reference

node_modules/semver/functions/prerelease.js

@@ -0,0 +1,6 @@
+const parse = require('./parse')
+const prerelease = (version, options) => {
+  const parsed = parse(version, options)
+  return (parsed && parsed.prerelease.length) ? parsed.prerelease : null
+}
+module.exports = prerelease