Sentence Style For Naming Unit Tests

A method of naming UnitTests that allows the test class to be read as descriptive documentation of the class under test. Invented by ChrisStevenson.

A unit test class is named after the class under test. E.g. a test for the Sheep class would be called SheepTest or SheepTests.

The methods of the test class are named to complete a sentence that begins with "A class-under-test...". E.g. the methods of SheepTest would be named to continue the sentence "A Sheep...".

For example, in Java:

public class SheepTest {
        @Test public void eatsGrass() { ... }
        @Test public void bleatsWhenFrightened() { ... }
        @Test public void producesDeliciousMilk() { ... }
        @Test public void movesAwayFromSheepdogs() { ... }
}

This can be read as:

• A Sheep eats grass
• A Sheep bleats when frightened
• A Sheep produces delicious milk
• A Sheep moves away from sheepdogs

There are tools that generate documentation from tests written with this convention. For example, TestDox?

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More expressive languages do not need this convention, because tests can be implemented as blocks associated with string descriptions of what is being tested.