YAML type coercion in description documents

[commonism]

Due to yaml type coercion certain values get converted to objects.

E.g. timestamps to datetime objects:

import datetime, yaml
yaml.safe_load(str(datetime.datetime.now().date()))
# datetime.date(2022, 6, 10)

Therefore I'd like to have your opinion in having such values in a description document, such as:

openapi-directory/APIs/1password.com/events/1.0.0/openapi.yaml

Lines 176 to 179 in 3b42800

	DateTimeRFC3339:
	example: 2020-06-11T16:32:50-03:00
	format: date-time
	type: string

openapi-directory/APIs/amadeus.com/2.2.0/openapi.yaml

Lines 54 to 56 in 3b42800

	- description: the date on which the traveler will depart from the origin to go to the destination. Dates are specified in the [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) YYYY-MM-DD format, e.g. 2017-12-25
	example: 2021-02-01
	in: query

openapi-directory/APIs/api.video/1/openapi.yaml

Lines 76 to 84 in 3b42800

	- description: |
	Period must have one of the following formats:
	- For a day : "2018-01-01",
	- For a week: "2018-W01",
	- For a month: "2018-01"
	- For a year: "2018"
	For a range period:
	- Date range: "2018-01-01/2018-01-15"
	example: 2019-01-01

openapi-directory/APIs/apidapp.com/2019-02-14T164701Z/openapi.yaml

Lines 4 to 8 in 3b42800

	info:
	contact:
	x-twitter: api_dapp
	title: ApiDapp
	version: 2019-02-14T16:47:01Z

openapi-directory/APIs/apideck.com/accounting/8.32.1/openapi.yaml

Lines 4720 to 4722 in 3b42800

	created_at:
	example: 2020-09-30T07:43:32.000Z
	format: date-time

[MikeRalphson]

Which YAML parser and version are you using? js-yaml used to have problems handling dates but I thought that had been fixed...

[commonism]

Python3 - PyYAML 6.0

I do not consider this a problem with the YAML parser, from my understanding the parser does things according to the specification.

To me this is a problem of the description document not forcing this to be a string either enclosing in "" or via !!str.

I consider the dd invalid by having datetime objects where string is expected.

[MikeRalphson]

Do you know if pyYAML supports YAML 1.2 or 1.1 only?

[commonism]

1.1

[MikeRalphson]

These documents are YAML 1.2, as recommended by the OpenAPI Specification:

In order to preserve the ability to round-trip between YAML and JSON formats, YAML version 1.2 is RECOMMENDED

As we basically have no control over the YAML output by our chosen yaml parser, I'm unfortunately going to close this as not-a-bug.

[commonism]

YAML 1.2 does not change anything here.

As an example, ruamel.yaml does YAML 1.2:

from ruamel.yaml import YAML
yaml = YAML()
yaml.load("example: 2020-06-11T16:32:50-03:00")
# ordereddict([('example', TimeStamp(2020, 6, 11, 19, 32, 50))])

example expects string.

This makes this not a valid description document?

[MikeRalphson]

From https://yaml.org/spec/1.2.2/ext/changes/

Changes in version 1.2 (revision 1.2.0) (2009-07-21)
The !!pairs, !!omap, !!set, !!timestamp and !!binary types have been dropped.

eemeli/yaml only parses timestamp-like strings as Dates if a YAML 1.1 directive is included or !!timestamp is added as a custom type.

[commonism]

I wrongly assumed that ruamel.yaml would use the Core schema for 1.2 documents.

Seems I'm all wrong with this one.

[MikeRalphson]

It doesn't help that the YAML 1.2 spec contains three (orphan?) references to !! timestamp without explicitly referencing where it comes from.

[MikeRalphson]

Closing due to inactivity - but please feel free to chase and we can reopen the issue if necessary.