Google ACE Deploying and Implementing a Cloud Solution Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  response.end(JSON.stringify({ 'status': 'ok' }))

  Why it's wrong here

  The parameter is named 'res' in Cloud Functions' HTTP trigger signature, so 'response' is undefined in this scope. Even if it were defined, calling .end() only writes the raw string without setting the Content-Type header to application/json; the client would receive the correct body but not as encoded JSON. In practice, this code would raise a ReferenceError before sending anything, which is why it is incorrect.

• ✗

  return { 'status': 'ok' }

  Why it's wrong here

  For an HTTP-triggered Cloud Function, returning a plain object from your function does not automatically send it to the client. The function signature provides a response object, and you must explicitly call a method like res.send() or res.json() to write the HTTP response. The returned value is ignored unless it is a Promise that triggers asynchronous work; otherwise, the function ends without completing the request, causing a timeout or a 500 error.

• ✗

  context.done(null, { 'status': 'ok' })

  Why it's wrong here

  The context.done callback is part of the background (event-driven) functions contract, not HTTP triggers. When using an HTTP trigger, the function receives a request and a response object, and you must use res.send(), res.end(), or res.status() to finish the request. If you attempt to call context.done, the context object may be undefined for an HTTP function, and even if it exists, it cannot send a response to the client, so the request remains unresolved.

• ✓

  res.send({ 'status': 'ok' })

  Why this is correct

  res.send({ 'status': 'ok' }) is the correct, recommended way to complete an HTTP-triggered Cloud Function. When passed an object, res.send automatically serializes it to JSON and sets the Content-Type response header to application/json, and it terminates the request. This works because Cloud Functions' HTTP handlers receive an Express-style response object, making this pattern highly reliable and idiomatic.

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