Behavior Driven Development Flashcards
Behavior
- How a product or feature operates. Ex.:
- logging into a webpage
- clicking links in nav bar
- submitting forms
- making successful service calls
- receiving expected errors
What is BDD?
- a test-centric software development process that grew out of Test-Driven Development
- has been around since the mid-2000s
- behaviors become the team’s focus
BDD is a refinement of the Agile process, not an overhaul.
True
Advantages of BDD (part 1):
- Inclusion: anyone can write BDD scenarios
- Clarity: focus on expected behavior of product
- Streamlining: requirements = acceptance criteria = test cases. Expedites automation.
Advantages of BDD (part 2):
- Shift-Left: testing early in the development process, results in fewer bugs later
- Artifacts: scenarios form a collection of test cases. Any tests not automated can be added to a known automation backlog.
- Automation: BDD frameworks make it easy to turn scenarios into automated tests
Advantages of BDD (part 3):
- Test Driven: most BDD frameworks can run scenarios to fail until the feature is implemented
- Code Reuse: “Given-When-Then” steps can be reused between scenarios
- Parametrization: steps can be parametrized
Advantages of BDD (part 4):
- Variation: scenario outlines make it easy to run the same scenario with different combinations of inputs
- Momentum: scenarios become easier and faster to write and automate as more step definitions are added
- Adaptability: scenarios are easy to update as the product changes
What types of tests are BDD best suited for?
- Higher level, functional, black box tests
- E.g., testing APIs and web UIs
What types of tests is BDD NOT well-suited for?
- Overkill for unit tests
- Not good for performance tests, which rely on metrics instead of pass/fail results
Gherkin
domain-specific language for writing BDD scenarios whose language standard is maintained by Cucumber (a prevalent BDD automation framework)
Gherkin scenario structure:
Given-When-Then
Given some initial state, when an action is taken, then verify an outcome
Gherkin Features
- has a title and description - only used for documentation purposes
- associated with user stories
- may have one Background section
- may have multiple associated scenarios and scenario outlines
- should only have one Feature per feature file
Gherkin Scenarios
- each scenario is essentially a test case
- each Given/When/Then line is called a step
- steps MUST appear in the Given/When/Then order
How to write good steps:
Good steps are declarative - states what should happen at a high-level
Not imperative - shouldn’t focus on direct, low-level instructions
In a scenario, each type of step is optional.
True
In a scenario, step order matters.
True
Scenarios are dependent on each other to run.
False. Each scenario runs independently.
Additional steps that can be added to Given, When, or Then:
- And: used instead of repeating G/W/T
- But: functions the same as And, but might be easier to read. Interchangeable with And.
Gherkin: And
- used instead of repeating G/W/T
- example: Given-Given-When-Then = Given-And-When-Then
- associated with the immediately preceding step
- order matters
Gherkin: Background
- a section of Given and And statements to run before each scenario
- does not have a title or description
- only one Background for each Feature section
How do you denote parameter names in Gherkin?
< >
Scenario outlines may have multiple Examples tables.
True
What are Examples?
- a section to provide a table of parameter values for a Scenario Outline
- each table row represents a combination of values to test together
- may have any positive number of rows
Gherkin Keywords: | (pipe character)
- table delimeter used for Examples tables and step tables
- use the escape sequence “|” to use pipe characters as text within a column
Gherkin Keywords: “””
- doc string delimiter for passing large text into a step
- doc strings may be multi-line
Gherkin Keywords: @
- prefix for a tag: @
- tags may be placed before Feature or Scenario sections
- tags are used to filter scenarios
Gherkin Keywords: #
- prefix for a comment line
- comments are not read by the Gherkin parser
How should you phrase Gherkin steps?
Use third person point of view in present tense, and write in complete sentences
Gherkin contains an Or step.
False. Use Scenario Outlines to cover multiple variations of the same behavior.
In pytest-bdd, scenario outlines:
Allow parameterization of scenarios using tables
