dillon1000/react

[Flight] Tailor the warning for binary data with a toJSON (Node Buffer) (#36873)

A Node.js `Buffer` carries a `toJSON` method, so Flight serializes it
through that method instead of as binary, and it is deserialized as a
plain `{type: 'Buffer', data: [...]}` object rather than a `Buffer` or
`Uint8Array`. The warning React emits in this case reads "Uint8Array
objects are not supported", which is misleading on two counts: the value
is actually a `Buffer`, reported as `Uint8Array` only because that is
its `Object.prototype.toString` tag, and a real `Uint8Array` is in fact
supported, since it has no `toJSON` and serializes as binary. This makes
the message especially confusing when binary data such as a font is
passed as a serialized value.

The first commit adds a test that pins down the current behavior,
capturing both the misleading warning and the deserialization to a plain
`{type: 'Buffer', data: [...]}` object. The second commit replaces the
warning, for values that are `ArrayBuffer.isView`, with one that names
the actual cause and the fix: the data is serialized through `toJSON`
instead of as binary, so a `Uint8Array` or `ArrayBuffer` should be
passed to send binary data. The new branch only fires for a typed array
that also carries a `toJSON`, which in practice is a Node `Buffer`; a
plain `Uint8Array` or `ArrayBuffer` has no `toJSON`, never reaches this
branch, and continues to serialize as binary.