1. Overview

1.概述

In this quick tutorial, we’ll learn how to use Java 8 lambda expressions with Cucumber.

在这个快速教程中，我们将学习如何在Cucumber中使用Java 8 lambda表达式。

2. Maven Configuration

2.Maven配置

First, we will need to add the following dependency to our pom.xml:

首先，我们将需要在我们的pom.xml中添加以下依赖关系。

<dependency>
    <groupId>info.cukes</groupId>
    <artifactId>cucumber-java8</artifactId>
    <version>1.2.5</version>
    <scope>test</scope>
</dependency>

The cucumber-java8 dependency can be found on Maven Central.

cucumber-java8依赖性可以在Maven Central上找到。

3. Step Definitions Using Lambda

3.使用Lambda的步骤定义

Next, we will discuss how to write our Step Definitions using Java 8 lambda expressions:

接下来，我们将讨论如何使用Java 8 lambda表达式编写我们的步骤定义。

public class ShoppingStepsDef implements En {

    private int budget = 0;

    public ShoppingStepsDef() {
        Given("I have (\\d+) in my wallet", (Integer money) -> budget = money);

        When("I buy .* with (\\d+)", (Integer price) -> budget -= price);

        Then("I should have (\\d+) in my wallet", (Integer finalBudget) -> 
          assertEquals(budget, finalBudget.intValue()));
    }
}

We used a simple shopping feature as an example:

我们用一个简单的购物功能作为例子。

Given("I have (\\d+) in my wallet", (Integer money) -> budget = money);

Notice how:

注意到如何。

In this step we set the initial budget, we have one parameter money with type Integer
As we are using one statement we didn’t need curly braces

4. Test Scenario

4.测试场景

Finally, let’s take a look at our test scenarios:

最后，让我们来看看我们的测试方案。

Feature: Shopping

    Scenario: Track my budget 
        Given I have 100 in my wallet
        When I buy milk with 10
        Then I should have 90 in my wallet
    
    Scenario: Track my budget 
        Given I have 200 in my wallet
        When I buy rice with 20
        Then I should have 180 in my wallet

And the test configuration:

以及测试配置。

@RunWith(Cucumber.class)
@CucumberOptions(features = { "classpath:features/shopping.feature" })
public class ShoppingIntegrationTest {
    // 
}

For more details on the Cucumber Configuration, check Cucumber and Scenario Outline tutorial.

有关Cucumber配置的更多细节，请查看Cucumber和Scenario Outline 教程。

5. Conclusion

5.结论

We learned how to use Java 8 lambda expressions with Cucumber.

我们学习了如何用Cucumber使用Java 8 lambda表达式。

As always, the full source code is available over on GitHub.

一如既往，完整的源代码可在GitHub上获得，。