Debugging a script

local function note(context, key, value)
    context:set_variable("debug." .. key, value)
end

return {
    on_event_player_trigger = function(context, state, event)
        note(context, "last_trigger", event.slot and event.slot.name or "unknown")
        note(context, "trigger_count", (state:variable("debug.trigger_count") or 0) + 1)
    end,
}

note(context, "slot_index", event.slot_index or -1)
note(context, "registry_key", event.registry_key or -1)

-- Offline check for one mission script. Run it from the Sunrise folder:
--   lua54 check_script.lua my_mission
local name = assert(arg and arg[1], "usage: lua54 check_script.lua <script name>")
package.path = "sdk/lua/?.lua;scripts/?.lua"

local out, open_file = print, loadfile
local calls = {}

-- A fake handle: listed fields answer; any other key is a method that records its call.
local function fake(label, fields)
    return setmetatable(fields or {}, {__index = function(_, key)
        return function()
            calls[#calls + 1] = label .. ":" .. key
            return fake(label .. ":" .. key, {value = tostring(#calls)})
        end
    end})
end

local sdk = fake("sdk", {
    device_transitions = {open = "open", close = "close", power_on = "power_on",
        power_off = "power_off", lock = "lock", unlock = "unlock"},
    device_channels = {position = "position", power = "power", lock = "lock"},
    squad_modes = {reinforce = "reinforce", replace = "replace", reserve = "reserve"},
    atom_kinds = {face = "face", sequence = "sequence", sleep = "sleep", move_to = "move_to",
        trivial = "trivial", control_flag = "control_flag", snap_to = "snap_to",
        set_temperament = "set_temperament", set_channel = "set_channel", ability = "ability"},
    client_teleport_reset = 0,
    unit = function(x) return x end,
})

local variables = {}
local function selector(kind)
    return function(_, id)
        assert(type(id) == "string" or math.type(id) == "integer", kind .. " selector is invalid")
        return fake(kind .. " " .. tostring(id), {id = id})
    end
end

local context = fake("context", {
    sdk = sdk,
    attempt_generation = "1",
    activity_role = "private",
    player_key = "1",
    mission_complete = false,
    slot = selector("slot"),
    squad = selector("squad"),
    scene = selector("scene"),
    cohort = function() return {cleared = false, observed_full = false, size = 1} end,
    set_variable = function(_, key, value) variables[key] = value end,
    clear_variable = function(_, key)
        local had = variables[key] ~= nil
        variables[key] = nil
        return had
    end,
    start_timer = function() return "1" end,
    cancel_timer = function() return false end,
    set_phase = function() end,
})

local state = {
    phase = 0,
    revision = "0",
    variable = function(_, key) return variables[key] end,
    has_variable = function(_, key) return variables[key] ~= nil end,
    timer = function() return nil end,
}

-- Remove what the runtime sandbox removes, so the script cannot use it here either.
for _, key in ipairs({"collectgarbage", "dofile", "getmetatable", "load", "loadfile", "next",
    "pairs", "print", "rawequal", "rawlen", "warn", "xpcall"}) do
    _G[key] = nil
end
for _, key in ipairs({"dump", "find", "match", "gmatch", "gsub"}) do
    string[key] = nil
end
math.random, math.randomseed = nil, nil

local chunk = assert(open_file("scripts/" .. name .. "/" .. name .. ".lua", "t"))
local program = chunk()
assert(type(program) == "table", "the script must return a table")
if program.on_start ~= nil then
    program.on_start(context, state)
end

out("requests made by on_start:")
for _, call in ipairs(calls) do
    out("  " .. call)
end

local event = {kind = 40, region_index = 16, attempt_generation = "1"}
program.on_event_region_changed(context, state, event)