The FormData API: From HTML Forms to Typed Objects
FormData serializes an HTML form into key/value pairs for `fetch`. In TypeScript, its main footgun is that `get()` returns a generic `string | File | null`, requiring you to validate and cast the data before using it safely.
The FormData API is a browser standard for serializing an HTML form into key/value pairs, perfect for sending with `fetch`. It's like a digital envelope for form data, handling file uploads and `multipart/form-data` encoding automatically. The main footgun in TypeScript is that FormData is not type-safe by default. `formData.get('field')` returns `string | File | null`, so you must always validate and cast values before using them in your typed application logic.
Read the original → developer.mozilla.org
- #typescript
- #web-api
- #forms
- #fetch
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