# `Mutare.Phoenix.Download`
[🔗](https://github.com/foxbenjaminfox/mutare_phoenix/blob/v0.3.1/lib/mutare/phoenix/download.ex#L1)

`:download_disposition` — flips the explicit `:disposition` option of
`Phoenix.Controller.send_download/3` between `:attachment` and `:inline`. A surviving
mutant means no test checks whether the response specifies *saving* or *displaying*
the file — the type in the `content-disposition` header.

    send_download(conn, {:file, path}, disposition: :attachment)   # → :inline
    conn |> send_download({:binary, csv}, filename: "r.csv", disposition: :inline)
    #                                                                     ↳ :attachment

Only an explicit literal atom is flipped: a `send_download` that relies on Phoenix's
default (`:attachment`), or passes a variable, is left alone — as is `send_download/2`,
which has no options at all. Matches the call written directly
(`Phoenix.Controller.send_download(conn, ...)`), aliased, or bare-imported
(`send_download(conn, ...)`, the form `use MyAppWeb, :controller` produces).

The swap substitutes exactly the disposition atom, so `Mutare.Transform.Overlap` prunes
the built-in `:atom` family's `:mutare` leaf at that range — which would only crash
(Phoenix rejects any disposition other than `:attachment` / `:inline`), an uninformative
kill.

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*Consult [api-reference.md](api-reference.md) for complete listing*