fix: catch unsupported format errors

src/index.js

@@ -10,14 +10,16 @@ const args = (flags = {}) => dargs(flags, { useEquals: false }).filter(Boolean)
 const isJSON = (str = '') => str.startsWith('{')
 
 const parse = ({ stdout, stderr, ...details }) => {
-  if (stdout !== undefined && stdout !== '' && stdout !== 'null') {
-    return isJSON(stdout) ? JSON.parse(stdout) : stdout
-  }
+  if (details.exitCode === 0) { return isJSON(stdout) ? JSON.parse(stdout) : stdout }
   throw Object.assign(new Error(stderr), { stderr, stdout }, details)
 }
 
 const create = binaryPath => {
-  const fn = (...args) => fn.exec(...args).then(parse).catch(parse)
+  const fn = (...args) =>
+    fn
+      .exec(...args)
+      .then(parse)
+      .catch(parse)
   fn.exec = (url, flags, opts) => $(binaryPath, [url].concat(args(flags)), opts)
   return fn
 }

test/error.js

@@ -6,6 +6,8 @@ const test = require('ava')
 
 const youtubedl = require('..')
 
+const isCI = !!process.env.CI
+
 test.serial('catch errors', async t => {
   await rename(path.resolve('bin/yt-dlp'), path.resolve('bin/_yt-dlp'))
   t.teardown(() =>
@@ -38,6 +40,30 @@ test('unsupported URLs', async t => {
     t.truthy(error.exitCode)
   }
 })
+;(isCI ? test.skip : test)('unsupported format', async t => {
+  t.plan(6)
+  const url = 'https://www.youtube.com/watch?v=tPEE9ZwTmy0'
+  try {
+    await youtubedl(url, {
+      extractorArgs: 'youtube:player_client=android,web'
+    })
+  } catch (error) {
+    t.is(
+      error.message,
+      [
+        'WARNING: [youtube] tPEE9ZwTmy0: android client https formats require a PO Token which was not provided. They will be skipped as they may yield HTTP Error 403. You can manually pass a PO Token for this client with --extractor-args "youtube:po_token=android+XXX. For more information, refer to  https://github.com/yt-dlp/yt-dlp/wiki/Extractors#po-token-guide . To enable these broken formats anyway, pass --extractor-args "youtube:formats=missing_pot"',
+        'WARNING: [youtube] tPEE9ZwTmy0: web client https formats require a PO Token which was not provided. They will be skipped as they may yield HTTP Error 403. You can manually pass a PO Token for this client with --extractor-args "youtube:po_token=web+XXX. For more information, refer to  https://github.com/yt-dlp/yt-dlp/wiki/Extractors#po-token-guide . To enable these broken formats anyway, pass --extractor-args "youtube:formats=missing_pot"',
+        'WARNING: Only images are available for download. use --list-formats to see them',
+        'ERROR: [youtube] tPEE9ZwTmy0: Requested format is not available. Use --list-formats for a list of available formats'
+      ].join('\n')
+    )
+    t.true(error instanceof Error)
+    t.truthy(error.command)
+    t.truthy(error.stderr)
+    t.truthy(error.stdout)
+    t.truthy(error.exitCode)
+  }
+})
 
 test('video unavailable', async t => {
   t.plan(4)