mirror of https://github.com/danog/psalm.git synced 2024-11-27 04:45:20 +01:00

History

Maks Rafalko b6873b0e72 `ignoreInternalFunctionFalseReturn` default to false in XSD, but documentations says `true` See `27598f508e/config.xsd (L46)`		2020-03-12 09:12:23 -04:00
..
annotating_code	Add line break	2020-02-23 00:41:19 -05:00
manipulating_code	Fix #2173 - remove @var annotations automatically	2019-09-26 15:08:05 -04:00
running_psalm	`ignoreInternalFunctionFalseReturn` default to false in XSD, but documentations says `true`	2020-03-12 09:12:23 -04:00
how_psalm_works.md	Change DependencyFinderVisitor name to ReflectorVisitor and update docs	2018-11-13 14:09:43 -05:00
README.md	Update readme	2020-02-18 23:50:53 -05:00
what_makes_psalm_complicated.md	stripping trailing whitespace	2019-02-11 18:39:19 -05:00

About Psalm

Psalm is a static analysis tool that attempts to dig into your program and find as many type-related bugs as possible.

It has a few features that go further than other similar tools:

Mixed type warnings
If Psalm cannot infer a type for an expression then it uses a mixed placeholder type. mixed types can sometimes mask bugs, so keeping track of them helps you avoid a number of common pitfalls.
Intelligent logic checks
Psalm keeps track of logical assertions made about your code, so if ($a && $a) {} and if ($a && !$a) {} are both treated as issues. Psalm also keeps track of logical assertions made in prior code paths, preventing issues like if ($a) {} elseif ($a) {}.
Property initialisation checks
Psalm checks that all properties of a given object have values after the constructor is called.

Psalm also has a few features to make it perform as well as possible on large codebases:

Multi-threaded mode
Whereever possible Psalm will run its analysis in parallel to save time. Useful for large codebases, it has a massive impact on performance.
Incremental checks
When using the --diff command line option, Psalm will only analyse files that have changed and files that reference them.

Example output

// somefile.php
<?php
$a = ['foo', 'bar'];
echo implode($a, ' ');

> ./vendor/bin/psalm somefile.php
ERROR: InvalidArgument - somefile.php:3:14 - Argument 1 of implode expects `string`, `array` provided

There are two main inspirations for Psalm:

Etsy's Phan, which uses nikic's php-ast extension to create an abstract syntax tree
Facebook's Hack, a PHP-like language that supports many advanced typing features natively, so docblocks aren't necessary.