feat(plugin): add hot-reload support for plugin configs

lua/core/commands.lua

@@ -1,3 +1,23 @@
 vim.api.nvim_create_user_command("W", "w", { desc = "Alias to :w" })
 vim.api.nvim_create_user_command("Q", "q", { desc = "Alias to :q" })
 vim.api.nvim_create_user_command("Qa", "q", { desc = "Alias to :qa" })
+
+vim.api.nvim_create_user_command("PluginWatch", function()
+    require("plugin").watch()
+end, { desc = "Watch plugin configs for changes and hot-reload" })
+
+vim.api.nvim_create_user_command("PluginUnwatch", function()
+    require("plugin").unwatch()
+end, { desc = "Stop watching plugin configs" })
+
+vim.api.nvim_create_user_command("PluginReload", function(opts)
+    require("plugin").reload(opts.args)
+end, {
+    nargs = 1,
+    complete = function(lead)
+        return vim.tbl_filter(function(name)
+            return name:find(lead, 1, true) == 1
+        end, require("plugin").get_names())
+    end,
+    desc = "Reload a plugin config by name",
+})

lua/plugin.lua

@@ -13,6 +13,23 @@ local log = require("log")
 ---@type ow.Plugin[]
 local plugins = {}
 
+---@param path string
+---@return boolean success
+---@return string? err
+local function exec(path)
+    local chunk, load_err = loadfile(path)
+    if not chunk then
+        return false, load_err
+    end
+
+    local ok, call_err = pcall(chunk)
+    if not ok then
+        return false, call_err
+    end
+
+    return true
+end
+
 ---@param plugin ow.Plugin
 local function load(plugin)
     vim.cmd.packadd(plugin.name)
@@ -25,7 +42,7 @@ local function load(plugin)
     )
 
     if vim.uv.fs_stat(path) then
-        local ok, err = pcall(dofile, path)
+        local ok, err = exec(path)
         if not ok then
             log.error("Failed to load %s: %s", name, err)
         end
@@ -97,6 +114,9 @@ local function handle_pack_events(plugin, events)
     return true
 end
 
+---@type uv.uv_fs_event_t?
+local watcher = nil
+
 local M = {}
 
 function M.get_paths()
@@ -109,6 +129,115 @@ function M.get_paths()
     return paths
 end
 
+---@return string[]
+function M.get_names()
+    local names = {}
+
+    for _, plugin in ipairs(plugins) do
+        table.insert(names, plugin.name:match("[^.]+"):lower())
+    end
+
+    return names
+end
+
+---@param name string
+function M.reload(name)
+    local path = string.format(
+        "%s/lua/plugins/%s.lua",
+        vim.fn.stdpath("config"),
+        name
+    )
+
+    if not vim.uv.fs_stat(path) then
+        log.error("No config file found for %s", name)
+        return
+    end
+
+    local ok, err = exec(path)
+    if ok then
+        log.info("Reloaded %s", name)
+    else
+        log.error("Failed to reload %s: %s", name, err)
+    end
+end
+
+function M.watch()
+    if watcher then
+        return
+    end
+
+    local plugins_dir = string.format(
+        "%s/lua/plugins",
+        vim.fn.stdpath("config")
+    )
+
+    watcher = vim.uv.new_fs_event()
+    if not watcher then
+        log.error("Failed to create fs_event watcher")
+        return
+    end
+
+    ---@type table<string, uv.uv_timer_t>
+    local timers = {}
+
+    watcher:start(
+        plugins_dir,
+        {},
+        vim.schedule_wrap(function(err, filename)
+            if err then
+                log.error("Watch error: %s", err)
+                return
+            end
+
+            if not filename or not filename:match("%.lua$") then
+                return
+            end
+
+            if timers[filename] then
+                timers[filename]:stop()
+            else
+                timers[filename] = vim.uv.new_timer()
+            end
+
+            timers[filename]:start(
+                100,
+                0,
+                vim.schedule_wrap(function()
+                    timers[filename]:stop()
+                    timers[filename]:close()
+                    timers[filename] = nil
+
+                    local path = plugins_dir .. "/" .. filename
+                    if not vim.uv.fs_stat(path) then
+                        return
+                    end
+
+                    local ok, load_err = exec(path)
+                    if ok then
+                        log.info("Reloaded %s", filename)
+                    else
+                        log.error(
+                            "Failed to reload %s: %s",
+                            filename,
+                            load_err
+                        )
+                    end
+                end)
+            )
+        end)
+    )
+end
+
+function M.unwatch()
+    if not watcher then
+        return
+    end
+
+    watcher:stop()
+    watcher:close()
+    watcher = nil
+end
+
 ---@param specs (string | ow.Plugin.Spec)[]
 function M.setup(specs)
     ---@type ow.Plugin.PackEvent[]