Yamllint

brew install yamllint

yamllint
usage: yamllint [-h] [-] [-c CONFIG_FILE | -d CONFIG_DATA]
                [-f {parsable,standard,colored,github,auto}] [-s]
                [--no-warnings] [-v]
                [FILE_OR_DIR ...]
yamllint: error: one of the arguments FILE_OR_DIR - is required
mcebollada@DESKTOP-OVLCHPF ~ % yamllint --help
usage: yamllint [-h] [-] [-c CONFIG_FILE | -d CONFIG_DATA]
                [-f {parsable,standard,colored,github,auto}] [-s]
                [--no-warnings] [-v]
                [FILE_OR_DIR ...]

A linter for YAML files. yamllint does not only check for syntax validity, but
for weirdnesses like key repetition and cosmetic problems such as lines
length, trailing spaces, indentation, etc.

positional arguments:
  FILE_OR_DIR           files to check

options:
  -h, --help            show this help message and exit
  -                     read from standard input
  -c CONFIG_FILE, --config-file CONFIG_FILE
                        path to a custom configuration
  -d CONFIG_DATA, --config-data CONFIG_DATA
                        custom configuration (as YAML source)
  -f {parsable,standard,colored,github,auto}, --format {parsable,standard,colored,github,auto}
                        format for parsing output
  -s, --strict          return non-zero exit code on warnings as well as
                        errors
  --no-warnings         output only error level problems
  -v, --version         show program's version number and exit

See also

• YAML, yq, Dhall, YAML anchors, yamllint