psalm/tests/RedundantConditionTest.php

<?php
namespace Psalm\Tests;

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

    /**
     * @return iterable<string,array{string,assertions?:array<string,string>,error_levels?:string[]}>
     */
    public function providerValidCodeParse()
    {
        return [
            'ignoreIssueAndAssign' => [
                '<?php
                    function foo(): stdClass {
                        return new stdClass;
                    }

                    $b = null;

                    foreach ([0, 1] as $i) {
                        $a = foo();

                        if (!empty($a)) {
                            $b = $a;
                        }
                    }',
                'assertions' => [
                    '$b' => 'null|stdClass',
                ],
                'error_levels' => ['RedundantCondition'],
            ],
            'byrefNoRedundantCondition' => [
                '<?php
                    /**
                     * @param int $min ref
                     * @param int $other
                     */
                    function testmin(&$min, int $other): void {
                        if (is_null($min)) {
                            $min = 3;
                        } elseif (!is_int($min)) {
                            $min = 5;
                        } elseif ($min < $other) {
                            $min = $other;
                        }
                    }',
                'assertions' => [],
                'error_levels' => [
                    'RedundantConditionGivenDocblockType',
                    'DocblockTypeContradiction',
                ],
            ],
            'assignmentInIf' => [
                '<?php
                    function test(int $x = null): int {
                        if (!$x && !($x = rand(0, 10))) {
                            echo "Failed to get non-empty x\n";
                            return -1;
                        }
                        return $x;
                    }',
            ],
            'noRedundantConditionAfterAssignment' => [
                '<?php
                    /** @param int $i */
                    function foo($i): void {
                        if ($i !== null) {
                            $i = (int) $i;

                            if ($i) {}
                        }
                    }',
                'assertions' => [],
                'error_levels' => [
                    'RedundantConditionGivenDocblockType',
                ],
            ],
            'noRedundantConditionAfterDocblockTypeNullCheck' => [
                '<?php
                    class A {
                        /** @var ?int */
                        public $foo;
                    }
                    class B {}

                    /**
                     * @param  A|B $i
                     */
                    function foo($i): void {
                        if (empty($i)) {
                            return;
                        }

                        switch (get_class($i)) {
                            case A::class:
                                if ($i->foo) {}
                                break;

                            default:
                                break;
                        }
                    }',
                'assertions' => [],
                'error_levels' => ['DocblockTypeContradiction'],
            ],
            'noRedundantConditionTypeReplacementWithDocblock' => [
                '<?php
                    class A {}

                    /**
                     * @return A
                     */
                    function getA() {
                        return new A();
                    }

                    $maybe_a = rand(0, 1) ? new A : null;

                    if ($maybe_a === null) {
                        $maybe_a = getA();
                    }

                    if ($maybe_a === null) {}',
                'assertions' => [],
                'error_levels' => [
                    'DocblockTypeContradiction',
                ],
            ],
            'noRedundantConditionAfterPossiblyNullCheck' => [
                '<?php
                    if (rand(0, 1)) {
                        $a = "hello";
                    }

                    if ($a) {}',
                'assertions' => [],
                'error_levels' => ['PossiblyUndefinedGlobalVariable'],
            ],
            'noRedundantConditionAfterFromDocblockRemoval' => [
                '<?php
                    class A {
                        public function foo(): bool {
                            return (bool) rand(0, 1);
                        }
                        public function bar(): bool {
                            return (bool) rand(0, 1);
                        }
                    }

                    /** @return A */
                    function makeA() {
                        return new A;
                    }

                    $a = makeA();

                    if ($a === null) {
                        exit;
                    }

                    if ($a->foo() || $a->bar()) {}',
                'assertions' => [],
                'error_levels' => [
                    'DocblockTypeContradiction',
                ],
            ],
            'noEmptyUndefinedArrayVar' => [
                '<?php
                    if (rand(0,1)) {
                      /** @psalm-suppress UndefinedGlobalVariable */
                      $a = $b[0];
                    } else {
                      $a = null;
                    }
                    if ($a) {}',
                'assertions' => [],
                'error_levels' => ['MixedAssignment', 'MixedArrayAccess'],
            ],
            'noComplaintWithIsNumericThenIsEmpty' => [
                '<?php
                    function takesString(string $s): void {
                      if (!is_numeric($s) || empty($s)) {}
                    }',
            ],
            'noRedundantConditionOnTryCatchVars' => [
                '<?php
                    function trycatch(): void {
                        $value = null;
                        try {
                            if (rand() % 2 > 0) {
                                throw new RuntimeException("Failed");
                            }
                            $value = new stdClass();
                            if (rand() % 2 > 0) {
                                throw new RuntimeException("Failed");
                            }
                        } catch (Exception $e) {
                            if ($value) {
                                var_export($value);
                            }
                        }

                        if ($value) {}
                    }',
            ],
            'noRedundantConditionInFalseCheck' => [
                '<?php
                    $ch = curl_init();
                    if (!$ch) {}',
            ],
            'noRedundantConditionInForCheck' => [
                '<?php
                    class Node
                    {
                        /** @var Node|null */
                        public $next;

                        public function iterate(): void
                        {
                            for ($node = $this; $node !== null; $node = $node->next) {}
                        }
                    }',
            ],
            'noRedundantConditionComparingBool' => [
                '<?php
                    function getBool(): bool {
                      return (bool)rand(0, 1);
                    }

                    function takesBool(bool $b): void {
                      if ($b === getBool()) {}
                    }',
            ],
            'evaluateElseifProperly' => [
                '<?php
                    /** @param string $str */
                    function foo($str): int {
                      if (is_null($str)) {
                        return 1;
                      } else if (strlen($str) < 1) {
                        return 2;
                      }
                      return 2;
                    }',
                'assertions' => [],
                'error_levels' => [
                    'DocblockTypeContradiction',
                    'RedundantConditionGivenDocblockType',
                ],
            ],
            'evaluateArrayCheck' => [
                '<?php
                    function array_check(): void {
                        $data = ["f" => false];
                        while (rand(0, 1) > 0 && !$data["f"]) {
                            $data = ["f" => true];
                        }
                    }',
            ],
            'mixedArrayAssignment' => [
                '<?php
                    /** @param mixed $arr */
                    function foo($arr): void {
                     if ($arr["a"] === false) {
                        $arr["a"] = (bool) rand(0, 1);
                        if ($arr["a"] === false) {}
                      }
                    }',
                'assertions' => [],
                'error_levels' => ['MixedAssignment', 'MixedArrayAccess'],
            ],
            'hardPhpTypeAssertionsOnDocblockType' => [
                '<?php
                    /** @param string|null $bar */
                    function foo($bar): void {
                        if (!is_null($bar) && !is_string($bar)) {
                            throw new \Exception("bad");
                        }

                        if ($bar !== null) {}
                    }',
                'assertions' => [],
                'error_levels' => ['DocblockTypeContradiction'],
            ],
            'isObjectAssertionOnDocblockType' => [
                '<?php
                    class A {}
                    class B {}

                    /** @param A|B $a */
                    function foo($a) : void {
                        if (!is_object($a)) {
                            return;
                        }

                        if ($a instanceof A) {

                        } elseif ($a instanceof B) {

                        } else {
                            throw new \Exception("bad");
                        }
                    }',
                'assertions' => [],
                'error_levels' => ['RedundantConditionGivenDocblockType', 'DocblockTypeContradiction'],
            ],
            'nullToMixedWithNullCheckWithArraykey' => [
                '<?php
                    /** @return array<array-key, mixed> */
                    function getStrings(): array {
                        return ["hello", "world", 50];
                    }

                    $a = getStrings();

                    if (is_string($a[0]) && strlen($a[0]) > 3) {}',
                'assignments' => [],
                'error_levels' => [],
            ],
            'nullToMixedWithNullCheckWithIntKey' => [
                '<?php
                    /** @return array<int, mixed> */
                    function getStrings(): array {
                        return ["hello", "world", 50];
                    }

                    $a = getStrings();

                    if (is_string($a[0]) && strlen($a[0]) > 3) {}',
                'assignments' => [],
                'error_levels' => [],
            ],
            'replaceFalseTypeWithTrueConditionalOnMixedEquality' => [
                '<?php
                    function getData() {
                        return rand(0, 1) ? [1, 2, 3] : false;
                    }

                    $a = false;

                    while ($i = getData()) {
                        if (!$a && $i[0] === 2) {
                            $a = true;
                        }

                        if ($a === false) {}
                    }',
                'assignments' => [],
                'error_levels' => ['MixedAssignment', 'MissingReturnType', 'MixedArrayAccess'],
            ],
            'nullCoalescePossiblyUndefined' => [
                '<?php
                    if (rand(0,1)) {
                        $options = ["option" => true];
                    }

                    $option = $options["option"] ?? false;

                    if ($option) {}',
                'assignments' => [],
                'error_levels' => ['MixedAssignment', 'MixedArrayAccess'],
            ],
            'allowIntValueCheckAfterComparisonDueToOverflow' => [
                '<?php
                    function foo(int $x) : void {
                        $x = $x + 1;

                        if (!is_int($x)) {
                            echo "Is a float.";
                        } else {
                            echo "Is an int.";
                        }
                    }

                    function bar(int $x) : void {
                        $x = $x + 1;

                        if (is_float($x)) {
                            echo "Is a float.";
                        } else {
                            echo "Is an int.";
                        }
                    }',
            ],
            'allowIntValueCheckAfterComparisonDueToOverflowInc' => [
                '<?php
                    function foo(int $x) : void {
                        $x++;

                        if (!is_int($x)) {
                            echo "Is a float.";
                        } else {
                            echo "Is an int.";
                        }
                    }

                    function bar(int $x) : void {
                        $x++;

                        if (is_float($x)) {
                            echo "Is a float.";
                        } else {
                            echo "Is an int.";
                        }
                    }',
            ],
            'allowIntValueCheckAfterComparisonDueToConditionalOverflow' => [
                '<?php
                    function foo(int $x) : void {
                        if (rand(0, 1)) {
                            $x = $x + 1;
                        }

                        if (is_float($x)) {
                            echo "Is a float.";
                        } else {
                            echo "Is an int.";
                        }
                    }',
            ],
            'changeStringValue' => [
                '<?php
                    $concat = "";
                    foreach (["x", "y"] as $v) {
                        if ($concat != "") {
                            $concat .= ", ";
                        }
                        $concat .= "($v)";
                    }',
            ],
            'arrayCanBeEmpty' => [
                '<?php
                    $x = ["key" => "value"];
                    if (rand(0, 1)) {
                        $x = [];
                    }
                    if ($x) {
                        var_export($x);
                    }',
            ],
            'arrayKeyExistsAccess' => [
                '<?php
                    /** @param array<int, string> $arr */
                    function foo(array $arr) : void {
                        if (array_key_exists(1, $arr)) {
                            $a = ($arr[1] === "b") ? true : false;
                        }
                    }',
            ],
            'noRedundantConditionStringNotFalse' => [
                '<?php
                    function foo(string $s) : void {
                        if ($s != false ) {}
                    }',
            ],
            'noRedundantConditionStringNotTrue' => [
                '<?php
                    function foo(string $s) : void {
                        if ($s != true ) {}
                    }',
            ],
            'noRedundantConditionBoolNotFalse' => [
                '<?php
                    function foo(bool $s) : void {
                        if ($s !== false ) {}
                    }',
            ],
            'noRedundantConditionBoolNotTrue' => [
                '<?php
                    function foo(bool $s) : void {
                        if ($s !== true ) {}
                    }',
            ],
            'noRedundantConditionNullableBoolIsFalseOrTrue' => [
                '<?php
                    function foo(?bool $s) : void {
                        if ($s === false ) {} elseif ($s === true) {}
                    }',
            ],
            'noRedundantConditionNullableBoolIsTrueOrFalse' => [
                '<?php
                    function foo(?bool $s) : void {
                        if ($s === true ) {} elseif ($s === false) {}
                    }',
            ],
            'noRedundantConditionAfterCheckingMixedTwice' => [
                '<?php
                    function foo($a) : void {
                        $b = $a ? 1 : 0;
                        $c = $a ? 1 : 0;
                    }',
                [],
                'error_levels' => ['MissingParamType'],
            ],
            'notAlwaysTrueBinaryOp' => [
                '<?php
                    function foo ($a) : void {
                        if (!$a) {}
                        $b = $a && rand(0, 1);
                    }',
                [],
                'error_levels' => ['MissingParamType'],
            ],
            'noRedundantConditionAfterAssertingValue' => [
                '<?php
                    function foo(string $t, bool $b) : void {
                        if (!$b && $t === "a") {
                            return;
                        }

                        if ($t === "c") {
                            if (!$b && bar($t)) {}
                        }
                    }

                    function bar(string $b) : bool {
                        return true;
                    }',
            ],
            'noRedundantConditionBleed' => [
                '<?php
                    $foo = getopt("i");
                    $i = $foo["i"];

                    /** @psalm-suppress TypeDoesNotContainNull */
                    if ($i === null) {
                        exit;
                    }

                    if ($i) {}',
            ],
            'emptyWithoutKnowingArrayType' => [
                '<?php
                    function foo(array $a) : void {
                        if (!empty($a["foo"])) {
                            foreach ($a["foo"] as $key => $_) {
                                if (rand(0, 1)) {
                                    unset($a["foo"][$key]);
                                }
                            }
                            if (empty($a["foo"])) {}
                        }
                    }',
                [],
                ['MixedAssignment', 'MixedArrayAccess', 'MixedArrayOffset'],
            ],
            'emptyKnowingArrayType' => [
                '<?php
                    /**
                     * @param array<string, array<string, int>> $a
                     */
                    function foo(array $a) : void {
                        if (!empty($a["foo"])) {
                            foreach ($a["foo"] as $key => $_) {
                                if (rand(0, 1)) {
                                    unset($a["foo"][$key]);
                                }
                            }
                            if (empty($a["foo"])) {}
                        }
                    }',
            ],
            'suppressRedundantConditionAfterAssertNonEmpty' => [
                '<?php
                    /**
                     * @param array<int> $a
                     */
                    function process(array $a): void {
                        assert(!empty($a));
                        /** @psalm-suppress RedundantConditionGivenDocblockType */
                        assert(is_int($a[0]));
                    }',
            ],
            'allowChecksOnFalsyIf' => [
                '<?php
                    function foo(?string $s) : string {
                        if ($s == null) {
                            if ($s === null) {}

                            return "hello";
                        } else {
                            return $s;
                        }
                    }'
            ],
            'updateArrayAfterUnset' => [
                '<?php
                    /**
                     * @param string[] $arr
                     */
                    function foo(string $s) : void {
                        $dict = ["a" => 1];
                        unset($dict[$s]);
                        if (count($dict)) {}
                    }'
            ],
            'updateArrayAfterUnsetInLoop' => [
                '<?php
                    /**
                     * @param string[] $arr
                     */
                    function foo(array $arr) : void {
                        $dict = ["a" => 1, "b" => 2, "c" => 3];

                        foreach ($arr as $v) {
                            unset($dict[$v]);
                        }

                        if (count($dict)) {}
                    }'
            ],
        ];
    }

    /**
     * @return iterable<string,array{string,error_message:string,2?:string[],3?:bool,4?:string}>
     */
    public function providerInvalidCodeParse()
    {
        return [
            'ifFalse' => [
                '<?php
                    $y = false;
                    if ($y) {}',
                'error_message' => 'TypeDoesNotContainType',
            ],
            'ifNotTrue' => [
                '<?php
                    $y = true;
                    if (!$y) {}',
                'error_message' => 'TypeDoesNotContainType',
            ],
            'ifTrue' => [
                '<?php
                    $y = true;
                    if ($y) {}',
                'error_message' => 'RedundantCondition',
            ],
            'unnecessaryInstanceof' => [
                '<?php
                    class One {
                        public function fooFoo() : void {}
                    }

                    $var = new One();

                    if ($var instanceof One) {
                        $var->fooFoo();
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'failedTypeResolution' => [
                '<?php
                    class A { }

                    /**
                     * @return void
                     */
                    function fooFoo(A $a) {
                        if ($a instanceof A) {
                        }
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'failedTypeResolutionWithDocblock' => [
                '<?php
                    class A { }

                    /**
                     * @param  A $a
                     * @return void
                     */
                    function fooFoo(A $a) {
                        if ($a instanceof A) {
                        }
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'typeResolutionFromDocblockAndInstanceof' => [
                '<?php
                    class A { }

                    /**
                     * @param  A $a
                     * @return void
                     * @psalm-suppress RedundantConditionGivenDocblockType
                     */
                    function fooFoo($a) {
                        if ($a instanceof A) {
                            if ($a instanceof A) {
                            }
                        }
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'typeResolutionRepeatingConditionWithSingleVar' => [
                '<?php
                    $a = rand(0, 10) > 5;
                    if ($a && $a) {}',
                'error_message' => 'RedundantCondition',
            ],
            'typeResolutionRepeatingConditionWithVarInMiddle' => [
                '<?php
                    $a = rand(0, 10) > 5;
                    $b = rand(0, 10) > 5;
                    if ($a && $b && $a) {}',
                'error_message' => 'RedundantCondition',
            ],
            'typeResolutionRepeatingOredConditionWithSingleVar' => [
                '<?php
                    $a = rand(0, 10) > 5;
                    if ($a || $a) {}',
                'error_message' => 'ParadoxicalCondition',
            ],
            'typeResolutionRepeatingOredConditionWithVarInMiddle' => [
                '<?php
                    $a = rand(0, 10) > 5;
                    $b = rand(0, 10) > 5;
                    if ($a || $b || $a) {}',
                'error_message' => 'ParadoxicalCondition',
            ],
            'typeResolutionIsIntAndIsNumeric' => [
                '<?php
                    $c = rand(0, 10) > 5 ? "hello" : 3;
                    if (is_int($c) && is_numeric($c)) {}',
                'error_message' => 'RedundantCondition',
            ],
            'typeResolutionWithInstanceOfAndNotEmpty' => [
                '<?php
                    $x = rand(0, 10) > 5 ? new stdClass : null;
                    if ($x instanceof stdClass && $x) {}',
                'error_message' => 'RedundantCondition',
            ],
            'methodWithMeaninglessCheck' => [
                '<?php
                    class One {
                        /** @return void */
                        public function fooFoo() {}
                    }

                    class B {
                        /** @return void */
                        public function barBar(One $one) {
                            if (!$one) {
                                // do nothing
                            }

                            $one->fooFoo();
                        }
                    }',
                'error_message' => 'TypeDoesNotContainType',
            ],
            'twoVarLogicNotNestedWithElseifNegatedInIf' => [
                '<?php
                    function foo(?string $a, ?string $b): ?string {
                        if ($a) {
                            $a = null;
                        } elseif ($b) {
                            // do nothing here
                        } else {
                            return "bad";
                        }

                        if (!$a) return $b;
                        return $a;
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'refineTypeInMethodCall' => [
                '<?php
                    class A {}

                    /** @return ?A */
                    function getA() {
                      return rand(0, 1) ? new A : null;
                    }

                    function takesA(A $a): void {}

                    $a = getA();
                    if ($a instanceof A) {}
                    /** @psalm-suppress PossiblyNullArgument */
                    takesA($a);
                    if ($a instanceof A) {}',
                'error_message' => 'RedundantCondition - src' . DIRECTORY_SEPARATOR . 'somefile.php:15',
            ],
            'replaceFalseType' => [
                '<?php
                    function foo(bool $b) : void {
                      if (!$b) {
                        $b = true;
                      }

                      if ($b) {}
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'replaceTrueType' => [
                '<?php
                    function foo(bool $b) : void {
                      if ($b) {
                        $b = false;
                      }

                      if ($b) {}
                    }',
                'error_message' => 'TypeDoesNotContainType - src' . DIRECTORY_SEPARATOR . 'somefile.php:7',
            ],
            'disallowFloatCheckAfterSettingToVar' => [
                '<?php
                    function foo(int $x) : void {
                        if (rand(0, 1)) {
                            $x = 125;
                        }

                        if (is_float($x)) {
                            echo "Is a float.";
                        } else {
                            echo "Is an int.";
                        }
                    }',
                'error_message' => 'TypeDoesNotContainType - src' . DIRECTORY_SEPARATOR . 'somefile.php:7',
            ],
            'disallowTwoIntValueChecksDueToConditionalOverflow' => [
                '<?php
                    function foo(int $x) : void {
                        $x = $x + 1;

                        if (is_int($x)) {
                        } elseif (is_int($x)) {}
                    }',
                'error_message' => 'TypeDoesNotContainType - src' . DIRECTORY_SEPARATOR . 'somefile.php:6',
            ],
            'redundantEmptyArray' => [
                '<?php
                    $x = ["key" => "value"];
                    if ($x) {
                        var_export($x);
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'redundantConditionStringNotFalse' => [
                '<?php
                    function foo(string $s) : void {
                        if ($s !== false ) {}
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'redundantConditionStringNotTrue' => [
                '<?php
                    function foo(string $s) : void {
                        if ($s !== true ) {}
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'redundantConditionAfterRemovingFalse' => [
                '<?php
                    $s = rand(0, 1) ? rand(0, 5) : false;

                    if ($s !== false) {
                        if (is_int($s)) {}
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'redundantConditionAfterRemovingTrue' => [
                '<?php
                    $s = rand(0, 1) ? rand(0, 5) : true;

                    if ($s !== true) {
                        if (is_int($s)) {}
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'impossibleNullEquality' => [
                '<?php
                    $i = 5;
                    echo $i !== null;',
                'error_message' => 'RedundantCondition',
            ],
            'impossibleTrueEquality' => [
                '<?php
                    $i = 5;
                    echo $i !== true;',
                'error_message' => 'RedundantCondition',
            ],
            'impossibleFalseEquality' => [
                '<?php
                    $i = 5;
                    echo $i !== false;',
                'error_message' => 'RedundantCondition',
            ],
            'impossibleNumberEquality' => [
                '<?php
                    $i = 5;
                    echo $i !== 3;',
                'error_message' => 'RedundantCondition',
            ],
            'alwaysTrueBinaryOp' => [
                '<?php
                    function foo ($a) : void {
                        if (!$a) return;
                        $b = $a && rand(0, 1);
                    }',
                'error_message' => 'RedundantCondition',
                'error_levels' => ['MissingParamType'],
            ],
            'negatedInstanceof' => [
                '<?php
                    class A {}
                    class B {}

                    function foo(A $a) : void {
                        if (!$a instanceof B) {}
                    }',
                'error_message' => 'RedundantCondition',
            ],
            'redundantInstanceof' => [
                '<?php
                    /** @param Exception $a */
                    function foo($a) : void {
                        if ($a instanceof \Exception) {}
                    }',
                'error_message' => 'RedundantConditionGivenDocblockType',
            ],
            'preventDocblockTypesBeingIdenticalToTrue' => [
                '<?php
                    class A {}

                    /**
                     * @param  A $a
                     */
                    function foo($a, $b) : void {
                        if ($a === true) {}
                    }',
                'error_message' => 'DocblockTypeContradiction',
            ],
            'preventDocblockTypesBeingIdenticalToTrueReversed' => [
                '<?php
                    class A {}

                    /**
                     * @param  A $a
                     */
                    function foo($a, $b) : void {
                        if (true === $a) {}
                    }',
                'error_message' => 'DocblockTypeContradiction',
            ],
            'preventDocblockTypesBeingIdenticalToFalse' => [
                '<?php
                    class A {}

                    /**
                     * @param  A $a
                     */
                    function foo($a, $b) : void {
                        if ($a === false) {}
                    }',
                'error_message' => 'DocblockTypeContradiction',
            ],
            'preventDocblockTypesBeingIdenticalToFalseReversed' => [
                '<?php
                    class A {}

                    /**
                     * @param  A $a
                     */
                    function foo($a, $b) : void {
                        if (false === $a) {}
                    }',
                'error_message' => 'DocblockTypeContradiction',
            ],
            'preventDocblockTypesBeingSameAsEmptyArrayReversed' => [
                '<?php
                    class A {}

                    /**
                     * @param  A $a
                     */
                    function foo($a, $b) : void {
                        if ([] == $a) {}
                    }',
                'error_message' => 'DocblockTypeContradiction',
            ],
            'preventDocblockTypesBeingIdenticalToEmptyArrayReversed' => [
                '<?php
                    class A {}

                    /**
                     * @param  A $a
                     */
                    function foo($a, $b) : void {
                        if ([] === $a) {}
                    }',
                'error_message' => 'DocblockTypeContradiction',
            ],
            'preventTypesBeingIdenticalToEmptyArrayReversed' => [
                '<?php
                    class A {}

                    function foo(A $a, $b) : void {
                        if ([] === $a) {}
                    }',
                'error_message' => 'TypeDoesNotContainType',
            ],
        ];
    }
}