Overview
In Cucumber, Background steps are a series of steps that are run before each scenario within a Feature. They are used to set up a common context for all scenarios in the feature file. This is particularly useful for reducing duplication of steps in each scenario that require the same initial setup.
Key Concepts
- DRY Principle: Background steps help keep the feature files clean and adhere to the "Don't Repeat Yourself" principle by allowing you to specify common steps once for multiple scenarios.
- Test Setup: They are crucial for setting up the preconditions for your tests, ensuring that each scenario starts from a common state.
- Readability and Maintenance: Background steps improve the readability of feature files and make them easier to maintain by centralizing common setup steps.
Common Interview Questions
Basic Level
- What is the purpose of Background steps in Cucumber?
- How do you define Background steps in a Cucumber feature file?
Intermediate Level
- How do Background steps affect the execution of scenarios in a feature file?
Advanced Level
- Discuss a scenario where using Background steps might not be the best approach.
Detailed Answers
1. What is the purpose of Background steps in Cucumber?
Answer: The purpose of Background steps in Cucumber is to provide a way to specify a set of steps that are common to all scenarios in a feature file, ensuring that each scenario starts with the same context or preconditions. This helps in reducing redundancy and making the feature files more readable and maintainable.
Key Points:
- Reduces duplication of steps across scenarios
- Ensures a common starting point for all scenarios
- Improves the readability and maintainability of feature files
Example:
// There's no direct C# example for writing Cucumber Background steps as they are defined in the Gherkin language within a .feature file. However, the concept can be understood with a Gherkin example:
/*
Feature: User login
Background: User is on the login page
Given the user is on the login page
Scenario: Successful login
When the user enters valid credentials
Then the user is redirected to the dashboard
Scenario: Unsuccessful login
When the user enters invalid credentials
Then the user sees an error message
*/
2. How do you define Background steps in a Cucumber feature file?
Answer: Background steps are defined in a Cucumber feature file using the Background: keyword followed by a series of Given, When, or Then steps that outline the common setup actions. These steps are executed before each scenario in the feature file.
Key Points:
- Defined using the Background: keyword
- Can include any type of step (Given, When, Then)
- Executed before each scenario in the feature file
Example:
// Again, as Background steps are part of Gherkin syntax, the example will be in Gherkin:
/*
Feature: User profile updates
Background: User is logged in and on the profile page
Given the user is logged in
And the user navigates to the profile page
Scenario: Update user profile picture
When the user uploads a new profile picture
Then the profile picture is updated
Scenario: Update user bio
When the user updates the bio information
Then the bio information is updated
*/
3. How do Background steps affect the execution of scenarios in a feature file?
Answer: Background steps are run before each scenario in the feature file, setting up the necessary preconditions for the tests. This ensures that despite the different actions and assertions in each scenario, they all start from a common state defined by the Background steps.
Key Points:
- Background steps are executed before each scenario.
- They ensure a consistent starting state for all scenarios.
- They do not affect the order of execution of the scenarios but serve as a preparatory step.
Example:
// Example illustrating the conceptual flow, not specific C# code:
/*
Assuming a feature file with a Background section and two scenarios:
Background: User is on the home page
Given the user is on the home page
Scenario 1: User navigates to profile
...
Scenario 2: User logs out
...
The execution flow:
1. Execute Background steps
2. Execute Scenario 1 steps
3. Execute Background steps (again)
4. Execute Scenario 2 steps
*/
4. Discuss a scenario where using Background steps might not be the best approach.
Answer: While Background steps are useful for setting up a common context, they might not be the best approach when scenarios in a feature file require significantly different initial setups. Overusing Background for diverse scenarios can lead to confusion and make the scenarios less readable by obfuscating necessary context setup within the Background.
Key Points:
- Not suitable for scenarios with divergent preconditions.
- Can reduce readability if overused or used inappropriately.
- May lead to confusing test outcomes if the common setup is not applicable to all scenarios.
Example:
// Conceptual explanation, specific examples would depend on the context:
/*
If a feature file contains scenarios that start from completely different application states, it might be clearer to define the necessary setup steps within each scenario rather than using a Background section. This ensures that the setup for each scenario is immediately visible and understandable to someone reading the test.
*/
