fix(examples): surface errors from useAsyncCallback in examples/base

[Copilot]

Affected Package(s)

• Examples

Related Issue(s)

Motivation

useAsyncCallback in examples/base had no error handling: a rejected callback left the UI permanently stuck in a loading state with no feedback and the error silently swallowed.

Description of Changes

• useAsyncCallback hook: Added catch (err) block to capture errors from async callbacks. Replaced two separate useState calls (isLoading and error) with a single AsyncCallbackState object ({ isLoading: boolean; error: unknown }), so that starting a new invocation atomically sets isLoading: true and resets error: null in a single render pass. Return type changed from [T, boolean] to [(...args: Parameters<T>) => Promise<unknown>, boolean, unknown], removing the unsafe as T cast and using Parameters<T> to preserve argument types without a type assertion. Control flow restructured so the success path explicitly calls setState before returning the result, and the catch path calls setState and falls off naturally — eliminating previously unreachable code.
• Content component: Destructures the third element (loginError, refreshError, logoutError) and renders them conditionally with safe message extraction and role="alert" for screen reader accessibility:

{loginError != null
  ? <p role="alert">Login error: {loginError instanceof Error ? loginError.message : 'An error occurred'}</p>
  : null}

Breaking Changes

None

How to Test

1. CI Checks: Verify that all automated tests (Vitest) and build steps pass successfully on this PR.
2. Local Verification (Optional):
   • cd examples/base && npm install && npm run dev
   • Wire up an AuthClient whose onLogin rejects — confirm the error message renders and the button is re-enabled immediately.

Checklist

• My code follows the project's style guidelines
• I have added or updated tests to cover the changes
• I have updated relevant documentation
• All tests are passing locally
• CI checks are passing
• I have reviewed my own code and lock file changes
• I have checked for any potential security implications
• I have verified the changes work as expected
• My commit messages follow Conventional Commits format

Notes for Reviewers

No tests added — examples/ has no test infrastructure and is documentation/demo only. The fix is a self-contained change to a single file with no impact on published packages.

[Copilot]

Pull request overview

This PR improves the examples/base demo UX by surfacing async action failures (login/refresh/logout) instead of leaving errors silent, and by exposing that error state from the local useAsyncCallback hook.

Changes:

• Extend the local useAsyncCallback hook to track/reset an error state and return it as a third tuple element.
• Update the Content component to destructure and conditionally render loginError, refreshError, and logoutError.

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[panz3r]

@copilot please have a look at the review comments and apply fixes that looks most appropriate/correct

[Copilot]

@copilot please have a look at the review comments and apply fixes that looks most appropriate/correct

Done in f2d184d. Applied all three remaining review fixes:

1. role="alert" added to all three error <p> elements for screen reader accessibility.
2. Type safety: replaced useCallback(...) as T with (...argsx: Parameters<T>) and an explicit return type of [(...args: Parameters<T>) => Promise<unknown>, boolean, unknown] — no more unsafe cast.
3. Unreachable setState: the old structure had setState({ isLoading: false, error: null }) after a try/catch where both branches returned, making it dead code. Restructured so success explicitly calls setState then returns the result, and the catch sets state and falls off naturally.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

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