feat(exrc): search in parent directories (#33889)

feat(exrc): search exrc in parent directories

Problem:
`.nvim.lua` is only loaded from current directory, which is not flexible
when working from a subfolder of the project.

Solution:
Also search parent directories for configuration file.

runtime/doc/news.txt

@@ -122,6 +122,7 @@ DEFAULTS
 
 • 'statusline' default is exposed as a statusline expression (previously it
   was implemented as an internal C routine).
+• Project-local configuration ('exrc') is also loaded from parent directories.
 
 DIAGNOSTICS
 

runtime/doc/options.txt

@@ -2412,9 +2412,9 @@ A jump table for the options with a short description can be found at |Q_op|.
 'exrc' 'ex'		boolean	(default off)
 			global
 	Enables project-local configuration. Nvim will execute any .nvim.lua,
-	.nvimrc, or .exrc file found in the |current-directory|, if the file is
+	.nvimrc, or .exrc file found in the |current-directory| and all parent
-	in the |trust| list. Use |:trust| to manage trusted files. See also
+	directories (ordered upwards), if the files are in the |trust| list.
-	|vim.secure.read()|.
+	Use |:trust| to manage trusted files. See also |vim.secure.read()|.
 
 	Compare 'exrc' to |editorconfig|:
 	- 'exrc' can execute any code; editorconfig only specifies settings.

runtime/doc/vim_diff.txt

@@ -209,6 +209,10 @@ nvim.swapfile:
   swapfile is owned by a running Nvim process. Shows |W325| "Ignoring
   swapfile…" message.
 
+nvim.find_exrc:
+- VimEnter: Extend 'exrc' to also search for project-local configuration files
+  in all parent directories.
+
 ==============================================================================
 New Features                                                   *nvim-features*
 

runtime/lua/vim/_defaults.lua

@@ -925,6 +925,29 @@ do
       end
     end
   end
+
+  vim.api.nvim_create_autocmd('VimEnter', {
+    group = vim.api.nvim_create_augroup('nvim.find_exrc', {}),
+    desc = 'Find project-local configuration',
+    callback = function()
+      if vim.o.exrc then
+        local files = vim.fs.find(
+          { '.nvim.lua', '.nvimrc', '.exrc' },
+          { type = 'file', upward = true, limit = math.huge }
+        )
+        for _, file in ipairs(files) do
+          local trusted = vim.secure.read(file) --[[@as string|nil]]
+          if trusted then
+            if vim.endswith(file, '.lua') then
+              loadstring(trusted)()
+            else
+              vim.api.nvim_exec2(trusted, {})
+            end
+          end
+        end
+      end
+    end,
+  })
 end
 
 --- Default options

runtime/lua/vim/_meta/options.lua

@@ -2076,9 +2076,9 @@ vim.bo.expandtab = vim.o.expandtab
 vim.bo.et = vim.bo.expandtab
 
 --- Enables project-local configuration. Nvim will execute any .nvim.lua,
---- .nvimrc, or .exrc file found in the `current-directory`, if the file is
+--- .nvimrc, or .exrc file found in the `current-directory` and all parent
---- in the `trust` list. Use `:trust` to manage trusted files. See also
+--- directories (ordered upwards), if the files are in the `trust` list.
---- `vim.secure.read()`.
+--- Use `:trust` to manage trusted files. See also `vim.secure.read()`.
 ---
 --- Compare 'exrc' to `editorconfig`:
 --- - 'exrc' can execute any code; editorconfig only specifies settings.

src/nvim/options.lua

@@ -2745,9 +2745,9 @@ local options = {
       defaults = false,
       desc = [=[
         Enables project-local configuration. Nvim will execute any .nvim.lua,
-        .nvimrc, or .exrc file found in the |current-directory|, if the file is
+        .nvimrc, or .exrc file found in the |current-directory| and all parent
-        in the |trust| list. Use |:trust| to manage trusted files. See also
+        directories (ordered upwards), if the files are in the |trust| list.
-        |vim.secure.read()|.
+        Use |:trust| to manage trusted files. See also |vim.secure.read()|.
 
         Compare 'exrc' to |editorconfig|:
         - 'exrc' can execute any code; editorconfig only specifies settings.
@@ -2765,7 +2765,7 @@ local options = {
       full_name = 'exrc',
       scope = { 'global' },
       secure = true,
-      short_desc = N_('read .nvimrc and .exrc in the current directory'),
+      short_desc = N_('read project-local configuration in parent directories'),
       tags = { 'project-config', 'workspace-config' },
       type = 'boolean',
       varname = 'p_exrc',

test/functional/core/startup_spec.lua

@@ -1108,6 +1108,7 @@ describe('user config init', function()
           string.format(
             [[
           vim.g.exrc_file = "%s"
+          vim.g.exrc_count = (vim.g.exrc_count or 0) + 1
         ]],
             exrc_path
           )
@@ -1118,6 +1119,7 @@ describe('user config init', function()
           string.format(
             [[
           let g:exrc_file = "%s"
+          let g:exrc_count = get(g:, 'exrc_count', 0) + 1
         ]],
             exrc_path
           )
@@ -1141,8 +1143,8 @@ describe('user config init', function()
       rmdir(xstate)
     end)
 
-    for _, filename in ipairs({ '.exrc', '.nvimrc', '.nvim.lua' }) do
+    for _, filename in ipairs({ '.exrc', '.nvimrc', '.nvim.lua', '../.nvim.lua', '../.nvimrc' }) do
-      it(filename .. ' in cwd', function()
+      it(filename .. ' from cwd', function()
         setup_exrc_file(filename)
 
         clear { args_rm = { '-u' }, env = xstateenv }
@@ -1185,6 +1187,36 @@ describe('user config init', function()
         eq(filename, eval('g:exrc_file'))
       end)
     end
+
+    it('exrc from all parent directories', function()
+      -- make sure that there are not any exrc files left from previous tests
+      for _, file in ipairs({ '.exrc', '.nvimrc', '.nvim.lua', '../.nvim.lua', '../.nvimrc' }) do
+        os.remove(file)
+      end
+      setup_exrc_file('../.exrc')
+      setup_exrc_file('.nvim.lua')
+      clear { args_rm = { '-u' }, env = xstateenv }
+      local screen = Screen.new(50, 8)
+      screen._default_attr_ids = nil
+      fn.jobstart({ nvim_prog }, {
+        term = true,
+        env = {
+          VIMRUNTIME = os.getenv('VIMRUNTIME'),
+        },
+      })
+      -- current directory exrc is found first
+      screen:expect({ any = '.nvim.lua' })
+      screen:expect({ any = pesc('[i]gnore, (v)iew, (d)eny, (a)llow:') })
+      feed('ia')
+
+      -- after that the exrc in the parent directory
+      screen:expect({ any = '.exrc' })
+      screen:expect({ any = pesc('[i]gnore, (v)iew, (d)eny, (a)llow:') })
+      feed('ia')
+      clear { args_rm = { '-u' }, env = xstateenv }
+      -- a total of 2 exrc files are executed
+      eq(2, eval('g:exrc_count'))
+    end)
   end)
 
   describe('with explicitly provided config', function()