`xo` is slow on `eslint-plugin-unicorn` project

[fisker]

I've locate problems, it's because

xo/index.js

Lines 100 to 105 in 0ec4b8c

	const configFiles = (await Promise.all(
	(await globby(
	CONFIG_FILES.map(configFile => `**/${configFile}`),
	{ignore: DEFAULT_IGNORES, gitignore: true, cwd: options.cwd}
	)).map(async configFile => configExplorer.load(path.resolve(options.cwd, configFile)))
	)).filter(Boolean);

searching xo config files, and eslint-plugin-unicorn has many files in test/integration/fixtures dir, and we can't set config search ignore dirs.

Questions:

1. Why are we searching config files inside dirs? Shouldn't config file in cwd or above?
2. Why don't we use cosmiconfig.search? Because it don't know how to mergeOptions?

[sindresorhus]

Why are we searching config files inside dirs? Shouldn't config file in cwd or above?

I'm honestly not sure. It was added in: 0d63c64 Maybe there's some clue in there...

Why don't we use cosmiconfig.search? Because it don't know how to mergeOptions?

I don't have an answer for this either.

---

Maybe @pvdlg would be able to chime in.

[fisker]

The config searching logic also effect glob matching, if there is a xo.config.js file in subdir, xo won't format files outside that dir.

Run

node cli lib/*.js

on this project root dir, it won't match any file, because there are many config files in test/fixtures

[fisker]

I think we can close this now, it's much faster after #583, #510 (comment) also fixed by #583