fix: Handle multiline strings in yaml serialization.

[DanCardin]

Pull Request Checklist

• Fixes #
• Tests added
• Documentation/examples added
• Good commit messages and/or PR title

Description of PR
Currently, multiline strings serialize to yaml in a way that is not true to the original content.

For example, copying argo workflows' exit-handler example

excerpt:

      args: [
        "curl -X POST --data-urlencode 'payload={
          \"text\": \"{{workflow.name}} finished\",
          \"blocks\": [
            {
              \"type\": \"section\",
              \"text\": {
                \"type\": \"mrkdwn\",
                \"text\": \"Workflow {{workflow.name}} {{workflow.status}}\",
              }
            }
          ]
        }'
        YOUR_WEBHOOK_URL_HERE"
      ]

currently produces:

        args:
        - "curl -X POST --data-urlencode 'payload={\n          \"text\": \"{{workflow.name}}\
          \ finished\",\n          \"blocks\": [\n            {\n              \"\
          type\": \"section\",\n              \"text\": {\n                \"type\"\
          : \"mrkdwn\",\n                \"text\": \"Workflow {{workflow.name}} {{workflow.status}}\"\
          ,\n              }\n            }\n          ]\n        }'\n        YOUR_WEBHOOK_URL_HERE\"\
          \n        "

whereas this PR produces:

        args:
        - |-
          curl -X POST --data-urlencode 'payload={
                    "text": "{{workflow.name}} finished",
                    "blocks": [
                      {
                        "type": "section",
                        "text": {
                          "type": "mrkdwn",
                          "text": "Workflow {{workflow.name}} {{workflow.status}}",
                        }
                      }
                    ]
                  }'
                  YOUR_WEBHOOK_URL_HERE";

---

Note that this does not fix yaml/pyyaml#121 (comment). That is, the following example will revert back to original formatting due to the trailing \n at the end of the string.

args="""
two
"""

I would suggest switching ruamel.yaml over pyyaml just generally, which would fix this issue, but that's probably going to be considered a breaking change.

In any case is probably more tangential to the root issue above (which affects both libraries in the same way).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (4672a9b) 80.6% compared to head (1e82d34) 80.7%.

Additional details and impacted files

@@           Coverage Diff           @@
##            main    #935     +/-   ##
=======================================
+ Coverage   80.6%   80.7%   +0.1%     
=======================================
  Files         49      50      +1     
  Lines       3898    3908     +10     
  Branches     792     793      +1     
=======================================
+ Hits        3145    3157     +12     
+ Misses       565     564      -1     
+ Partials     188     187      -1     

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[flaviuvadan]

@DanCardin I think if you run a make regenerate-test-data this should regenerate all the docs and make the script field more readable for all of Hera's examples!

[DanCardin]

😱 neat! An even better way of exemplifying the benefit than my test, lol. Added as a 2nd commit, separate from the actual code change.

Just to check, are the literal examples that are being rewritten tested somehow to make sure this hasn't secretly broken the output somehow, even if it looks prettier?

[flaviuvadan]

😱 neat! An even better way of exemplifying the benefit than my test, lol. Added as a 2nd commit, separate from the actual code change.

Just to check, are the literal examples that are being rewritten tested somehow to make sure this hasn't secretly broken the output somehow, even if it looks prettier?

Yea, they're all tested here! It essentially compares the YAML output but without formatting concerns. As long as the content is valid, the tests pass.

Note that we also have Argo Workflows running in CI via k3d and we submit a few workflows to it. Those are created via the some to_yaml API, so if those work, then we know that:

• Hera serialization results in valid upstream examples
• examples are actually submittable / accepted by the Argo server + runnable by the controller

[flaviuvadan]

All those examples look sooo much better now 🎖️

[flaviuvadan]

We can 🚢 once @elliotgunton or @samj1912 approve too. Their stake in the CLI + YAML is larger than mine, so I want to be mindful of their input

[elliotgunton]

Awesome stuff! 🚀 The dodgy source dumping has been bugging me forever! 😆