mutare_gettext

A Mutare extension for Gettext macro expansion and argument routing. It produces no mutations of its own. It configures Mutare's built-in mutators to mutate runtime arguments in a use Gettext module while preserving the literals required to compile the metamutant.

Install

# mix.exs
def deps do
  [
    {:mutare, "~> 0.4.1", only: [:dev, :test], runtime: false},
    {:mutare_gettext, "~> 0.2", only: [:dev, :test], runtime: false}
  ]
end

# .mutare.exs
[extensions: [Mutare.Gettext]]

What it does

Gettext (>= 0.26) requires two accommodations for a single-compile mutation tool:

1. use Gettext, backend: MyApp.Gettext registers its backend by mutating the caller module, so Mutare's in-process use expansion raises before recovering the injected import Gettext.Macros — leaving bare gettext/ngettext calls unresolved.
2. A message id (gettext("Hello")) must be a compile-time literal; splicing a mutation selector there causes a macro expansion error and prevents compilation.

The extension fixes both via Mutare's two extension capability behaviours:

• Mutare.UseExpansion (expand_use/3) supplies import Gettext.Macros directly for every use Gettext during Mutare's scan, so the bare calls resolve.
• Mutare.CallRouting (call_routes/0) routes each macro's arguments per position: the compile-time literals (message id, plural id, domain, context, backend) are :raw (left unchanged), while the runtime arguments — the ngettext plural count and the interpolation bindings — are :expression, so mutation testing can check whether tests detect changes to plural counts and interpolation values.

This uses a whole-module :raw baseline plus a per-position override for every arity with a count or bindings argument. The overrides are derived from the Gettext macro families; the test suite cross-checks each one against the Gettext.Macros exports.

Targets Gettext >= 0.26; on older versions the extension has no effect.

Development

mix deps.get
mix test
mix check      # format --check-formatted, credo, dialyzer

License

MIT — see LICENSE.