GitHub Action: Comment Parser

I Am C-3PO, Human/Cyborg Relations. And You Are?

The action parses comments using predefined patterns. It will create the output parameters in case of a match with the pattern. This action can be used to control various CI/CD processes by specifying commands in comments or descriptions of Issues or Pull Requests.

Example usage

Note: issue_comment event will only trigger a workflow run if the workflow file is on the default branch.

.github/workflow/droid.yml

name: droid
on:
  issue_comment:
    types: [ created ]
jobs:
  uses:
    runs-on: ubuntu-latest
    steps:
    - uses: blablacar/action-c-3po-droid@master
      id: c-3po
      with:
        expect: |
          - pattern: ^/hello (?<value>.+)$
          - pattern: ^/chances (?<output>[^=]+)=(?<value>.*)$
          - command: intrusion
          - command: disappeared
            value: R2-D2

    - if: ${{ steps.c-3po.outputs.is-hello }}
      run: echo "${{ steps.c-3po.outputs.has-hello }}, it is you, it Is You!"

    - if: ${{ steps.c-3po.outputs.is-chances && steps.c-3po.outputs.has-chances-survival }}
      run: echo "R2 says the chances of survival are ${{ steps.c-3po.outputs.has-chances-survival }}... to one"

    - if: ${{ steps.c-3po.outputs.is-chances && steps.c-3po.outputs.has-chances-win > 0 }}
      run: echo "We'll take the next chance, and the next."

    - if: ${{ steps.c-3po.outputs.is-intrusion }}
      run: echo "We're doomed"

    - if: ${{ steps.c-3po.outputs.is-disappeared }}
      run: echo "${{ steps.c-3po.outputs.has-disappeared }}, where are you?"

Then try adding comments to the Issue with the following content:

• /hello R2-D2
• /chances survival=725
• /chances win=5
• /intrusion
• /disappeared who?

Inputs

expect

A list of objects with patterns and output settings. This field contains a string with a list in YAML format:

- command: <command name>
  pattern: <regex>
  output: <output key>
  value: <value>

Each object must have a command or pattern parameter. After processing the first match in a row, subsequent patterns are ignored for that row.

command

Optional. Specifies the command of the team to be searched for at the beginning of each new comment line. The command in the comment must start with the / character. You do not need to specify this / character in the command parameter. The action returns the output parameters is-<command>, has-<command> or has-<command>-<output key> when the command is found in the comment.

Example:

- command: hello

Will be a trigger for a comment:

/hello world

The action will return the parameters:

steps.<id>.outputs.is-hello = '/hello world'
steps.<id>.outputs.has-hello = 'world'

pattern

Optional. Specifies a regex pattern according to which a match will be searched for in the new comment. If the command is not defined, it can be determined by the first word that begins in the pattern after ^/.

The pattern may contain regex named capturing groups that will determine the output key, or data for the output parameters.

• (?<output>...) — determines the output key that is appended to the name of the output parameter has-<command>-<output key>.
• (?<value>...) - determines the data that is contained in the output parameter has-*.

Example:

- pattern: ^/set (?<output>.+)=(?<value>.*)$

Will be a trigger for a comment:

/set hello=world

The action will return the parameters:

steps.<id>.outputs.is-set = '/set hello=world'
steps.<id>.outputs.has-set-hello = 'world'

output (experimental)

Optional. Contains the output key that is appended to the name of the output parameter has-<command>-<output key>. Has a higher priority for the named capturing groups in the regex pattern.

value (experimental)

Optional. Contains the data that is contained in the output parameter has-*. Has a higher priority for the named capturing groups in the regex pattern.

in

Optional. Determines the type of problems in the comments which will be searched for matching patterns. Possible values are issue, pull_request or any. The default is any.

description

Optional. Looks for pattern matches in the description at Issue or Pull Request creation if true is set. The default is false.

Outputs

commands

Return a list of parsed commands. In JSON format. List items have the optional attributes command, output and value.

is-<command>

Returns the contents of a row if a pattern or command is matched. This parameter is present if there is a specified command name in the command or pattern parameter.

has-<command>

Returns the data defined by value, or the content in the line after the command. This parameter is present if there is a specified:

• command name in the command or pattern parameter
• value in pattern or value parameter.

has-<command>-<output key>

Returns the data defined by value, or the content in the line after the command. This parameter is present if there is a specified:

• command name in the command or pattern parameter
• output key in pattern or output parameter
• value in pattern or value parameter.

has-<output key>

Returns the data defined by value, or the content in the line after the command. This parameter is present if there is a specified:

• output key in pattern or output parameter
• value in pattern or value parameter. Also, no command name is specified.

License

The scripts and documentation in this project are released under the MIT License