Platform.sh

PHP 7[.2]

The New New PHP

Presented by Larry Garfield (@Crell)

@Crell

Director of DX, Platform.sh
PHP-FIG Core Committee
implements Huggable

Show me the data!

(Credit: https://seld.be/notes/php-versions-stats-2018-1-edition)

You're missing

(Credit: https://seld.be/notes/php-versions-stats-2018-1-edition)

#1

Do you trust your docblock?


class User {
  protected $id;
  protected $address;

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

function compute_shipping($src, User $user) {
  $dest = $user->getAddress();

  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}


class User {
  protected $id;
  protected $address;

  /**
   * @return Address
   */
  public function getAddress() {
    return $this->address;
  }
}

function compute_shipping($src, User $user) {
  $dest = $user->getAddress();

  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}


class User {
  protected $id;
  protected $address;

  public function getAddress() : Address {
    return $this->address;
  }
}

function compute_shipping($src, User $user) {
  $dest = $user->getAddress();

  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}

Return types

New in PHP 7!
Not nullable until 7.1


$r = new UserRepository();

print $r->findById(123)->getAddress()->getStreet() . PHP_EOL;


          Method called on non-object

No NULL means:

Exception
"Empty" value object

For Repositories etc.


class UserRepository {
  // ...

  public function findById($id) : User {
    if (/* can't find the user */) {
     throw new InvalidArgumentException('No such User: ' . $id);
    }
    return $user;
  }

}

For Value objects


interface AddressInterface {
  public function getStreet();
  public function getCity();
  public function getState();
  public function getZip();
}

class EmptyAddress implements AddressInterface {
  public function getStreet() { return ''; }
  public function getCity() { return ''; }
  public function getState() { return ''; }
  public function getZip() { return ''; }
}

class Address implements AddressInterface {
    // ...
}

Returning false on error is a
big 'screw you' to your users

But in 7.1...


class UserRepository {
  // ...

  public function findById($id) : ?User {
    if (/* can't find the user */) {
     return null;
    }
    return $user;
  }

}

(Please don't)

`void` returns


function return_to_sender() : void {
  // Do stuff
  // ...
  return;      // Legal
  return null; // Not OK
  return 1;    // Not even a little OK
}

#2


function compute_shipping($src, AddressInterface $dest) {
  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}

function distance_between(AddressInterface $src, AddressInterface $dest) {
  // ...
}

$u_address = new Address(); // ...
$user = new User(123, $u_address);

$src = new Address(); // ...
compute_shipping($src, $user->getAddress());

What does distance_between() return?


function compute_shipping(AddressInterface $src, AddressInterface $dest) : float {
  $distance = distance_between($src, $dest);

  return $distance * .5; // 50 cents/mile
}

function distance_between(AddressInterface $src, AddressInterface $dest) : int {
  // ...
}

$u_address = new Address(); // ...
$user = new User(123, $u_address);

$src = new Address(); // ...
compute_shipping($src, $user->getAddress());

Everyone here owes
Andrea Faulds and Anthony Ferrara a drink

New type specs in PHP 7

int
float
string
bool

Full type list

int
float
string
bool
array
callable
object
Any class name


interface AddressInterface {
  public function getStreet();
  public function getCity();
  public function getState();
  public function getZip();
}

Is getStreet() a string or object?


interface AddressInterface {
  public function getStreet() : string;
  public function getCity() : string;
  public function getState() : string;
  public function getZip() : string;
}


class Address implements AddressInterface {
  public function __construct(string $street, string $city, string $state, string $zip) {
    // ...
  }
  // ...
}


$u_address = new Address('45 Hull St', 'Boston', 'MA', 02215);
$user = new User(123, $u_address);

$src = new Address('1060 W Addison St', 'Chicago', 'IL', 60613);
compute_shipping($src, $user->getAddress());

Strict vs Weak mode

Weak by default

* string -> int may E_NOTICE

Strict mode

Address.php


declare(strict_types=1);

class Address implements AddressInterface {
  public function __construct(string $street, string $city, string $state, string $zip) {
    // ...
  }
  public function getZip() : string {
    return $this->zip;
  }

  // ...
}

Affects calls and returns from this file

Strict mode

setup.php


declare(strict_types=1);

$u_address = new Address('4 Yawkey Way', 'Boston', 'MA', 02215);
$user = new User(123, $u_address);

$src = new Address('1060 W Addison St', 'Chicago', 'IL', 60613);
compute_shipping($src, $user->getAddress());

Affects calls and returns from this file

Casting in strict mode

* int converts to float automatically

Using strict types

90% of the time

(Everywhere except Input)

Also, Documentation

BC Warning!

New reserved words!

#3


usort($array, function ($a, $b) {
  if ($a < $b) {
    return -1;
  }
  elseif ($a > $b) {
    return 1;
  }
  else {
    return 0;
  }
});

T_SPACESHIP

<=>


usort ($array, function($a, $b) {
  return $a <=> $b;
});


usort($people, function (Person $a, Person $b) {
  if ($a->lastName() < $b->lastName()) {
    return -1;
  }
  elseif ($a->lastName() > $b->lastName()) {
    return 1;
  }
  else {
    if ($a->firstName() < $b->firstName()) {
      return -1;
    }
    elseif ($a->firstName() > $b->firstName()) {
      return 1;
    }
    else {
      return 0;
    }
  }
});


usort($people, function (Person $a, Person $b) {
  return $a->lastName() < $b->lastName() ? -1
    : ($a->lastName() > $b->lastName() ? 1
      : $a->firstName() < $b->firstName() ? -1
        : ($a->firstName() > $b->firstName() ? 1 : 0));
});

You're Fired!


usort($people, function (Person $a, Person $b) {
 return [$a->lastName(), $a->firstName()] <=> [$b->lastName(), $b->firstName()];
});

#4


$username = $username ? $username : 'Anonymous';


$username = $username ?: 'Anonymous';

But what if $username doesn't exist?


Notice: Undefined variable: username on line 3


$username = isset($username) && !is_null($username) ? $username : 'Anonymous';

NULL coalesce!


$username = $username ?? 'Anonymous';


$username = $submitted['username'] ?? $user->username() ?? 'Anonymous';

?? checks setness, not truthiness

#5

Cryptography is hard

Don't we have this already?

rand() isn't really random
mcrypt() isn't really random (also unsupported)
fread(fopen('/dev/urandom'), 16) isn't portable
openssl is hard to use

What we want is an easy
Cryptographically Secure Pseudo-Random Number Generator

CSPRNG!

Ask and ye shall receive…


$junk = random_bytes(16);

$val = random_int(1, 100);

On PHP 5?

composer require paragonie/random_compat

https://github.com/paragonie/random_compat

If you're not using these functions for security...

password_hash() / password_verify()
random_bytes()
random_int()

You're Doing It Wrong!

BC Warning!

Reserved function names

random_bytes()
random_int()

#6

Mocking is hard


$mock_repository = $this
  ->getMockBuilder(ThingieRepository::class)
  ->disableOriginalConstructor()
  ->getMock();

$obj1 = new Thingie();
$obj1->setVal('abc');

$obj2 = $this->getMockBuilder(Thingie::class)
  ->disableOriginalConstructor()
  ->getMock();
$obj1 ->method('getVal')->willReturn('def');

$map = [ [1, $obj1], [2, $obj2] ];

$mock_repository
  ->method('load')->will($this->returnValueMap($map));

$subject = new ClassUnderTest($mock_repository);
$this->assertTrue($subject->findThings());

Fakes are easy


$fake_repository = new class extends ThingieRepository {
  public function __construct() {}

  public function load($id) {
    switch ($id) {
      case 1:
        $obj1 = new Thingie();
        $obj1->setVal('abc');
        return $obj1;
      case 2:
        return new class extends Thingie {
          public function getVal() {
            return 'def';
          }
        };
    }
  }
};

$subject = new ClassUnderTest($fake_repository);
$this->assertTrue($subject->findThings());

One-off dependencies


new Service(new class implements LoggerInterface {
  use LoggerTrait;

  public function log($message) {
    print $message . PHP_EOL;
  }
});

Constructors, too


new class($logger) implements ServiceInterface {
  public function __construct(LoggerInterface $logger) {
    $this->logger = $logger;
  }

  public function doServiceStuff() { }
};

#7

Fatal errors suck

Recoverable errors… aren't

PHP 5


function doStuff(Request $r) {
  // ...
}

$u = new User();

doStuff($u);

Catchable fatal error: Argument 1 passed to doStuff() must be an instance of Request, instance of User given

PHP 7


function doStuff(Request $r) {
  // ...
}

$u = new User();

try {
  doStuff($u);
}
catch (\TypeError $e) {
  print "Wrong variable type, dummy." . PHP_EOL;
}


try {
  include 'buggy_file.php';
}
catch (\ParseError $e) {
  $logger->error("That file is buggy!");
}


try {
  nonexistant_function();
}
catch (\Error $e) {
  print "The error was " . $e->getMessage();
}

Throwable is at the root of all Errors and Exceptions

E_FATAL, E_RECOVERABLE_ERROR, E_PARSE, E_COMPILE_ERROR

Exceptions: The user screwed up

Errors: The coder screwed up

BC Warning!

New reserved class names

Global exception handler

PHP 5


set_exception_handler(function(\Exception $e) {
  // ...
});

PHP 7


set_exception_handler(function(\Throwable $e) {
  // ...
});

PHP 5 & 7


set_exception_handler(function($e) {
  // ...
});

#8

Assertions suck


function doStuff(array $def) {
  assert(isset($def['key']) && isset($def['value']), 'Invalid def');
  // ...
}


function doStuff(array $def) {
  assert('isset($def[\'key\']) && isset($def[\'value\'])', 'Invalid def');
  // ...
}

PHP 7: Expectations


ini_set('assert.exception', 1);
ini_set('zend.assertions', 1);

class InvalidDef extends AssertionError {}

function doStuff(array $def) {
  assert(isset($def['key']) && isset($def['value']), new InvalidDef('Invalid def'));
  // ...
}

Assertions are actually not-broken!

#9

`Iterate` this!

PSR-8 FTW!


function hug_friends(array $friends) {
  foreach ($friends as $friend) {
    hug($friend);
  }
}


function hug_friends(\Traversable $friends) {
  foreach ($friends as $friend) {
    hug($friend);
  }
}

There can be only one!

Your friends are sad :-(


/**
 * @param array|\Traversable $friends
 */
function hug_friends($friends) {
  foreach ($friends as $friend) {
    hug($friend);
  }
}

PHP 7.1 makes friends happy


function hug_friends(iterable $friends) : iterable {
  foreach ($friends as $friend) {
    hug($friend);
  }
  return $friends;
}


is_iterable([1, 2, 3]); // true
is_iterable(new ArrayIterator([1, 2, 3])); // true
is_iterable((function () { yield 1; })()); // true
is_iterable(1); // false
is_iterable(new stdClass()); // false

iterable => foreach()-able

#10

What does this do?


$$foo['bar']['baz']


$foo->$bar['baz']


$foo->$bar['baz']()


Foo::$bar['baz']()


Foo::$bar[1][2][3]()

Uniform variable syntax

Always Left-To-Right

It's logical


$foo()['bar']()
[$obj1, $obj2][0]->prop
getStr(){0}
$foo['bar']::$baz
$foo->bar()::baz()
$foo()()


(...)['foo']
(...)->foo
(...)->foo()
(...)()

(function() { ... })()
($obj->closure)()

BC Break

Complex cases change meaning

When in doubt, use () or {}

(Credit: https://www.flickr.com/photos/martin_heigan/4544138976/)

Credit: Rasmus Lerdorf

But I have legacy code!

You have tests, right...?

Tooling to the rescue

Get https://github.com/squizlabs/PHP_CodeSniffer
Get https://github.com/wimg/PHPCompatibility
vendor/bin/phpcs --standard=PHPCompatibility .
Buy Wim Goden (@wimgtr) a $beverage
Profit!1!eleven!

oldAndBusted.php


function random_int()
{
    return rand();
}

class Error {}

$a = [1, 2, 3];
$b = ['a', 'b', 'c'];

print $$b[1];

composer.json


{
    "require-dev": {
        "squizlabs/php_codesniffer": "^2.2 || ^3.0.2",
        "wimg/php-compatibility": "*",
        "DealerDirect/phpcodesniffer-composer-installer": "^0.4.3"
    },
    "prefer-stable" : true
}

Profit


$ vendor/bin/phpcs --standard=PHPCompatibility oldAndBusted.php

FILE: /home/crell/temp/phptest/oldAndBusted.php
---------------------------------------------------------------------------------------
FOUND 1 ERROR AFFECTING 1 LINE
---------------------------------------------------------------------------------------
 11 | ERROR | Indirect access to variables, properties and methods will be evaluated
    |       | strictly in left-to-right order since PHP 7.0. Use curly braces to
    |       | remove ambiguity.
---------------------------------------------------------------------------------------

Time: 60ms; Memory: 6Mb

Caveats

Large directories can be slow
Can only test up to the installed version
Static analysis can't catch everything

Tools can do 80% of the work

The market is already there

http://phpversions.info/

PHP 7.2-ready hosts: 22 and counting

(Yes, Platform.sh is one of them!)

Require PHP 7.1.x

Require PHP 7.0.x

Time is running out...

PHP 7.0 and earlier lose all support this year.

Larry Garfield

Director of Developer Experience, Platform.sh

Continuous Deployment Cloud Hosting

Stalk us at @PlatformSH

Thanks to Palantir.net for helping develop these slides

PHP 7[.2]

The New New PHP

@Crell

Show me the data!

You're missing

#1

Return types

For Repositories etc.

For Value objects

But in 7.1...

void returns

#2

New type specs in PHP 7

Full type list

Strict vs Weak mode

Strict mode

Strict mode

Casting in strict mode

Using strict types

BC Warning!

#3

T_SPACESHIP

<=>

#4

#5

Don't we have this already?

On PHP 5?

BC Warning!

#6

Mocking is hard

Fakes are easy

One-off dependencies

Constructors, too

#7

PHP 5

PHP 7

BC Warning!

PHP 5

PHP 7

PHP 5 & 7

#8

PHP 7: Expectations

#9

Iterate this!

PSR-8 FTW!

Your friends are sad :-(

PHP 7.1 makes friends happy

#10

What does this do?

Uniform variable syntax

It's logical

BC Break

Tooling to the rescue

Caveats

The market is already there

Require PHP 7.1.x

Require PHP 7.0.x

Time is running out...

Larry Garfield

`void` returns

`Iterate` this!