how use optional parameters in cucumber

Question

I want the same Gherkin sentence (with paramaters and without paramaters):

Gherkin with paramaters:

When a 'notify' message is sent to the green box with the properties.
 |type|message|
 |error|The error message|

Gherkin without paramaters:

When a 'notify' message is sent to the green box with the properties.

Java (cucumber):

@When("^a '(.*)' message is sent to the green box with the properties.$")
public void hello(String name, List<GherkinCondition> conditions) {
    ...
}

I have a error because java method is is declared with 2 parameters and in the case "without paramaters" I have only one.

stack trace:

cucumber.runtime.CucumberException: Arity mismatch: Step Definition 'steps.CommonSteps.hello(String,GherkinCondition>) in file:/C:/workspace/xxxxx/java/target/classes/' with pattern [^a '(.*)' message is sent to the green box with the properties.$] is declared with 2 parameters. However, the gherkin step has 1 arguments [notify]. 

Answer 1

I create a PR for resolve this problem: https://github.com/cucumber/cucumber-jvm/pull/1056

Gherkin script test:

@hello 
Feature: hello (Function to validate the environment.) 

    Scenario Outline: Function to validate the environment.
        Given me a hello, please. Best Regards '<author>'.
        Given me a hello, please. Best Regards '<author>'.
            |key|expected|actual|
        Given me a hello, please. Best Regards '<author>'.
            |key|expected|actual|
            |zip|35000|<zip>|
            |city|Rennes|<city>|

        Given me a bye, please. Best Regards '<author>'.
        Given me a bye, please. Best Regards '<author>'.
            |zip|<zip>|
            |city|<city>|

        Given me a cat, please. Best Regards '<author>'.

    Examples:
    #Begin Examples#
    |author|zip|city|
    |Jenkins Q1|35000|Rennes|
    |Jenkins Q2|35000|Rennes|
    #End Examples#

Java Cucumber code:

    @Given("^me a hello, please. Best Regards '(.*)'.$")
    public void hello(String name, List<GherkinCondition> conditions) {
        int i = 0;
        for (GherkinCondition gherkinCondition : conditions) {
            i++;
            logger.info(String.format("  expected contition N°%d=%s", i, gherkinCondition.getExpected()));
            logger.info(String.format("  actual   contition N°%d=%s", i, gherkinCondition.getActual()));
        }
        logger.info("Hello " + name + "!");
    }

    @Given("^me a cat, please. Best Regards '(.*)'.$")
    public void hello(String name) {
        logger.info("Take my cat " + name + "!");
    }

    @Given("^me a bye, please. Best Regards '(.*)'.$")
    public void bye(String name, Map<String, String> params) {
        int i = 0;
        for (Map.Entry<String, String> entry : params.entrySet()) {
            i++;
            logger.info(String.format("  Key N°%d: %s   Value:%s", i, entry.getKey(), entry.getValue()));
        }
        logger.info("Bye " + name + "!");
    }