renovate.json
{
"$schema": "https://docs.renovatebot.com/renovate-schema.json",
"dependencyDashboard": true,
"regexManagers": [
{
"fileMatch": ["(^|/)\\w+.gemspec"],
"matchStrings": ["\\n\\s*\\w*.add_(?:development_)?dependency\\s*[\"'](?<depName>.+?)[\"']\\s*,\\s*[\"'](?<currentValue>.+?)[\"']"],
"datasourceTemplate": "rubygems"
}
]
}