Chapter 17. Skeleton Generator

When you are writing tests for existing code, you have to write the same code fragments such as

public function testMethod()
{
}

over and over again. PHPUnit can help you by analyzing the code of the existing class and generating a skeleton test-case class for it.

Example 17.1: The Calculator class

<?php
class Calculator
{
    public function add($a, $b)
    {
        return $a + $b;
    }
}
?>

The following example shows how to generate a skeleton test class for a class named Calculator (see Example 17.1).

phpunit --skeleton Calculator
PHPUnit 3.2.10 by Sebastian Bergmann.

Wrote test class skeleton for Calculator to CalculatorTest.php.

For each method in the original class, there will be an incomplete test-case (see Chapter 10) in the generated test-case class.

Below is the output of running the generated test-case class.

phpunit --verbose CalculatorTest
PHPUnit 3.2.10 by Sebastian Bergmann.

CalculatorTest
I


Time: 0 seconds

There was 1 incomplete test:

1) testAdd(CalculatorTest)
This test has not been implemented yet.
/home/sb/CalculatorTest.php:54

OK, but incomplete or skipped tests!
Tests: 1, Incomplete: 1.

Annotations

You can use @assert annotation in the documentation block of a method to automatically generate simple, yet meaningful tests instead of incomplete test-cases. Example 17.2 shows an example.

Example 17.2: The Calculator class with @assert annotations

<?php
class Calculator
{
    /**
     * @assert (0, 0) == 0
     * @assert (0, 1) == 1
     * @assert (1, 0) == 1
     * @assert (1, 1) == 2
     */
    public function add($a, $b)
    {
        return $a + $b;
    }
}
?>

Each method in the original class is checked for @assert annotations. These are transformed into test code such as

    /**
     * Generated from @assert (0, 0) == 0.
     */
    public function testAdd() {
        $o = new Calculator;
        $this->assertEquals(0, $o->add(0, 0));
    }

Below is the output of running the generated test-case class.

phpunit CalculatorTest
PHPUnit 3.2.10 by Sebastian Bergmann.

....

Time: 0 seconds


OK (4 tests)

Table 17.1 shows the supported variations of the @assert annotation and how they are transformed into test code.

Table 17.1. Supported variations of the @assert annotation

Annotation	Transformed to
`@assert (...) == X`	`assertEquals(X, method(...))`
`@assert (...) != X`	`assertNotEquals(X, method(...))`
`@assert (...) === X`	`assertSame(X, method(...))`
`@assert (...) !== X`	`assertNotSame(X, method(...))`
`@assert (...) > X`	`assertGreaterThan(X, method(...))`
`@assert (...) >= X`	`assertGreaterThanOrEqual(X, method(...))`
`@assert (...) < X`	`assertLessThan(X, method(...))`
`@assert (...) <= X`	`assertLessThanOrEqual(X, method(...))`
`@assert (...) throws X`	`@expectedException X`