Async & Browser JS / Fetch
fetch & JSON
Requesting data over the network, promise-based from start to finish.
`fetch()` returns a promise that resolves once the response headers arrive - not once the full body is downloaded. Reading the body (as JSON, text, etc.) is a second, separate asynchronous step via `response.json()`, which also returns a promise. Both steps are usually awaited in sequence.
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Why?
fetch resolves as soon as headers/status are known - the body might still be streaming in, which is exactly why reading it with .json() is its own separate await.