Software DevelopmentBeginner 1 to 2 hours

Fix a Bug in a Sample To-Do App

Diagnose and fix a state management bug in a React to-do app.

The Scenario

A small React to-do app has a bug: when a user deletes a task, the wrong task is sometimes removed. The root cause is that list items use array index as a React key instead of a stable ID. A real junior developer fix would not just swap the key, it would also reason about why this bug appeared.

The Brief

You do not need a real repo to complete this task. Work from the following snippet and write a fixed version plus an explanation.

Deliverables

  • A corrected code snippet (paste as a Markdown code block)
  • A 3 to 5 sentence explanation of the root cause, written so a non-technical stakeholder could follow
  • One additional safeguard (a test, a lint rule, or a code review checklist item) that would prevent a similar bug in future

Submission Guidance

Buggy code: ```jsx {tasks.map((task, index) => ( <li key={index} onClick={() => deleteTask(index)}>{task.title}</li> ))} ``` Assume `deleteTask(id)` exists and takes a task id.

Submit Your Work

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