chore: add custom health check capability (#213)

* chore: also count empty string as nil

* chore: add custom health check capabilities

* chore(doc): auto generate docs

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: xiaoshihou514

CUSTOMIZE.md

@@ -25,6 +25,7 @@ A tool is specified as follows:
     -- special
     parse            -- function: linter only, parses linter output to neovim diagnostic
     events           -- { name: string, opt: autocmd options }: override default events, for formatter autocmds only the first one is used (passed in from `:fmt`)
+    health           -- function: called in health checks
 }
 ```
 

doc/guard.nvim.txt

@@ -1,4 +1,4 @@
-*guard.nvim.txt*            For NVIM v0.8.0           Last change: 2025 May 16
+*guard.nvim.txt*           For NVIM v0.8.0           Last change: 2025 June 08
 
 ==============================================================================
 Table of Contents                               *guard.nvim-table-of-contents*
@@ -194,6 +194,7 @@ A tool is specified as follows:
         -- special
         parse            -- function: linter only, parses linter output to neovim diagnostic
         events           -- { name: string, opt: autocmd options }: override default events, for formatter autocmds only the first one is used (passed in from `:fmt`)
+        health           -- function: called in health checks
     }
 <
 

lua/guard/health.lua

@@ -5,28 +5,32 @@ local util = require('guard.util')
 local events = require('guard.events')
 local M = {}
 
+local function check_cmd(conf, checked)
+  if conf.cmd and not vim.tbl_contains(checked, conf.cmd) then
+    if fn.executable(conf.cmd) == 1 then
+      ok(conf.cmd .. ' found')
+    else
+      error(conf.cmd .. ' not found')
+    end
+    table.insert(checked, conf.cmd)
+  end
+end
+
 local function executable_check()
   local checked = {}
   for _, item in pairs(filetype) do
     for _, conf in ipairs(item.formatter or {}) do
-      if conf.cmd and not vim.tbl_contains(checked, conf.cmd) then
-        if fn.executable(conf.cmd) == 1 then
-          ok(conf.cmd .. ' found')
-        else
-          error(conf.cmd .. ' not found')
-        end
-        table.insert(checked, conf.cmd)
+      if conf.health then
+        conf.health()
+      else
+        check_cmd(conf, checked)
       end
     end
-
     for _, conf in ipairs(item.linter or {}) do
-      if conf.cmd and not vim.tbl_contains(checked, conf.cmd) then
-        if fn.executable(conf.cmd) == 1 then
-          ok(conf.cmd .. ' found')
-        else
-          error(conf.cmd .. ' not found')
-        end
-        table.insert(checked, conf.cmd)
+      if conf.health then
+        conf.health()
+      else
+        check_cmd(conf, checked)
       end
     end
   end

lua/guard/util.lua

@@ -165,6 +165,7 @@ function M.toolcopy(c)
     env = c.env,
     timeout = c.timeout,
     parse = c.parse,
+    health = c.health,
   }
 end