1
0
mirror of https://github.com/danog/psalm.git synced 2024-11-30 04:39:00 +01:00
psalm/docs/README.md
2020-12-19 18:09:05 +00:00

73 lines
3.2 KiB
Markdown
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# 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**<br />
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**<br />
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**<br />
Psalm checks that all properties of a given object have values after the constructor is called.
- **Taint analysis**<br />
Psalm can [detect security vulnerabilities](https://psalm.dev/articles/detect-security-vulnerabilities-with-psalm) in your code.
- **Language Server**<br />
Psalm has a Language Server thats [compatible with a range of different IDEs](https://psalm.dev/docs/running_psalm/language_server/).
- **Automatic fixes**<br />
Psalm can [fix many of the issues it finds automatically](https://psalm.dev/docs/manipulating_code/fixing/).
- **Automatic refactoring**<br />
Psalm can also [perform simple refactors](https://psalm.dev/docs/manipulating_code/refactoring/) from the command line.
## Example output
Given a file `implode_strings.php`:
```php
<?php
$a = ['foo', 'bar'];
echo implode($a, ' ');
```
```bash
> ./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](https://github.com/etsy/phan), which uses nikic's [php-ast](https://github.com/nikic/php-ast) extension to create an abstract syntax tree
- Facebook's [Hack](http://hacklang.org/), a PHP-like language that supports many advanced typing features natively, so docblocks aren't necessary.
## Index
- Running Psalm:
- [Installation](running_psalm/installation.md)
- [Configuration](running_psalm/configuration.md)
- Plugins
- [Using plugins](running_psalm/plugins/using_plugins.md)
- [Authoring plugins](running_psalm/plugins/authoring_plugins.md)
- [How Psalm represents types](running_psalm/plugins/plugins_type_system.md)
- [Command line usage](running_psalm/command_line_usage.md)
- [IDE support](running_psalm/language_server.md)
- Handling errors:
- [Dealing with code issues](running_psalm/dealing_with_code_issues.md)
- [Issue Types](running_psalm/issues.md)
- [Checking non-PHP files](running_psalm/checking_non_php_files.md)
- Annotating code:
- [Typing in Psalm](annotating_code/typing_in_psalm.md)
- [Supported Annotations](annotating_code/supported_annotations.md)
- [Template Annotations](annotating_code/templated_annotations.md)
- Manipulating code:
- [Fixing code](manipulating_code/fixing.md)
- [Refactoring code](manipulating_code/refactoring.md)