Unit Test Naming Conventions

Test naming is important for teams on long term project as any other code style conventions. By applying code convention in tests you proclaim that each test name will be readable, understandable and will have a wellknown naming pattern for everyone on the project.

Proper names are poetry in the raw. Like all poetry they are untranslatable. ~W.H. Auden

Before you choose the one naming convention you have to decide first why do you actually need it, what is the purpose of it?

There are few recommendations regarding test naming:

• Test name should express a specific requirement
• Test name could include the expected input or state and the expected result for that input or state
• Test name should be presented as a statement or fact of life that expresses workflows and outputs
• Test name could include the name of the tested method or class

I will present a few examples of existing test naming conventions with:

MethodName_StateUnderTest_ExpectedBehavior

cons: should be renamed if method change name

example: isAdult_AgeLessThan18_False

MethodName_ExpectedBehavior_StateUnderTest

cons: should be renamed if method change name

example: isAdult_False_AgeLessThan18

testFeatureBeingTested

cons: “test” prefix is redundant

example: testIsNotAnAdultIfAgeLessThan18

FeatureToBeTested

cons: no clue what result is expected from name

example: IsNotAnAdultIfAgeLessThan18

Should_ExpectedBehavior_When_StateUnderTest

cons: duplicates `should` and `when`, long name

example: Should_ThrowException_When_AgeLessThan18

When_StateUnderTest_Expect_ExpectedBehavior

cons: duplicates `when` and `expect`

example: When_AgeLessThan18_Expect_isAdultAsFalse

Given_Preconditions_When_StateUnderTest_Then_ExpectedBehavior — Behavior-Driven Development (BDD)

cons: duplicates `given`, `when`, `then`; really long names

example: Given_UserIsAuthenticated_When_InvalidAccountNumberIsUsedToWithdrawMoney_Then_TransactionsWillFail

There are dozens of conventions and it is actually not important which of them you will choose it is important to choose one.