check-yaml false positive on unquoted scalar values with colon (e.g. URL) using flow style lists

[tales-aparecida]

The check-yaml hook fails from v2.2.0 onward for scalar values containing a colon without quotes, for the example an URL:

[https://github.com/]

$ pre-commit run check-yaml --verbose --files example.yaml 
Check Yaml...............................................................Failed
- hook id: check-yaml
- duration: 0.05s
- exit code: 1

while scanning a plain scalar
  in "example.yaml", line 1, column 2
found unexpected ':'
  in "example.yaml", line 1, column 7

I believe this is a valid value since there's no space after the colon, as mentioned at pycontribs/ruyaml#86.

This issue can't be avoided by using the --unsafe argument, and this errors does not happen when using v2.1.0, when the hook was still using pyYAML instead of ruamel-yaml.

There's a ticket tracking this issue in there, but the solution provided involves using the Python interpreter instead of the C library. https://sourceforge.net/p/ruamel-yaml/tickets/248/
That would indeed solve the issue, but would be slower.

The workaround, besides using v2.1.0, is to wrap the value in quotes or use multi line lists.

[asottile]

please search the issue tracker, there's at least one duplicate