Building DSLs

dsl.php

<?php

function describe($testedClass, callable $tests) {
    print ("$testedClass" . PHP_EOL);
    $tests();
}

function it($testName, callable $test) {
    print("    $test" . PHP_EOL);
    $test();
}

// because the last argument is a callable we can now:

describe ("BankAccount") {
    it ("starts with a zero amount") {
        $amount = (new BankAccount())->getAmount();
        if ($amount !== 0) throw new Failure("Expected 0, got $amount");
    }
}