Plugin-Hot-Reload

-- The one line at the top of every plugin file:
--
--     if (HR and HR()) then return end
--
-- When the engine refreshes a single plugin file, this hands the reload to my
-- loader and stops the stale copy from running on its own.

local function hotreloadPlugins()
    if (HR_HOTRELOADING) then return end
    HR_HOTRELOADING = true

    hr.plugin.loadFromDir("plugins-hr")   -- mirrors the framework's own loader (omitted)

    -- Rebuilding the spawn menu was the main lag source, so it's suppressed during reloads.
    hook.Add("SpawnMenuEnabled", "hotreload-lagfix", function() return false end)

    -- Replay the framework's start-up events, skipping plugins on the
    -- opt-out list that can't handle running them twice.
    local skipped = {}
    for uniqueID in pairs(skipInitializedPlugins) do
        local plugin = nut.plugin.list[uniqueID]
        local fn = hook.GetTable()["InitializedPlugins"][plugin]
        if (fn) then
            hook.Remove("InitializedPlugins", plugin)
            skipped[plugin] = fn
        end
    end
    hook.Run("InitializedPlugins")
    for plugin, fn in pairs(skipped) do
        hook.Add("InitializedPlugins", plugin, fn)
    end

    hook.Remove("SpawnMenuEnabled", "hotreload-lagfix")
    hook.Run("InitializedItems")

    HR_HOTRELOADING = nil
end

function HR()
    -- Only plugins from the hot-reload folder are handled.
    local src = debug.getinfo(2, "S").source
    if (src and not string.find(src, "hotreload%-plugins")) then return end

    -- Re-entrancy: never start a reload while one is running, while the loader
    -- is including plugin files itself, or right after a full gamemode reload.
    if (HR_HOTRELOADING) then return end
    if (HR_PLUGIN_LOADING or HR_PLUGINS_ALREADY_LOADED) then return end

    hotreloadPlugins()
    return true
end

-- A full gamemode reload loads the plugins once, then blocks the per-file
-- guard for a second so every plugin file doesn't trigger its own reload.
hook.Add("OnReloaded", "hotreload-gm-reload", function()
    if (HR_PLUGINS_ALREADY_LOADED) then return end
    timer.Simple(0, hotreloadPlugins)
    HR_PLUGINS_ALREADY_LOADED = true
    timer.Create("hotreload-gm-reload", 1, 1, function()
        HR_PLUGINS_ALREADY_LOADED = false
    end)
end)