3. Introduction(1/2)
• Cucumber lets software development teams
describe how software should behave in plain
text. The text is written in a business readable
domain specific-language and serves as
documentation, automated tests and
development-aid - all rolled into one format.
• Cucumber works with Ruby, Java, .NET, Flex or
web applications written in any language. It has
been translated to over 40 spoken languages.
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4. Introduction(2/2)
1: Describe behavior in plain text 2: Write a step definition in Ruby 3: Run and watch it fail
4. Write code to make the step pass 5. Run again and see the step pass 6. Repeat 2-5 until green like a cuke
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5. Definition
• Cucumber is a tool that executes plain-text
functional descriptions as automated tests.
The language that Cucumber understands is
called Gherkin
It is a Business Readable, Domain Specific
Language that lets you describe software’s
behavior without detailing how that
behavior is implemented.
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6. Definition
• Cucumber itself is written in Ruby, but it can
be used to “test” code written in Ruby or
other languages including but not limited to
Java, C# and Python.
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7. Gherkin(1/3)
• Gherkin serves two purposes –
documentation and automated tests
• Gherkin’s grammar is defined in the Treetop
grammar that is part of the Cucumber
codebase. The grammar exists in different
flavors for many spoken languages (37 at the
time of writing), so that your team can use the
keywords in your own language.
• Source files have .feature extension.
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8. Gherkin Syntax(2/3)
• Like Python and YAML, Gherkin is a line-
oriented language that uses indentation to
define structure. Line endings terminate
statements (eg, steps).
• Parser divides the input into
features, scenarios and steps. When you run
the feature the trailing portion (after the
keyword) of each step is matched to a Ruby
code block called Step Definitions.
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10. A Gherkin source file usually looks like this
1: Feature: Some terse yet descriptive text of what is desired
2: In order to realize a named business value
3: As an explicit system actor
4: I want to gain some beneficial outcome which furthers the goal
5:
6: Scenario: Some determinable business situation
7: Given some precondition
8: And some other precondition
9: When some action by the actor
10: And some other action
11: And yet another action
12: Then some testable outcome is achieved
13: And something else we can check happens too
14:
15: Scenario: A different situation
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11. • First line starts the feature.
• Lines 2-4 are unparsed text, which is expected
to describe the business value of this feature.
Line 6 starts a scenario.
• Lines 7-13 are the steps for the scenario.
• Line 15 starts next scenario and so on.
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12. .Feature
• The scenario is then divided into three parts.
1. The ‘Given’ part describes how the system
should be prepared before the testing. This is
the setup for the system.
2. The ‘When’ part describes how the system
should be used. This is the execution part of the
example.
3. The ‘Then’ part is where you verify that the
system is in the expected state. This is the assert
part of the test.
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13. TDD & BDD
• Test driven development
The word “driven” here refers to the way of writing the
tests first, then the code to make the tests pass. Test
driven development is more of a developer oriented
approach, a more low level way of doing things.
• Behaviour driven development
In BDD on the other hand, the tests are described in a
natural language, which makes the tests more accessible
to people outside of development or testing teams. It can
describe the functionality as specifications do.
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14. Cucumber and BDD
• While Cucumber can be thought of as a
“testing” tool, the intent of the tool is to
support BDD. This means that the “tests”
(plain text feature descriptions with scenarios)
are typically written before anything else and
verified by business analysts, domain
experts, etc. non technical stakeholders. The
production code is then written outside-in, to
make the stories pass.
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15. Installation(1/2)
• In order to use Cucumber within some
frameworks or specific environments :
• install for Ruby on Rails
• install for Jruby and Java
• install for IronRuby and .NET
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16. Installation(2/2)
Cucumber-jvm
JUnit class that will connect the feature to a runner,
Cucumber-html.jar
Jchronic.jar
Cucumber-core.jar Cucumber-java.jar
Cucumber-junit.jar
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17. Running Cucumber
• There are quite a few ways you can run
Cucumber. It depends on what programming
language you are using and also what build tool
you are using (if any).
• Command Line
• Rake
• Maven
• Ant
• JUnit
• IDEs (Eclipse, IDEA)
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