Wrong front matter interpretation

[BnGx]

Description

The yamlfmt program does not evaluate the frontmatter correctly when already present in the yaml file and the formatter configuration specifies include_document_start with true.

The problem is evident when there are particular comments such as the vim modelines before the frontmatter, if the latter is moved to line 1 the modeline is not evaluated correctly by the editors.

Steps to play

• Create a .yamlfmt configuration file and set the include_document_start option to true in the section formatter;
• Create a yaml file with a modeline on line 1, the front matter on line 2 and arbitrary content starting from line 3.
• Run yamlfmt on the created yaml file.

Expected behavior

If the front matter is already present in the file and preceded by comments, it should not be moved to the first line of the file.

If it is not present you should insert it after modelines or after all the initial comments before the first valid yaml line.

Scripts

echo "# vim: ft=yaml" > myfile.yaml
echo "---" >> myfile.yaml
echo "# My comment" >> myfile.yaml
echo "mycontent: yes" >> myfile.yaml
echo "formatter: {include_document_start: true}" > .yamlfmt
yamlfmt myfile.yaml

Environment details

• Operating system: Ubuntu 22.04
• Yamlfmt version: 0.10.0
• Shell used: bash

[braydonk]

This looks similar to #74. Similar to the other issues with the underlying yaml library, I'm not sure if I will be able to get to it anytime soon unfortunately.