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

History

Philip Hofstetter 395cf587d3 add plugin hook to be called after every function call compared to AfterFunctionCallAnalysisInterface which gets only called after a call to a function declared within the project, a plugin implementing AfterEveryFunctionCallAnalysisInterface will get called for every function call, including calls of PHP builtins. On the other hand, this interface doesn't allow modification of the code nor tweaking the return type, but it's still useful for accounting purposes and for depreacting calls to PHP builtins this fixes #2804		2020-02-13 09:10:24 -05:00
..
annotating_code	Update typing_in_psalm.md	2020-02-07 10:55:44 -05:00
manipulating_code	Fix #2173 - remove @var annotations automatically	2019-09-26 15:08:05 -04:00
running_psalm	add plugin hook to be called after every function call	2020-02-13 09:10:24 -05:00
how_psalm_works.md	Change DependencyFinderVisitor name to ReflectorVisitor and update docs	2018-11-13 14:09:43 -05:00
README.md	Remove thing that needn't be code	2019-08-16 22:21:17 -04:00
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. Any mixed type is a sign of an insufficiently-documented codebase. You can configure Psalm warn when encountering mixed types by adding totallyTyped="true" attribute to your XML config file.
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.
Support for complicated array shapes
Psalm has support for object-like arrays, allowing you to specify types for all keys of an array if you so wish.

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

Multi-threaded mode
Using the --threads=[X] command line option will run Psalm's analysis stage on [X] threads. 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.