Stringify method remove Date Objects with empty object

[seiya-git]

Stringify method remove Date Objects with empty object

const yaml = require('yaml');
const myDate = new Date();
const yamlStr = yaml.stringify(myDate);
console.log(myDate);
console.log(yamlStr);

output:

2018-12-22T07:29:51.234Z

{}

[Hamper]

With timestamp tag also don't work:

const yaml = require('yaml')
const { timestamp } = require ('yaml/types/timestamp')

yaml.defaultOptions.tags = [timestamp]

let x = yaml.parse('2018-12-22 08:02:52')
// 2018-12-22T08:02:52.000Z
yaml.stringify(x)
// '{}\n'

[eemeli]

This turned out to be two different but overlapping issues.

The original posted by @seiya-git was due to the internally-called createNode function not looking for a toJSON method on the input value (as provided e.g. by Date). Adding support for this should also help in other cases, such as Immutable.js collections.

In the case posted by @Hamper the mistake was in calling the schema-free createNode in the first place, as the right thing to do here is to keep the value as a Date and to get the !!timestamp tag to handle it directly. That should now happen thanks to an instanceof tagObj.class lookup, and it's even further customisable by defining a tagObj.createNode(value) function (required for non-scalar custom tags).

As these technically count as new features, I'll include them in the next minor release, probably at the same time as adding blank-line support. I'm also tempted to add support for !!set using the new tagObj.createNode functionality.

Once released, this is how it'll work:

const date = new Date('2018-12-22T08:02:52Z')

YAML.stringify(date)
  // '2018-12-22T08:02:52.000Z\n'

YAML.stringify(date, { version: '1.1' })
  // '2018-12-22T08:02:52\n'