tools.with

This module provides helpers to temporarily install a Ward process middleware and then automatically restore the previous middleware stack.

The most common use-case is running commands through a prefix command (e.g. sudo / doas) without permanently affecting subsequent commands.

w.with(middleware, fn, ...) -> ...

Runs fn(...) while middleware is installed.

local process = require("ward.process")
local w = require("wardlib.tools.with")

w.with(w.middleware.sudo(), function()
  process.cmd("id"):run()
  process.cmd("ls", "-la"):run()
end)

w.with(prefix, fn, ...) -> ...

Convenience form: builds a prefix middleware and runs fn(...) under it.

local w = require("wardlib.tools.with")

w.with({"sudo", "-n"}, function()
  require("ward.process").cmd("whoami"):run()
end)

w.with(prefix_or_mw, cmd) -> cmd_proxy

Wraps a cmd-like object, returning a proxy where any method call runs under the given prefix/middleware.

This provides a compact syntax:

local process = require("ward.process")
local w = require("wardlib.tools.with")

local ls = w.with(process.cmd("sudo"), process.cmd("ls", "-la"))
ls:run()

If your local Ward cmd(...) object doesn’t expose argv via .argv / .spec.argv / ._spec.argv, pass an argv array instead:

local ls = w.with({"sudo", "-n"}, process.cmd("ls", "-la"))
ls:run()

w.middleware.prefix(prefix, opts)

Creates a middleware that prefixes spec.argv (or another field) with prefix.

Options:

• sep (string|nil): insert a separator token between prefix and argv (often "--").
• field (string): which spec field to mutate (default "argv").

local w = require("wardlib.tools.with")

local mw = w.middleware.prefix({"sudo", "-n"}, { sep = "--" })

w.middleware.sudo(opts) / w.middleware.doas(opts)

Convenience constructors.

local w = require("wardlib.tools.with")

w.with(w.middleware.sudo({ preserve_env = true }), function()
  require("ward.process").cmd("env"):run()
end)