data-providers.rst

Data Providers

Data providers let you run the same test with multiple sets of arguments. Any TestCase implementation can have a provider, but currently they are only really first class citizens in the unit test world on Demeanor.

Annotations

Data providers are set on unit tests using the @Provider annotation.

Data providers can be one of three types:

1. A static method on the test class -- @Provider(method="someMethod") or @Provider("someMethod")

2. A function -- @Provider(function="a_provider_function")

3. Inline

   • @Provider(data=["one", "two"])
   • @Provider(data={aKey: ["data", "set"], anotherKey: "dataset"})

Static Method Data Provider

<?php
use Demeanor\TestContext;
use Counterpart\Assert;

class DataProviderMethodTest
{
    public static function aProvider()
    {
        return [
            'one',
            'two',
        ];
    }

    /**
     * These two are the same:
     * @Provider("aProvider")
     * @Provider(method="aProvider")
     */
    public function testWithMethodProvider(TestContext $ctx, $arg)
    {
        Assert::assertType('string', $arg);
    }
}

Function Data Provider

<?php
use Demeanor\TestContext;
use Counterpart\Assert;

function acceptance_dataprovider_function()
{
    return [
        'one',
        'two',
    ];
}

class DataProviderFunctionTest
{
    /**
     * @Provider(function="acceptance_dataprovider_function")
     */
    public function testWithFunctionProvider(TestContext $ctx, $arg)
    {
        Assert::assertType('string', $arg);
    }
}

Inline Data Provider

<?php
use Demeanor\TestContext;
use Counterpart\Assert;

class DataProviderInlineTest
{
    /**
     * @Provider(data=["one", "two"])
     */
    public function testWithDataProviderAsIndexedArray(TestContext $ctx, $arg)
    {
        Assert::assertType('string', $arg);
    }

    /**
     * @Provider(data={aSet: "one", anotherSet: "two"})
     */
    public function testWithDataProviderAsAssociativeArray(TestContext $ctx, $arg)
    {
        Assert::assertType('string', $arg);
    }
}

The Test Context

Notice the the :doc:`test context <test-context>` is always the first argument to test methods. In Demeanor the context object is important, and any data provider arguments will come after it.