Introduce selective triggers

[godrei]

Checklist

• I've read and followed the Contribution Guidelines
• README.md is updated with the changes (if needed)

Version

Requires a MINOR version update

Context

This PR introduced bitrise.yml data model changes to support selective build triggering (per workflow and pipeline build triggers).

Changes

• WorkflowModel and PipelineModel got a new Triggers property
• the new Triggers property is a structure with (for now) tree fields, that reflect the matching git event type:PushTriggers,PullRequestTriggers, and TagTriggers
• PushTriggers ,PullRequestTriggers , andTagTriggers are lists of the related trigger items
• trigger items follow the same structure as currently, except that type, workflow, and pipeline fields are not needed anymore and event type related parts are removed from the filter field names:
  • push trigger items' fields:
    • push_branch → branch
    • commit_message
    • changed_files
    • enabled
  • pull_request trigger items' fields:
    • pull_request_source_branch → source_branch
    • pull_request_target_branch → target_branch
    • pull_request_label → label
    • draft_pull_request_enabled → draft_enabled
    • pull_request_comment → comment
    • commit_message
    • changed_files
    • enabled
  • tag trigger item’s fields:
    • tag → name
    • enabled

Since the new triggers follow a slightly different structure than the original trigger map, the new Triggers model is manually parsed by implementing the yaml.Unmarshaler interface, to be able to warn users about misconfiguration.

E.g.: if you simply move an existing trigger map under a workflow's triggers, with the default yaml parsing bitrise validate would give this error message:

Config is valid: false
Error: config (./bitrise.yml) is not valid: yaml: unmarshal errors:
  line 12: cannot unmarshal !!seq into models.Triggers

with the custom parsing, this is the error message:

Config is valid: false
Error: config (./bitrise.yml) is not valid: 'triggers': should be a map with 'push', 'pull_request' and 'tag' keys

[ofalvai]

nit: why not Stringer.String()? https://pkg.go.dev/fmt#Stringer

[godrei]

Because these toString functions are helper functions for finding duplicated items, the Enabled property is omitted when comparing two items.