How to use data providers to run parameterized tests in PHPUnit?

In order to run parameterized tests using data providers in PHPUnit, you need to follow these steps:

Create your test case class extending the PHPUnit\Framework\TestCase class.
Define a public static method that returns an array of test data. This method will act as a data provider for your tests. Each element of the array represents a single set of test data.
Annotate your test method with the @dataProvider annotation, specifying the name of the data provider method as its parameter. This will instruct PHPUnit to use the data provider method to generate the test data for the test method.
In your test method, declare parameters that match the structure of the data elements returned by the data provider method.
Write your test logic, using the parameters declared in the previous step.

Here's an example to illustrate the process:

class MyTestCase extends \PHPUnit\Framework\TestCase
{
    public static function dataProviderMethod()
    {
        return [
            [1, 2, 3],    // Test case 1
            [4, 5, 9],    // Test case 2
            [10, 15, 25], // Test case 3
        ];
    }

    /**
     * @dataProvider dataProviderMethod
     */
    public function testAddition($a, $b, $expected)
    {
        $result = $a + $b;
        $this->assertEquals($expected, $result);
    }
}

In the example above, the dataProviderMethod acts as a data provider for the testAddition method. The testAddition method has three parameters that match the structure of the data elements ($a, $b, and $expected). PHPUnit will execute the testAddition method three times, once for each set of test data returned by the data provider method.

Note that you can have multiple data provider methods in your test case class, and use different data providers for different test methods. Additionally, you can use external data sources like CSV files or databases as data providers by implementing a custom data provider method.

By using data providers, you can easily run your tests with different input values without duplicating test code, making it more efficient and maintainable.