What dryrun=true does?

In Cucumber, the dry run feature is a useful option that allows you to check the mapping between feature file steps and step definitions without executing the actual test code. Here’s a detailed explanation of what dry run does and how it works:

What is Dry Run?

• Purpose: The dry run option is used to compile Cucumber feature files and their corresponding step definitions to ensure that every step mentioned in the feature files has a corresponding method defined in the step definition files. It helps identify any missing or incorrectly defined steps without executing the actual test logic.
• Configuration: The dry run option can be set in the @CucumberOptions annotation. It accepts a boolean value:
• dryRun = true: Cucumber will check for the existence of step definitions for all steps in the feature files but will not execute any of the step definitions. This means no browser will open, and no test actions will be performed.
• dryRun = false: Cucumber will execute the tests as usual, running all the code in the step definitions.

How Dry Run Works

1. Compilation Check: When dry run is enabled, Cucumber verifies that all steps in the feature files are linked to corresponding methods in the step definitions. If any step is missing a corresponding method, Cucumber will report it.
2. Execution: With dry run set to true:

• No hooks are executed.
• Steps are reported as “skipped.”
• Undefined and ambiguous steps are reported, but they do not cause the test run to fail.
• The time taken for the run will be minimal since no actual test code is executed.

1. Output: If there are any missing step definitions, Cucumber will provide messages indicating which steps are undefined, allowing you to implement the necessary methods.

Example Usage

Here’s how you might configure a test runner class with the dry run option:

import org.junit.runner.RunWith;
import io.cucumber.junit.Cucumber;
import io.cucumber.junit.CucumberOptions;

@RunWith(Cucumber.class)
@CucumberOptions(
    features = "src/test/resources/features",
    glue = "stepDefinitions",
    dryRun = true // Enable dry run
)
public class TestRunner {
}

Benefits of Using Dry Run

• Quick Validation: It allows developers to quickly validate that their feature files are correctly defined without running the tests, which can save time during the development process.
• Identify Missing Steps: It helps in identifying any missing step definitions early in the development cycle, ensuring that all steps are accounted for before executing the actual tests.
• Improves Test Quality: By ensuring that all steps are properly defined, it contributes to the overall quality and reliability of the test suite.

Conclusion

In summary, the dry run feature in Cucumber is a valuable tool for validating the integrity of feature files and step definitions without executing the tests. By setting dryRun = true, you can quickly check for any missing step definitions and ensure that your tests are correctly set up before running them.