Description

This pull request introduces the extends capabilities in the Reviewpad configuration.

The extends feature works as follows.

The user can specify in the Reviewpad configuration a list of other Reviewpad configuration files as GitHub blob urls (e.g. https://github.com/reviewpad/reviewpad/blob/main/reviewpad.yml).

As example:

api-version: reviewpad.com/v3.x

extends:
  - https://github.com/reviewpad/reviewpad/blob/main/common_team.yml
  - https://github.com/reviewpad/reviewpad/blob/main/specific_team_a.yml

The final configuration will be the concatenation of all configurations included in the extends and the contents of the current configuration.

The extended configuration will be included in the order they are specified in the "extends" section.

If properties have the same name, the one that was defined last overrides the previous ones.

For example:

api-version: reviewpad.com/v3.x

extends:
  - https://github.com/reviewpad/reviewpad/blob/main/common_team.yml
  - https://github.com/reviewpad/reviewpad/blob/main/specific_team_a.yml
 
workflows:
  - name: add-label-with-small-size
    if:
      - rule: $size() < 30
    then:
      - '$info("this is a small pr")'

Where common_team:

api-version: reviewpad.com/v3.x
 
workflows:
  - name: add-label-with-small-size
    if:
      - rule: $size() < 5
    then:
      - '$info("this is a very small pr")'
  - name: add-label-with-medium-size
    if:
      - rule: $size() >= 30
    then:
      - '$info("this is not a small pr")'
      - '$assignRandomReviewer()'

and specific_team_a:

api-version: reviewpad.com/v3.x
 
workflows:
  - name: add-label-with-small-size
    if:
      - rule: $size() < 10
    then:
      - '$info("this is a small pr for team a")'
  - name: add-label-with-medium-size
    if:
      - rule: $size() >= 30
    then:
      - '$info("this is not a small pr")'

The final configuration will be:

api-version: reviewpad.com/v3.x
 
workflows:
  - name: add-label-with-medium-size
    if:
      - rule: $size() >= 30
    then:
      - '$info("this is not a small pr")'
  - name: add-label-with-small-size
    if:
      - rule: $size() < 30
    then:
      - '$info("this is a small pr")'

Follow-up:

• Add more unit tests to increase the coverage of this feature (in particular the (r *ReviewpadFile) extends(o *ReviewpadFile) function)
• Add logging information to notify users that labels, groups, rules, workflows or pipelines were overridden.
• Add mixpanel event whenever a configuration uses the extends feature.

Related issue

Closes #306

Type of change

New feature (non-breaking change which adds functionality)

How was this tested?

Added unit tests to the loader that also check the DownloadContents of the GitHub API.

Checklist

• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works
• I have ran task check -f and have no issues

Code review and merge strategy (ship/show/ask)

• Ask: this pull request requires a code review before merge