Custom Mutare mutators for the Phoenix controller surface — the Phoenix.Controller calls a controller action performs on the conn — plus the defensive macro routing that keeps Phoenix's compile-time macros from poisoning the metamutant build.

This package builds on mutare_plug the way phoenix builds on plug: it depends on it, so the Plug.Conn families (Mutare.Plug.all/0) are on your code path too, ready to compose.

Usage

Add mutare_phoenix to your deps, then list the families in .mutare.exs and this module under :extensions. Setting :mutators replaces Mutare's default set, so include the :builtins family to keep the built-ins on:

# .mutare.exs
[
  mutators: [:builtins] ++ Mutare.Plug.all() ++ Mutare.Phoenix.all(),
  extensions: [Mutare.Phoenix]
]

all/0 returns this package's three families:

• Mutare.Phoenix.Redirect — :redirect_status, swaps the explicit atom :status option of Phoenix.Controller.redirect/2 for a redirect-status sibling.
• Mutare.Phoenix.Body — :controller_body, blanks the body of Phoenix.Controller.json/2 (to %{}), text/2, and html/2 (to "").
• Mutare.Phoenix.Download — :download_disposition, flips the explicit :disposition option of Phoenix.Controller.send_download/3 between :attachment and :inline.

It does not include the mutare_plug families; compose Mutare.Plug.all/0 explicitly as shown above. Each family matches its call written directly (Phoenix.Controller.redirect(conn, ...)), aliased, or bare-imported (redirect(conn, ...), the form use MyAppWeb, :controller produces).

The :extensions entry

This module is also a Mutare.CallRouting extension. Listed under :extensions, it routes Phoenix's compile-time-only macro calls :skip — the whole call is an inert leaf, so Mutare neither descends into their arguments nor rewrites the calls themselves:

• the Phoenix.Router DSL (get/post/scope/…), because route definitions run once at compile time under Mutare's compile-once model — a mutation there could never activate;
• Phoenix.Component.sigil_H/2 (~H), because HEEx sigil arguments must remain compile-time literals — left unregistered, Mutare's imported-call witness would splice an unreachable sigil_H(arg1, arg2) that Phoenix rejects at compile time, sinking the whole metamutant build before poison recovery can isolate a single mutant.

Mutations around a ~H expression (for example a render/1 :return_value mutant) remain available; only the sigil's own arguments are opaque.