35%

User Profile Page

Criteria
Without context
With context

Loading state while fetching profile

100%

100%

Error state with retry for profile

37%

100%

Error state uses role=alert

0%

100%

Fetch handles network errors

100%

100%

Fetch handles HTTP errors

100%

100%

User-friendly error messages

70%

100%

Empty activity state handled

100%

100%

Error boundary present

0%

100%

Evaluated
Agent
Claude Code
Model
Claude Sonnet 4.6

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