Features

Conditional Return Types

Psalm now supports conditional return types.

Improved --diff mode

Psalm's --diff mode should now produce all the same issues that running without --diff does (#3024, #3032)

Additionally, it should now run much faster for small changesets.

With this change, --diff-methods is now implied when running --diff.

Improve detection of problematic array types

Previously when dealing with arrays the mixed type subsumed everything in its path. Since Psalm converts any bare PHP array types to array<array-key, mixed>, that mixed type can hide real bugs, such as in the following code: https://psalm.dev/r/a97351e870 (this corresponds to code that caused an outage on vimeo.com).

This version of Psalm introduces slightly more careful array handling, and allows unions on mixed inside arrays in certain circumstances to allow you to catch more of these sorts of errors.

Other features

• @psalm-property-read and @psalm-property-write are now supported as prefixed versions of @property-read and @property-write - thanks @iggyvolz (#3013)
• Psalter can now be run without using cache (via --no-cache) - thanks @orklah!
• You can now use a @psalm-trace annotation to figure out what type Psalm infers for a given variable – thanks @m0003r (#3080, #3106)
• Docblock inheritance for function params is now just position-dependent, not name dependent as previously (#2722)

Bugfixes

• improve handling of templated assertions when calling array_filter (#3008)
• fix templating of properties (#3027, #3035)
• @return static is now enforced in places it should have been, but was not
• variables set in conditional branches of while expressions are now more completely understood (#3034)
• Psalter don’t suggest hard return types for functions that don’t always return (#3030)
• Allow __invoke to be called on unions with non-objects (#3033)
• Allow inheritance from classes that only exist in stubs (#2191)
• Fix class constant access rules for constant defined in subclass (#3014)
• Use a better method for determining switch case complexity, preventing crashes (#2728)
• @LeSuisse updated the return value of zip_open
• Improve handling of generators (#3058, #3057)
• Prevent array_key_exists calls from changing the array type (#3061)
• Allow comparing self-returning trait methods in 7.4 without a MethodSignatureMismatch (#3042)
• Perform more intelligent templating for callable arrays passed to array_map (#3039)
• Improve handling of intersection types when merging templated types (#3082)
• Psalm now infers template upper and lower bounds correctly, and will present more useful error messages when they don’t match (#3084)
• Improve handling of elseif clauses (#3091)
• Forget what's been asserted in methods when checking constructor initialisation (#3096)
• @Ocramius improved the return type for ReflectionProperty::getType() (#3093)
• @lhchavez added the ability to annotate intersections of arrays in docblocks (#3064)
• @mpesari updated property types for mysqli objects (#3114)
• Prevent a crash when encountering a @method annotation with a dash in the method name (#3107)
• Perform intersections on arrays after assertions on their key types (#3095)
• round always returns a float (#3092)
• Allow instanceof checks with templated class-strings (#3116)
• All caches are now invalidated when the composer lockfile changes (#3117)
• Some method getters are now automatically memoised - thanks @m0003r (#3122)