Update dependency yargs to v17 (#382)

* Update dependency yargs to v17

* Fix coercion

* Add tests for coersion

Co-authored-by: Renovate Bot <bot@renovateapp.com>
Co-authored-by: Ryan Zimmerman <opensrc@ryanzim.com>

lib/args.js

@@ -13,7 +13,7 @@ const logo = `
                       //_____||___*_________*___||_____//
 `
 
-module.exports = require('yargs')
+const { argv } = require('yargs')
   .usage(
     `${bold(red(logo))}
 Usage:
@@ -88,10 +88,6 @@ Usage:
     desc: 'Override the output file extension; for use with --dir',
     type: 'string',
     implies: 'dir',
-    coerce(ext) {
-      if (ext.indexOf('.') !== 0) return `.${ext}`
-      return ext
-    },
   })
   .option('base', {
     desc: 'Mirror the directory structure relative to this path in the output directory, for use with --dir',
@@ -126,4 +122,8 @@ If there are multiple input files, the --dir or --replace option must be passed.
 Input files may contain globs (e.g. src/**/*.css). If you pass an input directory, it will process all files in the directory and any subdirectories, respecting the glob pattern.
 
 For more details, please see https://github.com/postcss/postcss-cli`
-  ).argv
+  )
+
+if (argv.ext && argv.ext.indexOf('.') !== 0) argv.ext = `.${argv.ext}`
+
+module.exports = argv

package.json

@@ -29,7 +29,7 @@
     "pretty-hrtime": "^1.0.3",
     "read-cache": "^1.0.0",
     "slash": "^3.0.0",
-    "yargs": "^16.0.0"
+    "yargs": "^17.0.0"
   },
   "devDependencies": {
     "ava": "^3.1.0",

test/ext.js

@@ -23,3 +23,20 @@ test('--ext works', async (t) => {
 
   t.truthy(await fs.pathExists(path.join(dir, 'a.css')))
 })
+
+test('--ext works with no leading dot', async (t) => {
+  const dir = tmp()
+
+  const { error, stderr } = await cli([
+    'test/fixtures/a.sss',
+    '--parser',
+    'sugarss',
+    '-d',
+    dir,
+    '--ext',
+    'css',
+  ])
+  t.falsy(error, stderr)
+
+  t.truthy(await fs.pathExists(path.join(dir, 'a.css')))
+})