fc29d26879
* Added test to enforce that all supported annotations are documented Well, at least mentioned. Refs vimeo/psalm#3816 * Type things * Make things pretty * Only check @psalm- annotations, group * Add documentation for `@psalm-require-extends` and `@psalm-require-implements` * Dropped logicalOr that has become redundant * Add explicit tag * Document @psalm-template * Add @psalm-template-covariant * Document `@psalm-method` * Add list of undocumented docblock annotations Co-authored-by: Matthew Brown <github@muglug.com> |
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annotating_code | ||
manipulating_code | ||
running_psalm | ||
security_analysis | ||
how_psalm_works.md | ||
README.md | ||
what_makes_psalm_complicated.md |
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 amixed
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, soif ($a && $a) {}
andif ($a && !$a) {}
are both treated as issues. Psalm also keeps track of logical assertions made in prior code paths, preventing issues likeif ($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
Wherever possible Psalm will run its analysis in parallel to save time. Useful for large codebases, it has a massive impact on performance. -
Incremental checks
By default Psalm only analyses files that have changed and files that reference those changed files.
Example output
Given a file implode_strings.php
:
<?php
$a = ['foo', 'bar'];
echo implode($a, ' ');
> ./vendor/bin/psalm implode_strings.php
ERROR: InvalidArgument - somefile.php:3:14 - Argument 1 of implode expects `string`, `array` provided (see https://psalm.dev/004)
Inspirations
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.
Index
- Running Psalm:
- Annotating code:
- Manipulating code: