René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"how to handle undefined values cleanly?","articleBody":"I'm `dump` ing an object, and fields without values come out like this:\r\n\r\n`fieldName: !\u003ctag:yaml.org,2002:js/undefined> ''`\r\n\r\nhow can I suppress that to either `undefined` or just to skip it like `JSON.stringify` ?\r\n\r\nI tried some options from the `safeDump` \r\n\r\n`const blob = yaml.dump(obj, { skipInvalid: true, lineWidth: 200 })`\r\n\r\nhttps://github.com/nodeca/js-yaml#safedump-object---options-\r\n\r\nbut without success. I guess I can strip out the undefined fields, but I'd have to do a `deep` clean of the whole object... also check for `false` vs `undefined` etc. etc.\r\n\r\nI tried this but it didn't have any effect:\r\n`const clean = { ...obj } // remove nulls?` \r\n\r\nSure there must be a nicer way to handle this with `js-yaml` ?\r\nDo I have to define my own schema?\r\n\r\nrelated:\r\nhttps://github.com/nodeca/js-yaml/issues/456\r\nhttps://stackoverflow.com/a/38340374/1146785\r\n\r\n\r\n```js\r\n\r\n  async debugMessage(obj) {\r\n    console.log('json', JSON.stringify(obj, null, 2))\r\n    const blob = yaml.dump(obj)\r\n    console.log('yaml', blob)\r\n  }\r\n\r\n\r\n// json \r\n\r\n{\r\n  \"msg\": \"router\",\r\n  \"input\": \"sleep\",\r\n  \"eventType\": \"action\",\r\n  \"handled\": {\r\n    \"handled\": true,\r\n    \"doc\": {\r\n      \"match\": \"^cont|.*\",\r\n      \"goto\": \"prologue\"\r\n    },\r\n    \"klass\": \"room\",\r\n    \"history\": [\r\n      \"goto\"\r\n    ]\r\n  }\r\n}\r\n\r\n// yaml \r\n\r\nmsg: router\r\ninput: sleep\r\neventType: action\r\nparsed: !\u003ctag:yaml.org,2002:js/undefined> ''\r\nhandled:\r\n  handled: true\r\n  doc:\r\n    match: ^cont|.*\r\n    goto: prologue\r\n  klass: room\r\n  history:\r\n    - goto\r\n\r\n````\r\n","author":{"url":"https://github.com/dcsan","@type":"Person","name":"dcsan"},"datePublished":"2020-07-25T23:43:52Z","url":"https://github.com/nodeca/js-yaml/issues/571"}