cucumber-expressions: Invalid snippets generated for escaped optional

[mpkorstanje]

Spotted on stack overflow:

https://stackoverflow.com/questions/61725664/is-it-not-possible-to-have-a-step-definition-with-no-parameters

The following scenario:

Feature: Spheres
  Scenario: A ray intersects a sphere at two points
    Given r ← ray(point(0, 0, -5), vector(0, 0, 1))
    And s ← sphere()
    When xs ← intersect(s, r)
    Then xs.count = 2
    And xs[0] = 4.0
    And xs[1] = 6.0

Trying to keep it simple, I thought I'd write the step definition literally to start off:

import io.cucumber.java8.En

class SphereStepDefinitions: En {
    private val epsilon: Double = 0.00001
    lateinit var s: Sphere
    lateinit var xs : List<Double>

    init {
        Given("s ← sphere\\()") {
            s = Sphere()
        }
    }
}

The result,

The step "s ← sphere()" is undefined. You can implement it using the snippet(s) below:

Given("s ← sphere\\()", () -> {
    // Write code here that turns the phrase above into concrete actions
    throw new io.cucumber.java8.PendingException();
});

The correct step definition is:

s ← sphere()

Because

    private static final Pattern OPTIONAL_PATTERN = Pattern.compile("(\\\\\\\\)?\\(([^)]+)\\)");

Does not allow empty capture groups.

Probably solved by implementing the parser for Cucumber Expressions rather then the current rewriting solution but we should check the snippet generation when we do.

[lav16kosh]

@mpkorstanje I changed the optional_pattern to (\\\\)?\(([^)]*)\) to include step definition with no parameters.

And I created a test in CucumberExpressionTest.java to verify with no parameters. It worked fine.

Do we have to do any other check to resolve this issue?

[mpkorstanje]

That would work but it would be breaking changes in cucumber expressions. If breaking changes are to be made I'd rather bundle them all up as part of #771

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in a week if no further activity occurs.

[aslakhellesoy]

@mpkorstanje can we close this now? I believe this was fixed as part of #771.