Step if condition starting with ! fails parsing

[EnricoMi]

Describe the bug
My workflow has a step if condition that starts with a ! to negate the expression. The yaml file cannot be parsed: While parsing a tag, did not find expected tag URI.

To Reproduce
Steps to reproduce the behavior:

1. Add this yaml to your repo under .github/workflow/:

name: "Issue"
on: [push]

jobs:
  condition:
    name: "Condition Issue"
    runs-on: ubuntu-latest

    steps:
    - name: Not false condition
      if: ! false
      run: echo "works"

2. Commit and push to github, see the "Actions" tab, it will show you a failed action:

Expected behavior
The expression ! false should be resolved to true. This workflow file works when the expression is enclosed in round brackets: if: ( ! false ). Those brackets should not be required.

Runner Version and Platform

Version of your runner? Current

OS of the machine running the runner? Ubuntu

[davidkarlsen]

Try quoting the expression

[aabeling]

Had the same problem. Quoting the expression helped in my case.
But it is still a bug, isn't it?

[TingluoHuang]

https://cloudslang-docs.readthedocs.io/en/v1.0/yaml_overview.html#scalars-strings-numbers-values

! is a special char in YAML, so you have to escape it. 😢

[marcospgp]

Quoting the string with "" causes a syntax error with the GitHub Actions VSCode extension,

${{}} also shows up as red in if fields

And not using single quotes in contains(github.event.pull_request.labels.*.name, 'notests') also causes an error when running the workflow

So I had to resort to if: '!contains(github.event.pull_request.labels.*.name, ''notests'')'

So much complexity for such a simple thing 🥵