psalm/tests/PureAnnotationTest.php

<?php
namespace Psalm\Tests;

use const DIRECTORY_SEPARATOR;

class PureAnnotationTest extends TestCase
{
    use Traits\InvalidCodeAnalysisTestTrait;
    use Traits\ValidCodeAnalysisTestTrait;

    /**
     * @return iterable<string,array{string,assertions?:array<string,string>,error_levels?:string[]}>
     */
    public function providerValidCodeParse()
    {
        return [
            'simplePureFunction' => [
                '<?php
                    namespace Bar;

                    class A {
                        public int $a = 5;
                    }

                    /** @psalm-pure */
                    function filterOdd(int $i, A $a) : ?int {
                        if ($i % 2 === 0 || $a->a === 2) {
                            return $i;
                        }

                        $a = new A();

                        return null;
                    }',
            ],
            'pureFunctionCallingBuiltinFunctions' => [
                '<?php
                    namespace Bar;

                    /** @psalm-pure */
                    function lower(string $s) : string {
                        return substr(strtolower($s), 0, 10);
                    }',
            ],
            'pureWithStrReplace' => [
                '<?php
                    /** @psalm-pure */
                    function highlight(string $needle, string $output) : string {
                        $needle = preg_quote($needle, \'#\');
                        $needles = str_replace([\'"\', \' \'], [\'\', \'|\'], $needle);
                        $output = preg_replace("#({$needles})#im", "<mark>$1</mark>", $output);

                        return $output;
                    }'
            ],
            'implicitAnnotations' => [
                '<?php
                    abstract class Foo {
                        private array $options;
                        private array $defaultOptions;

                        function __construct(array $options) {
                            $this->setOptions($options);
                            $this->setDefaultOptions($this->getOptions());
                        }

                        function getOptions(): array {
                            return $this->options;
                        }

                        function setOptions(array $options): void {
                            $this->options = $options;
                        }

                        function setDefaultOptions(array $defaultOptions): void {
                            $this->defaultOptions = $defaultOptions;
                        }
                    }',
            ],
            'canCreateObjectWithNoExternalMutations' => [
                '<?php
                    /** @psalm-external-mutation-free */
                    class Counter {
                        private int $count = 0;

                        public function __construct(int $count) {
                            $this->count = $count;
                        }

                        public function increment() : void {
                            $this->count++;
                        }

                        public function incrementByTwo() : void {
                            $this->count = $this->count + 2;
                        }

                        public function incrementByFive() : void {
                            $this->count += 5;
                        }
                    }

                    /** @psalm-pure */
                    function makesACounter(int $i) : Counter {
                        $c = new Counter($i);
                        $c->increment();
                        $c->incrementByTwo();
                        $c->incrementByFive();
                        return $c;
                    }',
            ],
            'canCreateImmutableObject' => [
                '<?php
                    /** @psalm-immutable */
                    class A {
                        private string $s;

                        public function __construct(string $s) {
                            $this->s = $s;
                        }

                        public function getShort() : string {
                            return substr($this->s, 0, 5);
                        }
                    }

                    /** @psalm-pure */
                    function makeA(string $s) : A {
                        $a = new A($s);

                        if ($a->getShort() === "bar") {
                            return new A("foo");
                        }

                        return $a;
                    }'
            ],
            'assertIsPureInProductionn' => [
                '<?php
                    /**
                     * @psalm-pure
                     */
                    function toDateTime(?DateTime $dateTime) : DateTime {
                        assert($dateTime instanceof DateTime);
                        return $dateTime;
                    }'
            ],
            'allowArrayMapClosure' => [
                '<?php
                    /**
                     * @psalm-pure
                     * @param string[] $arr
                     */
                    function foo(array $arr) : array {
                        return \array_map(function(string $s) { return $s;}, $arr);
                    }'
            ],
            'pureBuiltinCall' => [
                '<?php
                    final class Date
                    {
                        /** @psalm-pure */
                        public static function timeZone(string $tzString) : DateTimeZone
                        {
                            return new \DateTimeZone($tzString);
                        }
                    }',
            ],
        ];
    }

    /**
     * @return iterable<string,array{string,error_message:string,2?:string[],3?:bool,4?:string}>
     */
    public function providerInvalidCodeParse()
    {
        return [
            'impurePropertyAssignment' => [
                '<?php
                    namespace Bar;

                    class A {
                        public int $a = 5;
                    }

                    /** @psalm-pure */
                    function filterOdd(int $i, A $a) : ?int {
                        $a->a++;

                        if ($i % 2 === 0 || $a->a === 2) {
                            return $i;
                        }

                        return null;
                    }',
                'error_message' => 'ImpurePropertyAssignment',
            ],
            'impureMethodCall' => [
                '<?php
                    namespace Bar;

                    class A {
                        public int $a = 5;

                        public function foo() : void {
                            $this->a++;
                        }
                    }

                    /** @psalm-pure */
                    function filterOdd(int $i, A $a) : ?int {
                        $a->foo();

                        if ($i % 2 === 0 || $a->a === 2) {
                            return $i;
                        }

                        return null;
                    }',
                'error_message' => 'ImpureMethodCall',
            ],
            'impureFunctionCall' => [
                '<?php
                    namespace Bar;

                    function impure() : ?string {
                        /** @var int */
                        static $i = 0;

                        ++$i;

                        return $i % 2 ? "hello" : null;
                    }

                    /** @psalm-pure */
                    function filterOdd(array $a) : void {
                        impure();
                    }',
                'error_message' => 'ImpureFunctionCall',
            ],
            'impureConstructorCall' => [
                '<?php
                    namespace Bar;

                    class A {
                        public int $a = 5;
                    }

                    class B {
                        public function __construct(A $a) {
                            $a->a++;
                        }
                    }

                    /** @psalm-pure */
                    function filterOdd(int $i, A $a) : ?int {
                        $b = new B($a);

                        if ($i % 2 === 0 || $a->a === 2) {
                            return $i;
                        }

                        return null;
                    }',
                'error_message' => 'ImpureMethodCall',
            ],
            'canCreateObjectWithNoExternalMutations' => [
                '<?php
                    class Counter {
                        private int $count = 0;

                        public function __construct(int $count) {
                            $this->count = $count;
                        }

                        public function increment() : void {
                            $this->count += rand(0, 5);
                        }
                    }

                    /** @psalm-pure */
                    function makesACounter(int $i) : Counter {
                        $c = new Counter($i);
                        $c->increment();
                        return $c;
                    }',
                'error_message' => 'ImpureMethodCall',
            ],
            'useOfStaticMakesFunctionImpure' => [
                '<?php
                    /** @psalm-pure */
                    function addCumulative(int $left) : int {
                        /** @var int */
                        static $i = 0;
                        $i += $left;
                        return $left;
                    }',
                'error_message' => 'ImpureStaticVariable',
            ],
            'preventImpureArrayMapClosure' => [
                '<?php
                    /**
                     * @psalm-pure
                     * @param string[] $arr
                     */
                    function foo(array $arr) : array {
                        return \array_map(function(string $s) { return $s . rand(0, 1);}, $arr);
                    }',
                'error_message' => 'ImpureFunctionCall',
            ],
        ];
    }
}