PHP code example of ntwalibas / contracts

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

ntwalibas / contracts example snippets

use Contracts\Helpers\Constant;
use function Contracts\Helpers\constx; // As of PHP 5.6+

// PHP 5.5-
// You could as well initialize this object in your class where it will be used
function constx($value)
{
    $constant = new Constant;
    return $constant($value);
}

$age = 17;
$predicate = constx($age)->greaterThan(18);
var_dump($predicate->evaluate());

use Contracts\Helpers\Variable;
use function Contracts\Helpers\varx; // As of PHP 5.6+

// PHP 5.5-
function varx($symbol)
{
    $variable = new Variable;
    return $variable($symbol);
}

$userAges = array(
    "John" => 11, 
    "Marie" => 21, 
    "Paul" => 13, 
    "Dupont" => 42, 
    "Dixit" => 15, 
    "Avinash" => 56, 
    "Bora" => 27
);

$predicate = varx("age")->greaterThan(18);

foreach ($userAges as $name => $age) {
    $predicate->setOperand("age", $age);
    if ($predicate->evaluate() === true) {
        print "$name is a legal adult <br>";
    } else {
        print "$name is a minor <br>";
    }
}

use Contracts\Helpers\Let;
use function Contracts\Helpers\let; // PHP 5.6+

// PHP 5.5-
function let($symbol)
{
    return new Let($symbol)
}

let("age")->be(18);
// Now you can use "age" bellow in predicates and it will have the value of 18

class User
{
    protected $age = 18;

    public function age()
    {
        return $this->age;
    }
}

$user = new User;
let("user")->be($user);

// The age method will be called on the user object
$predicate = varx("user:age")->greaterThan(18);
var_dump($predicate->evaluate());

$user = ["age" => 12];
let("user")->be($user);

// The age key will be access on the user array
$predicate = varx("user:age")->greaterThan(18);
var_dump($predicate->evaluate());

// Booleans
use Contracts\Helpers\Boolean;
use function Contracts\Helpers\boolx;

// Numbers: ints and floats
use Contracts\Helpers\Number;
use function Contracts\Helpers\number;

// Strings
use Contracts\Helpers\StringX;
use function Contracts\Helpers\stringx;

// Arrays
use Contracts\Helpers\ArrayX;
use function Contracts\Helpers\arrayx;

// Objects
use Contracts\Helpers\ObjectX;
use function Contracts\Helpers\objectx;

// Resource
use Contracts\Helpers\ResourceX;
use function Contracts\Helpers\resourcex;

// Callables: not 

use Contracts\Operators;
use Contracts\Predicates\NumberPredicates;
use Contracts\Predicates\StringPredicates;

function varx($symbol)
{
    $predicates = new StringPredicates(new NumberPredicates(new Operators));
    $predicates->setSymbol($symbol);

    return $predicates;
}

$age = 17;
// We do not believe people older than 120 use our product
$predicate = constx($age)->greaterThan(18)->andx()->constx($age)->lessThan(120);
var_dump($predicate->evaluate());

$age = 17;
// We do not believe people older than 120 use our product
$predicate = constx($age)->greaterThan(18)->andx()->lessThan(120);
var_dump($predicate->evaluate());

andx()
orx()
implies()
isEquivalentTo()

$yob = 1990;
$predicate = constx(2015)->minus($yob)->greaterThan(18);

var_dump($predicate->evaluate());

use Contracts\Quantifiers\ForAll;
use function Contracts\Helpers\forAll; // PHP 5.6+

// PHP 5.5-
function forAll($symbol)
{
    return new ForAll($symbol);
}

$userAges = array(   
    [
        "name" => "John",
        "age" => 11
    ],
    [
        "name" => "Marie",
        "age" => 21
    ],
    [
        "name" => "Paul",
        "age" => 13
    ],
    [
        "name" => "Dupont",
        "age" => 42
    ],
    [
        "name" => "Dixit",
        "age" => 15
    ],
    [
        "name" => "Avinash",
        "age" => 56
    ],
    [
        "name" => "Bora",
        "age" => 27
    ]
);

$allAdults =
forAll("user")->in($userAges)->itHoldsThat(
    varx("user:age")->greaterThan(18)
);

var_dump($allAdults->evaluate()); // Return false

use Contracts\Quantifiers\ThereExists;
use Contracts\Helpers\thereExists; // PHP 5.6+

// PHP 5.5-
function thereExists($symbol)
{
    return new ThereExists($symbol);
}

$userAges = array(   
    [
        "name" => "John",
        "age" => 11
    ],
    [
        "name" => "Marie",
        "age" => 21
    ],
    [
        "name" => "Paul",
        "age" => 13
    ],
    [
        "name" => "Dupont",
        "age" => 42
    ],
    [
        "name" => "Dixit",
        "age" => 15
    ],
    [
        "name" => "Avinash",
        "age" => 56
    ],
    [
        "name" => "Bora",
        "age" => 27
    ]
);

$oneAdult =
thereExists("user")->in($userAges)->suchThat(
    varx("user:age")->greaterThan(18)
);

var_dump($oneAdult->evaluate()); // Return true

$set = array(1, 2, 3, 4, 5, 6, 7);

$test =
forAll('x')->in($set)->itHoldsThat(
    thereExists('y')->in($set)->suchThat(
        varx('x')->dividedBy('y')->equalTo(1)
    )
);

var_dump($test->evaluate()); // Will print true

use Contracts\Assertions\Assert;
use Contracts\Assertions\AssertionFailedException;
use function Contracts\Helpers\AssertThat; // PHP 5.6+

// PHP 5.5-
function AssertThat($predicate, $doc)
{
    Assert::That($predicate, $doc);
}

$set = array(1, 2, 3, 4, 5, 6, 7);

try {
    AssertThat(
        forAll('x')->in($set)->itHoldsThat(
            varx('x')->greaterThan(0)->andx()->lessThan("7")
        ),
        "All the numbers must be greater than 0 and less than 7"
    );
} catch (AssertionFailedException $exception) {
    echo $exception->getMessage(); // Will print a message with enough details to know the problem.
    
    // Get the constraints that were provided to the predicates
    $exception->getConstraints($assertionId); // The assertion ID in our case would be "unnamed-assertion" because we did not name the assertion
    
    // Get the operands that we provided to the predicates
    $exception->getOperands($assertionId); 
    
    // Get any possible exceptions throw by either the predicates or quantifiers
    $exception->getExceptions($assertionId);   
}