Rule is not supported

[michaelsauter]

What version of godog are you using?

> godog version: 0.12.2

What version of Go are you using?

> go version: 1.16

What did you do?

Given a feature file like the following:

Feature: simple feature
  simple feature description

  Rule: simple rule
    Example: simple example

Running godog will panic:

panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x70 pc=0x11cc0c6]

goroutine 34 [running]:
github.com/cucumber/godog/internal/formatters.(*Pretty).printStep(0xc0002020d0, 0xc000250360, 0xc000208680)
        /Users/michaelsauter/go/pkg/mod/github.com/cucumber/godog@v0.12.2/internal/formatters/fmt_pretty.go:384 +0xf26

Additional context

I've looked a bit into the source code and added the following test to pretty.feature:

  Scenario: Support of Feature Plus Rule Node
    Given a feature "features/simple.feature" file:
    """
        Feature: simple feature
            simple feature description

        Rule: simple rule
            Scenario: simple scenario
                simple scenario description
    """
    When I run feature suite with formatter "pretty"
    Then the rendered output will be as follows:
    """
      Feature: simple feature
        simple feature description

        Rule: simple rule # features/simple.feature:3

        Scenario: simple scenario # features/simple.feature:4

      1 scenarios (1 undefined)
      No steps
      0s
    """

This lead me to apply the following fix in fmt_pretty.go:

func (f *Pretty) scenarioLengths(pickle *messages.Pickle) (scenarioHeaderLength int, maxLength int) {
	feature := f.Storage.MustGetFeature(pickle.Uri)
	astRule := feature.FindRule(pickle.AstNodeIds[0])
	astScenario := feature.FindScenario(pickle.AstNodeIds[0])
	astBackground := feature.FindBackground(pickle.AstNodeIds[0])

	if astScenario != nil {
		scenarioHeaderLength = f.lengthPickle(astScenario.Keyword, astScenario.Name)
		maxLength = f.longestStep(astScenario.Steps, scenarioHeaderLength)
	}

	if astBackground != nil {
		maxLength = f.longestStep(astBackground.Steps, maxLength)
	}
	if astRule != nil {
		for _, rc := range astRule.Children {
			if rc.Scenario != nil {
				maxLength = f.longestStep(rc.Scenario.Steps, maxLength)
			} else if rc.Background != nil {
				maxLength = f.longestStep(rc.Scenario.Steps, maxLength)
			}
		}
	}

	return scenarioHeaderLength, maxLength
}

... but there are many more issues in the pretty formatter, plus I realized all the other formatters would need to be fixed, too. Seems like supporting rules will be quite the effort. Are there plans to do this already?