EnvironmentVariables.md

Managing Environment Variables

In situations where apps behave differently based on environment variables (e.g. getenv() and putenv()), the EnvironmentVariables trait creates fixtures to manipulate these variables while resetting them between tests.

Methods

setEnvironmentVariable()

Set or update an environment variable for the duration of the test.

setEnvironmentVariable(string $key[, mixed $value = null]): self

This is a wrapper around PHP's putenv() function.

Parameters

$key

The environment variable name.

$value

The value to set for the environment variable. Default is null

Passing NULL to $value will remove the environment variable.

Return values

This method will return the calling class, enabling multiple methods to be chained.

---

deleteEnvironmentVariable()

Delete/unset an environment variable for a single test.

deleteEnvironmentVariable(string $key): bool

This is equivalent to calling $this->setEnvironmentVariable($key, null).

Parameters

$key

The environment variable name.

Return values

This method will return the calling class, enabling multiple methods to be chained.

Examples

Setting an environment variable in a test

Imagine we have a function, greet_user(), which tries to read the user's name from the username environment variable:

use AssertWell\PHPUnitGlobalState\EnvironmentVariables;
use PHPUnit\Framework\TestCase;

class MyTestClass extends TestCase
{
    use EnvironmentVariables;

    /**
     * @test
     */
    public function greetings_should_include_the_username_env_var()
    {
        $this->setEnvironmentVariable('username', 'Test McTest');

        $this->assertSame('Hello, Test McTest!', greet_user());
    }
}

Regardless of whether or not greetings_should_include_the_username_env_var() passes, the username environment variable will be reset after the test method completes.