refactor(checkhealth)!: rename to vim.health, move logic to Lua #18720

- Complete function:
  There was lots of unnecessary C code for the complete function, therefore
  moving it to Lua and use all the plumbing we have in place to retrieve the
  results.
- Moving the module:
  It's important we keep nvim lua modules name spaced, avoids conflict with
  plugins, luarocks, etc.

8 files changed, 90 insertions, 117 deletions

diff --git a/runtime/doc/pi_health.txt b/runtime/doc/pi_health.txt
index 179c1066cd..04e04b5165 100644
--- a/runtime/doc/pi_health.txt
+++ b/runtime/doc/pi_health.txt
@@ -48,27 +48,26 @@ Commands                                *health-commands*
                         :checkhealth vim*
 <
 ==============================================================================
-Lua Functions                           *health-functions-lua* *health-lua*
+Lua Functions                       *health-functions-lua* *health-lua* *vim.health*
 
 The Lua "health" module can be used to create new healthchecks (see also
-|health-functions-vim|). To get started, simply use:  >
-        local health = require('health')
-<
-health.report_start({name})                             *health.report_start()*
+|health-functions-vim|). To get started, simply use:
+
+vim.health.report_start({name})                         *vim.health.report_start()*
         Starts a new report. Most plugins should call this only once, but if
         you want different sections to appear in your report, call this once
         per section.
 
-health.report_info({msg})                               *health.report_info()*
+vim.health.report_info({msg})                           *vim.health.report_info()*
         Reports an informational message.
 
-health.report_ok({msg})                                 *health.report_ok()*
+vim.health.report_ok({msg})                             *vim.health.report_ok()*
         Reports a "success" message.
 
-health.report_warn({msg} [, {advice}])                  *health.report_warn()*
+vim.health.report_warn({msg} [, {advice}])              *vim.health.report_warn()*
         Reports a warning. {advice} is an optional List of suggestions.
 
-health.report_error({msg} [, {advice}])                 *health.report_error()*
+vim.health.report_error({msg} [, {advice}])             *vim.health.report_error()*
         Reports an error. {advice} is an optional List of suggestions.
 
 ==============================================================================
@@ -98,15 +97,14 @@ Copy this sample code into `lua/foo/health/init.lua` or `lua/foo/health.lua`,
 replacing "foo" in the path with your plugin name: >
 
         local M = {}
-        local health = require("health")
 
         M.check = function()
-          health.report_start("my_plugin report")
+          vim.health.report_start("my_plugin report")
           -- make sure setup function parameters are ok
           if check_setup() then
-            health.report_ok("Setup function is correct")
+            vim.health.report_ok("Setup function is correct")
           else
-            health.report_error("Setup function is incorrect")
+            vim.health.report_error("Setup function is incorrect")
           end
           -- do some more checking
           -- ...
diff --git a/runtime/lua/health.lua b/runtime/lua/health.lua
index 142a353bf2..40e2b3c3e7 100644
--- a/runtime/lua/health.lua
+++ b/runtime/lua/health.lua
@@ -1,23 +1,6 @@
-local M = {}
-
-function M.report_start(msg)
-  vim.fn['health#report_start'](msg)
-end
-
-function M.report_info(msg)
-  vim.fn['health#report_info'](msg)
-end
-
-function M.report_ok(msg)
-  vim.fn['health#report_ok'](msg)
-end
-
-function M.report_warn(msg, ...)
-  vim.fn['health#report_warn'](msg, ...)
-end
-
-function M.report_error(msg, ...)
-  vim.fn['health#report_error'](msg, ...)
-end
-
-return M
+return setmetatable({}, {
+  __index = function(_, k)
+    vim.deprecate("require('health')", 'vim.health', '0.9', false)
+    return vim.health[k]
+  end,
+})
diff --git a/runtime/lua/vim/_editor.lua b/runtime/lua/vim/_editor.lua
index e6ab48f30d..c8a0aa8260 100644
--- a/runtime/lua/vim/_editor.lua
+++ b/runtime/lua/vim/_editor.lua
@@ -49,6 +49,7 @@ for k, v in pairs({
   diagnostic = true,
   keymap = true,
   ui = true,
+  health = true,
 }) do
   vim._submodules[k] = v
 end
diff --git a/runtime/lua/vim/health.lua b/runtime/lua/vim/health.lua
new file mode 100644
index 0000000000..67c5c3b37f
--- /dev/null
+++ b/runtime/lua/vim/health.lua
@@ -0,0 +1,47 @@
+local M = {}
+
+function M.report_start(msg)
+  vim.fn['health#report_start'](msg)
+end
+
+function M.report_info(msg)
+  vim.fn['health#report_info'](msg)
+end
+
+function M.report_ok(msg)
+  vim.fn['health#report_ok'](msg)
+end
+
+function M.report_warn(msg, ...)
+  vim.fn['health#report_warn'](msg, ...)
+end
+
+function M.report_error(msg, ...)
+  vim.fn['health#report_error'](msg, ...)
+end
+
+local path2name = function(path)
+  if path:match('%.lua$') then
+    -- Lua: transform "../lua/vim/lsp/health.lua" into "vim.lsp"
+    return path:gsub('.-lua[%\\%/]', '', 1):gsub('[%\\%/]', '.'):gsub('%.health.-$', '')
+  else
+    -- Vim: transform "../autoload/health/provider.vim" into "provider"
+    return vim.fn.fnamemodify(path, ':t:r')
+  end
+end
+
+local PATTERNS = { '/autoload/health/*.vim', '/lua/**/**/health.lua', '/lua/**/**/health/init.lua' }
+-- :checkhealth completion function used by ex_getln.c get_healthcheck_names()
+M._complete = function()
+  local names = vim.tbl_flatten(vim.tbl_map(function(pattern)
+    return vim.tbl_map(path2name, vim.api.nvim_get_runtime_file(pattern, true))
+  end, PATTERNS))
+  -- Remove duplicates
+  local unique = {}
+  vim.tbl_map(function(f)
+    unique[f] = true
+  end, names)
+  return vim.tbl_keys(unique)
+end
+
+return M
diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index a94d6edce2..5f12826a0c 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -233,23 +233,6 @@ static int compl_match_arraysize;
 static int compl_startcol;
 static int compl_selected;
 
-/// |:checkhealth| completion items
-///
-/// Regenerates on every new command line prompt, to accommodate changes on the
-/// runtime files.
-typedef struct {
-  garray_T names;  // healthcheck names
-  unsigned last_gen;  // last_prompt_id where names were generated
-} CheckhealthComp;
-
-/// Cookie used when converting filepath to name
-struct healthchecks_cookie {
-  garray_T *names;  // global healthchecks
-  bool is_lua;  // true if the current entry is a Lua healthcheck
-};
-
-static CheckhealthComp healthchecks = { GA_INIT(sizeof(char_u *), 10), 0 };
-
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "ex_getln.c.generated.h"
 #endif
@@ -301,59 +284,23 @@ static void init_incsearch_state(incsearch_state_T *s)
 /// @param[in] xp  Not used.
 static char *get_healthcheck_names(expand_T *xp, int idx)
 {
-  // Generate the first time or on new prompt.
-  if (healthchecks.last_gen == 0 || healthchecks.last_gen != last_prompt_id) {
-    ga_clear_strings(&healthchecks.names);
-    char *patterns[3] = { "autoload/health/**.vim", "lua/**/**/health/init.lua",  // NOLINT
-                          "lua/**/**/health.lua" };  // NOLINT
-    for (int i = 0; i < 3; i++) {
-      struct healthchecks_cookie hcookie = { .names = &healthchecks.names, .is_lua = i != 0 };
-      do_in_runtimepath(patterns[i], DIP_ALL, get_healthcheck_cb, &hcookie);
-
-      if (healthchecks.names.ga_len > 0) {
-        ga_remove_duplicate_strings(&healthchecks.names);
-      }
-    }
-    // Tracked to regenerate items on next prompt.
-    healthchecks.last_gen = last_prompt_id;
-  }
-  return idx < healthchecks.names.ga_len
-    ? ((char **)(healthchecks.names.ga_data))[idx] : NULL;
-}
-
-/// Transform healthcheck file path into it's name.
-///
-/// Used as a callback for do_in_runtimepath
-/// @param[in] path  Expanded path to a possible healthcheck.
-/// @param[out] cookie  Array where names will be inserted.
-static void get_healthcheck_cb(char *path, void *cookie)
-{
-  if (path != NULL) {
-    struct healthchecks_cookie *hcookie = (struct healthchecks_cookie *)cookie;
-    char *pattern;
-    char *sub = "\\1";
-    char *res;
-
-    if (hcookie->is_lua) {
-      // Lua: transform "../lua/vim/lsp/health.lua" into "vim.lsp"
-      pattern = ".*lua[\\/]\\(.\\{-}\\)[\\/]health\\([\\/]init\\)\\?\\.lua$";
-    } else {
-      // Vim: transform "../autoload/health/provider.vim" into "provider"
-      pattern = ".*[\\/]\\([^\\/]*\\)\\.vim$";
-    }
+  static Object names = OBJECT_INIT;
+  static unsigned last_gen = 0;
 
-    res = do_string_sub(path, pattern, sub, NULL, "g");
-    if (hcookie->is_lua && res != NULL) {
-      // Replace slashes with dots as represented by the healthcheck plugin.
-      char *ares = do_string_sub(res, "[\\/]", ".", NULL, "g");
-      xfree(res);
-      res = ares;
-    }
+  if (last_gen != last_prompt_id || last_gen == 0) {
+    Array a = ARRAY_DICT_INIT;
+    Error err = ERROR_INIT;
+    Object res = nlua_exec(STATIC_CSTR_AS_STRING("return vim.health._complete()"), a, &err);
+    api_clear_error(&err);
+    api_free_object(names);
+    names = res;
+    last_gen = last_prompt_id;
+  }
 
-    if (res != NULL) {
-      GA_APPEND(char *, hcookie->names, res);
-    }
+  if (names.type == kObjectTypeArray && idx < (int)names.data.array.size) {
+    return names.data.array.items[idx].data.string.data;
   }
+  return NULL;
 }
 
 // Return true when 'incsearch' highlighting is to be done.
diff --git a/test/functional/fixtures/lua/test_plug/health/init.lua b/test/functional/fixtures/lua/test_plug/health/init.lua
index d07632cff4..58162d4515 100644
--- a/test/functional/fixtures/lua/test_plug/health/init.lua
+++ b/test/functional/fixtures/lua/test_plug/health/init.lua
@@ -1,11 +1,10 @@
 local M = {}
-local health = require("health")
 
 M.check = function()
-  health.report_start("report 1")
-  health.report_ok("everything is fine")
-  health.report_start("report 2")
-  health.report_ok("nothing to see here")
+  vim.health.report_start("report 1")
+  vim.health.report_ok("everything is fine")
+  vim.health.report_start("report 2")
+  vim.health.report_ok("nothing to see here")
 end
 
 return M
diff --git a/test/functional/fixtures/lua/test_plug/submodule/health.lua b/test/functional/fixtures/lua/test_plug/submodule/health.lua
index d07632cff4..58162d4515 100644
--- a/test/functional/fixtures/lua/test_plug/submodule/health.lua
+++ b/test/functional/fixtures/lua/test_plug/submodule/health.lua
@@ -1,11 +1,10 @@
 local M = {}
-local health = require("health")
 
 M.check = function()
-  health.report_start("report 1")
-  health.report_ok("everything is fine")
-  health.report_start("report 2")
-  health.report_ok("nothing to see here")
+  vim.health.report_start("report 1")
+  vim.health.report_ok("everything is fine")
+  vim.health.report_start("report 2")
+  vim.health.report_ok("nothing to see here")
 end
 
 return M
diff --git a/test/functional/fixtures/lua/test_plug/submodule_failed/health.lua b/test/functional/fixtures/lua/test_plug/submodule_failed/health.lua
index 3a8af6ebb2..ee5f4e404b 100644
--- a/test/functional/fixtures/lua/test_plug/submodule_failed/health.lua
+++ b/test/functional/fixtures/lua/test_plug/submodule_failed/health.lua
@@ -1,10 +1,9 @@
 local M = {}
-local health = require("health")
 
 M.check = function()
-  health.report_start("report 1")
-  health.report_ok("everything is fine")
-  health.report_warn("About to add a number to nil")
+  vim.health.report_start("report 1")
+  vim.health.report_ok("everything is fine")
+  vim.health.report_warn("About to add a number to nil")
   local a = nil + 2
   return a
 end