feat(vim.fs): pass path to find() predicate, lazy evaluate #22378

Problem:
No easy way to find files under certain directories (ex: grab all files under
`test/`) or exclude the content of certain paths (ex. `build/`, `.git/`)

Solution:
Pass the full `path` as an arg to the predicate.

1 files changed, 29 insertions, 6 deletions

diff --git a/runtime/lua/vim/fs.lua b/runtime/lua/vim/fs.lua
index a0d2c4c339..2c3fc64d57 100644
--- a/runtime/lua/vim/fs.lua
+++ b/runtime/lua/vim/fs.lua
@@ -144,11 +144,34 @@ end
 --- The search can be narrowed to find only files or only directories by
 --- specifying {type} to be "file" or "directory", respectively.
 ---
----@param names (string|table|fun(name: string): boolean) Names of the files
+--- Examples:
+--- <pre>lua
+--- -- location of Cargo.toml from the current buffer's path
+--- local cargo = vim.fs.find('Cargo.toml', {
+---   upward = true,
+---   stop = vim.loop.os_homedir(),
+---   path = vim.fs.dirname(vim.api.nvim_buf_get_name(0)),
+--- })
+---
+--- -- list all test directories under the runtime directory
+--- local test_dirs = vim.fs.find(
+---   {'test', 'tst', 'testdir'},
+---   {limit = math.huge, type = 'directory', path = './runtime/'}
+--- )
+---
+--- -- get all files ending with .cpp or .hpp inside lib/
+--- local cpp_hpp = vim.fs.find(function(name, path)
+---   return name:match('.*%.[ch]pp$') and path:match('[/\\\\]lib$')
+--- end, {limit = math.huge, type = 'file'})
+--- </pre>
+---
+---@param names (string|table|fun(name: string, path: string): boolean) Names of the files
 ---             and directories to find.
----             Must be base names, paths and globs are not supported.
----             The function is called per file and directory within the
----             traversed directories to test if they match {names}.
+---             Must be base names, paths and globs are not supported when {names} is a string or a table.
+---             If {names} is a function, it is called for each traversed file and directory with args:
+---             - name: base name of the current item
+---             - path: full path of the current item
+---             The function should return `true` if the given file or directory is considered a match.
 ---
 ---@param opts (table) Optional keyword arguments:
 ---                       - path (string): Path to begin searching from. If
@@ -201,7 +224,7 @@ function M.find(names, opts)
       test = function(p)
         local t = {}
         for name, type in M.dir(p) do
-          if names(name) and (not opts.type or opts.type == type) then
+          if (not opts.type or opts.type == type) and names(name, p) then
             table.insert(t, join_paths(p, name))
           end
         end
@@ -250,7 +273,7 @@ function M.find(names, opts)
       for other, type_ in M.dir(dir) do
         local f = join_paths(dir, other)
         if type(names) == 'function' then
-          if names(other) and (not opts.type or opts.type == type_) then
+          if (not opts.type or opts.type == type_) and names(other, dir) then
             if add(f) then
               return matches
             end