Tests for new Null Coalescing assignment Operator

null-coalescing-assignment-test.php

<?php

class Test extends PHPUnit_Framework_TestCase
{
    
    // https://www.reddit.com/r/ruby/comments/l2y8m/rubyists_already_use_monadic_patterns/c2pjlt8
    public function testPHPImplementation(){
        $a ?? $a = 5;
        $this->assertTrue($a == 5);
        $a ?? $a = 9;
        $this->assertTrue($a == 5);
    }
    
    public function testRubyImplementation(){
        $a || $a = 5;
        $this->assertTrue($a == 5);
        $a || $a = 9;
        $this->assertTrue($a == 5);
    }
    
	public function testOne() {
        $a = null;
        $b = 20;
        $a ??= $b;
		$this->assertTrue($a == 20);
  	}
    
	public function testSecond() {
        $array['key'] ??= 10;
        $array['key'] ??= 10;
		$this->assertTrue($array['key'] == 10);
  	}
    
	public function testThird() {
        $array['key'] = $array['key'] ?? 10;
        $array['key'] = $array['key'] ?? 20;
		$this->assertTrue($array['key'] == 10);
  	}
    
	public function testFourth() {
        $array['key'] = $array['key'] ?? 10;
        $array['key'] = $array['key'] ?? 20;
		$this->assertTrue($array['key'] == 10);
  	}
    
    public function testFifth(){
        $object = new Class{
            
            __set($name, $value){
                $this->$name = $value;
                echo "Setting ".$name." to ".$this->$name;
            }
        }
        
        $object->val ??= 'a';
        $object->val ??= 'b';
        
        $this->assertTrue($object == 'a');
    }
    
    public function testSixth(){
        $object = new Class implements ArrayAccess{
            
            public function __construct() {
                $this->container = array(
                    "one"   => 1,
                    "two"   => 2,
                    "three" => 3,
                );
            }

            public function offsetSet($offset, $value) {
                if (is_null($offset)) {
                    $this->container[] = $value;
                } else {
                    $this->container[$offset] = $value;
                }
            }

            public function offsetExists($offset) {
                return isset($this->container[$offset]);
            }

            public function offsetUnset($offset) {
                unset($this->container[$offset]);
            }

            public function offsetGet($offset) {
                return isset($this->container[$offset]) ? $this->container[$offset] : 'default';
            }
        }
        
        $object['key'] ??= 'a';
        $this->assertTrue($object['key'] == null);
        
        $object['key'] = $object['key'] ?? 'a';
        $this->assertTrue($object['key'] == 'default');
    }
    
    public function testSeventh(){
         $a[0][1][0] = 5;
         $this->assertTrue($a[0][1][0] == 5);
         
         $a[0][1][1] = $a[0][1][1] ?? 5;
         $this->assertTrue($a[0][1][1] == 5);
         
         $a[0][1][1] ??= 5;
         $this->assertTrue($a[0][1][1] == 5);
    }
}

?>