@psalm-assert-if-true =Type= changes two things versus a plain
type assertion:
1. The true branch still narrows (here $value becomes int).
2. The false branch does *not* get the negation — $value may still be
an int. A plain int assertion would make the false branch !int.
The true-branch probe below checks that the = form is recognised and
still narrows. The false branch is left unprobed as a required diagnostic
because tools that ignore the tag and tools that honour equality look the
same there (no "always false" noise either way).
References:
- Psalm assertion_syntax.md: Equality assertions (=int)
- PHPStan narrowing-types.md: The = operator| Analyzer | Version | Result | Diagnostics |
|---|---|---|---|
| phan | 6.0.7Phan 6.0.7 php-ast version 1.1.3 PHP version used to run Phan: 8.5.9 | Not enforced | No diagnostics reported.
|
| phpstan | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Not enforced reported Lv.4+ | phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Call to function is_string() with int will always evaluate to false. [identifier=function.impossibleType] [reported-from-level=4] With strict-rulesphpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Call to function is_string() with int will always evaluate to false. [identifier=function.impossibleType]
Expectation diffLine 39: Unexpected errors ["Call to function is_string() with int will always evaluate to false. [identifier=function.impossibleType] [reported-from-level=4]"] |
| psalm | 6.16.1Psalm 6.16.1@f1f5de594dc76faf8784e02d3dc4716c91c6f6ac next: 7.0.0-beta19 |
Not enforced (pzoom≠) | phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Type int for $value is never string [TypeDoesNotContainType] phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Type int for $value is never string [RedundantCondition] pzoom (Psalm port)No diagnostics from pzoom.
Expectation diffLine 39: Unexpected errors ["Type int for $value is never string [TypeDoesNotContainType]","Type int for $value is never string [RedundantCondition]"] |
| mago | 1.46.0mago 1.46.0 | Not enforced ⚠ 1 false positive | phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Impossible type assertion: `$value` of type `int` can never be `string`. [impossible-type-comparison] phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Redundant ternary operator: condition is always falsy. [impossible-condition]
Expectation diffLine 39: Unexpected errors ["Impossible type assertion: `$value` of type `int` can never be `string`. [impossible-type-comparison]","Redundant ternary operator: condition is always falsy. [impossible-condition]"] |
| mir | 0.70.1mir 0.70.1 | Not enforced | No diagnostics reported.
|
| phpantom | 0.9.0phpantom_lsp 0.9.0 | Not enforced | No diagnostics reported.
|
| intelephense | 1.18.5intelephense 1.18.5 | Not enforced | No diagnostics reported.
|
| phpy | 0.2.0phpy 0.2.0 | Not enforced | No diagnostics reported.
|
| qodana | 262.8665.325Qodana 262.8665.325 | Not enforced | No diagnostics reported.
|
| noverify | 0.5.5NoVerify, version 0.5.5: built on: 2025.04.22 14:36:46 OS: r-kuchinskas arm64 Commit: 4774b82f8adc53fbef38f95e97af4b953b4d1529 | Not enforced | No diagnostics reported.
|
| steins | 0.1.5steins 0.1.5 (2026-08-12 revision 39b4cc1) | Not enforced | No diagnostics reported.
|
| phpstan-strict | 2.2.8PHPStan - PHP Static Analysis Tool 2.2.8 | Not enforced ⚠ 1 false positive | phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Call to function is_string() with int will always evaluate to false. [identifier=function.impossibleType]
Expectation diffLine 39: Unexpected errors ["Call to function is_string() with int will always evaluate to false. [identifier=function.impossibleType]"] |
| psalm-next | 7.0.0-beta19Psalm 7.0.0-beta19@7e751c06a756fa64dc4c759c09fe4a173afcb433 | Not enforced ⚠ 1 false positive | phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Type int for $value is never string [TypeDoesNotContainType] phpdoc_advanced_vendor_prefixed_assert_equality_psalm.php:39: Type int for $value is never string [RedundantCondition]
Expectation diffLine 39: Unexpected errors ["Type int for $value is never string [TypeDoesNotContainType]","Type int for $value is never string [RedundantCondition]"] |
<?php
declare(strict_types=1);
namespace Conformance\Tests\PhpdocAdvancedVendorPrefixedAssertEqualityPsalm;
/**
* Equality assertion form `@psalm-assert-if-true =Type`.
*
* Prefixing the asserted type with `=` changes two things versus a plain
* type assertion:
*
* 1. The true branch still narrows (here `$value` becomes `int`).
* 2. The false branch does *not* get the negation — `$value` may still be
* an int. A plain `int` assertion would make the false branch `!int`.
*
* The true-branch probe below checks that the `=` form is recognised and
* still narrows. The false branch is left unprobed as a required diagnostic
* because tools that ignore the tag and tools that honour equality look the
* same there (no "always false" noise either way).
*
* References:
* - Psalm assertion_syntax.md: Equality assertions (`=int`)
* - PHPStan narrowing-types.md: The `=` operator
*/
/**
* @psalm-assert-if-true =int $value
*/
function equalsFive(mixed $value): bool // T: @psalm-assert-if-true =int
{
return \is_int($value) && $value === 5;
}
function takesInt(int $value): void
{
}
function example(mixed $value): void
{
if (equalsFive($value)) {
takesInt($value); // V
// True branch: equality still asserts int, so is_string is impossible.
echo \is_string($value) ? 'string' : 'int'; // E?: in the true branch of =int, is_string() is always false
} else {
// False branch of =int must NOT force !int: `$value` may still be int.
// A tool that treats `=int` as plain `int` would flag is_int as always
// false here; tools that honour equality (or ignore the tag) stay quiet.
echo \is_int($value) ? 'maybe-int' : 'other';
}
}