Convert YAML string issue

[hangwang200]

jackson-dataformat-yaml 2.8.11

read file config like this:

 gemfireSwitchForRegions:
    maxConnections: '20'
    user: 'OFF'
    legalEntity: 'ON'

----
java

ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory().enable(Feature.MINIMIZE_QUOTES));
JsonNode jsonNode = objectMapper.readTree(inputStream);
SequenceWriter sw = objectMapper.writer().writeValues(System.out);
sw.write(jsonNode);

----
output:

  gemfireSwitchForRegions:
    maxConnections: 20
    user: OFF
    legalEntity: ON

read file config like this:

 gemfireSwitchForRegions:
    maxConnections: '20'
    user: OFF
    legalEntity: ON

----
java

ObjectMapper objectMapper = new ObjectMapper(new YAMLFactory().enable(Feature.MINIMIZE_QUOTES));
JsonNode jsonNode = objectMapper.readTree(inputStream);
SequenceWriter sw = objectMapper.writer().writeValues(System.out);
sw.write(jsonNode);

----
output:

  gemfireSwitchForRegions:
    maxConnections: 20
    user: false
    legalEntity: true

why in the first case it will convert it will output OFF/ON, but when it reads OFF/ON, it will change to false/true?

[cowtowncoder]

This is because YAML has weird rules on accepting many strange Strings as booleans, unless explicitly quoted to avoid such handling.
See:

https://yaml.org/type/bool.html

[hangwang200]

OK, thanks for your information. It's really weird, so if I use Feature.MINIMIZE_QUOTES config, it can not keep the idempotent operation, right? (e.g. read "OFF" from a file and overwrite to OFF, and at the second time, it will read OFF and overwrite to false). Any suggestions for this case? can I prevent to transform OFF to false by adding configuration?

[cowtowncoder]

Ok, maybe #90 (to be included in 2.9.9) helps: it will force quoting of "truthy" values?

[hangwang200]

Hi cowtowncoder, I think I have found the reason.
In Yaml version 1.2, 'ON' should not convert to true, but it can be in Yaml version 1.1 as the link your provided.

and also, in https://yaml.org, I find information like this:

• SnakeYAML # Java 5 / YAML 1.1

because the jackson-dataformats-yaml depends on SnakeYAML, so it can not support the new version of yaml standard.

does jackson-dataformats-yaml have any idea about upgrade this? : )

[hangwang200]

https://yaml.org/spec/1.2/spec.html

[GuillaumeSmaha]

I think the values which can be implicitly converted, should be protected when the option MINIMIZE_QUOTES is enabled (See the list for in https://yaml.org/type/bool.html).
It looks like the same issue with the boolean-like string fixed in FasterXML/jackson-dataformat-yaml#78

[cowtowncoder]

Thank you for contributing this! I'll be off until next week, and there's bit of backlog, but I added this on my todo list hoping to get that in before 2.0.0.pr1.