Add external data and persistence

What you will build

Use a public API as enhancement while keeping core tracking usable on failure.

Understand the idea first

Use a public API as enhancement while keeping core tracking usable on failure.

Build it step by step

try {
  const tip = await loadDailyTip();
  showTip(tip);
} catch {
  showTip('今天先完成一小步。');
}
saveSessions(state.sessions);

1. Open the previous project and record its result.
2. Type the example and complete: Simulate timeout, 500, broken JSON, and offline; adding a record must still work.
3. Change one input, predict, then verify.
4. Create and repair: An enhancement API must not become a single point of failure.

Read the important lines

• Use a public API as enhancement while keeping core tracking usable on failure.
• Read input, processing, and output separately.
• Verify another input and an edge case.

Common mistakes and what to check

Practice without copying

Simulate timeout, 500, broken JSON, and offline; adding a record must still work.

Completion check

• I produced the required visible result
• I can explain the input, processing, and output
• I tested normal, edge, and failure cases