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## Prerequisites
PHPStan requires PHP >= 7.1. You have to run it in environment with PHP 7.x but the actual code does not have to use
PHP 7.x features. (Code written for PHP 5.6 and earlier can run on 7.x mostly unmodified.)
PHPStan works best with modern object-oriented code. The more strongly-typed your code is, the more information
you give PHPStan to work with.
Properly annotated and typehinted code (class properties, function and method arguments, return types) helps
not only static analysis tools but also other people that work with the code to understand it.
## Installation
To start performing analysis on your code, require PHPStan in [Composer](https://getcomposer.org/):
```
composer require --dev phpstan/phpstan
```
Composer will install PHPStan's executable in its `bin-dir` which defaults to `vendor/bin`.
If you have conflicting dependencies or you want to install PHPStan globally, the best way is via a PHAR archive. You will always find the latest stable PHAR archive below the [release notes](https://github.com/phpstan/phpstan/releases). You can also use the [phpstan/phpstan-shim](https://packagist.org/packages/phpstan/phpstan-shim) package to install PHPStan via Composer without the risk of conflicting dependencies.
You can also use [PHPStan via Docker](https://github.com/phpstan/docker-image).
## First run
To let PHPStan analyse your codebase, you have to use the `analyse` command and point it to the right directories.
So, for example if you have your classes in directories `src` and `tests`, you can run PHPStan like this:
```bash
vendor/bin/phpstan analyse src tests
```
PHPStan will probably find some errors, but don't worry, your code might be just fine. Errors found
on the first run tend to be:
* Extra arguments passed to functions (e. g. function requires two arguments, the code passes three)
* Extra arguments passed to print/sprintf functions (e. g. format string contains one placeholder, the code passes two values to replace)
* Obvious errors in dead code
* Magic behaviour that needs to be defined. See [Extensibility](#extensibility).
After fixing the obvious mistakes in the code, look to the following section
for all the configuration options that will bring the number of reported errors to zero
making PHPStan suitable to run as part of your continuous integration script.
## Rule levels
If you want to use PHPStan but your codebase isn't up to speed with strong typing
and PHPStan's strict checks, you can choose from currently 8 levels
(0 is the loosest and 7 is the strictest) by passing `--level` to `analyse` command. Default level is `0`.
This feature enables incremental adoption of PHPStan checks. You can start using PHPStan
with a lower rule level and increase it when you feel like it.
You can also use `--level max` as an alias for the highest level. This will ensure that you will always use the highest level when upgrading to new versions of PHPStan. Please note that this can create a significant obstacle when upgrading to a newer version because you might have to fix a lot of code to bring the number of errors down to zero.
## Extensibility
Unique feature of PHPStan is the ability to define and statically check "magic" behaviour of classes -
accessing properties that are not defined in the class but are created in `__get` and `__set`
and invoking methods using `__call`.
See [Class reflection extensions](#class-reflection-extensions), [Dynamic return type extensions](#dynamic-return-type-extensions) and [Type-specifying extensions](#type-specifying-extensions).
You can also install official framework-specific extensions:
* [Doctrine](https://github.com/phpstan/phpstan-doctrine)
* [PHPUnit](https://github.com/phpstan/phpstan-phpunit)
* [Nette Framework](https://github.com/phpstan/phpstan-nette)
* [Dibi - Database Abstraction Library](https://github.com/phpstan/phpstan-dibi)
* [PHP-Parser](https://github.com/phpstan/phpstan-php-parser)
* [beberlei/assert](https://github.com/phpstan/phpstan-beberlei-assert)
* [webmozart/assert](https://github.com/phpstan/phpstan-webmozart-assert)
* [Symfony Framework](https://github.com/phpstan/phpstan-symfony)
* [Mockery](https://github.com/phpstan/phpstan-mockery)
Unofficial extensions for other frameworks and libraries are also available:
* [Phony](https://github.com/eloquent/phpstan-phony)
* [Prophecy](https://github.com/Jan0707/phpstan-prophecy)
* [Laravel](https://github.com/nunomaduro/larastan)
* [myclabs/php-enum](https://github.com/timeweb/phpstan-enum)
* [Yii2](https://github.com/proget-hq/phpstan-yii2)
* [PhpSpec](https://github.com/proget-hq/phpstan-phpspec)
* [TYPO3](https://github.com/sascha-egerer/phpstan-typo3)
New extensions are becoming available on a regular basis!
## Configuration
Config file is passed to the `phpstan` executable with `-c` option:
```bash
vendor/bin/phpstan analyse -l 4 -c phpstan.neon src tests
```
When using a custom project config file, you have to pass the `--level` (`-l`)
option to `analyse` command (default value does not apply here).
If you do not provide config file explicitly, PHPStan will look for
files named `phpstan.neon` or `phpstan.neon.dist` in current directory.
The resolution priority is as such:
1. If config file is provided on command line, it is used.
2. If config file `phpstan.neon` exists in current directory, it will be used.
3. If config file `phpstan.neon.dist` exists in current directory, it will be used.
4. If none of the above is true, no config will be used.
[NEON file format](https://ne-on.org/) is very similar to YAML.
All the following options are part of the `parameters` section.
#### Configuration variables
- `%rootDir%` - root directory where PHPStan resides (i.e. `vendor/phpstan/phpstan` in Composer installation)
- `%currentWorkingDirectory%` - current working directory where PHPStan was executed
#### Configuration options
- `tmpDir` - specifies the temporary directory used by PHPStan cache (defaults to `sys_get_temp_dir() . '/phpstan'`)
- `level` - specifies analysis level - if specified, `-l` option is not required
- `paths` - specifies analysed paths - if specified, paths are not required to be passed as arguments
### Autoloading
PHPStan uses Composer autoloader so the easiest way how to autoload classes
is through the `autoload`/`autoload-dev` sections in composer.json.
#### Specify paths to scan
If PHPStan complains about some non-existent classes and you're sure the classes
exist in the codebase AND you don't want to use Composer autoloader for some reason,
you can specify directories to scan and concrete files to include using
`autoload_directories` and `autoload_files` array parameters:
```
parameters:
autoload_directories:
- %rootDir%/../../../build
autoload_files:
- %rootDir%/../../../generated/routes/GeneratedRouteList.php
```
`%rootDir%` is expanded to the root directory where PHPStan resides.
#### Autoloading for global installation
PHPStan supports global installation using [`composer global`](https://getcomposer.org/doc/03-cli.md#global) or via a [PHAR archive](#installation).
In this case, it's not part of the project autoloader, but it supports autodiscovery of the Composer autoloader
from current working directory residing in `vendor/`:
```bash
cd /path/to/project
phpstan analyse src tests # looks for autoloader at /path/to/project/vendor/autoload.php
```
If you have your dependencies installed at a different path
or you're running PHPStan from a different directory,
you can specify the path to the autoloader with the `--autoload-file|-a` option:
```bash
phpstan analyse --autoload-file=/path/to/autoload.php src tests
```
### Exclude files from analysis
If your codebase contains some files that are broken on purpose
(e. g. to test behaviour of your application on files with invalid PHP code),
you can exclude them using the `excludes_analyse` array parameter. String at each line
is used as a pattern for the [`fnmatch`](https://secure.php.net/manual/en/function.fnmatch.php) function.
```
parameters:
excludes_analyse:
- %rootDir%/../../../tests/*/data/*
```
### Include custom extensions
If your codebase contains php files with extensions other than the standard .php extension then you can add them
to the `fileExtensions` array parameter:
```
parameters:
fileExtensions:
- php
- module
- inc
```
### Universal object crates
Classes without predefined structure are common in PHP applications.
They are used as universal holders of data - any property can be set and read on them. Notable examples
include `stdClass`, `SimpleXMLElement` (these are enabled by default), objects with results of database queries etc.
Use `universalObjectCratesClasses` array parameter to let PHPStan know which classes
with these characteristics are used in your codebase:
```
parameters:
universalObjectCratesClasses:
- Dibi\Row
- Ratchet\ConnectionInterface
```
### Add non-obviously assigned variables to scope
If you use some variables from a try block in your catch blocks, set `polluteCatchScopeWithTryAssignments` boolean parameter to `true`.
```php
try {
$author = $this->getLoggedInUser();
$post = $this->postRepository->getById($id);
} catch (PostNotFoundException $e) {
// $author is probably defined here
throw new ArticleByAuthorCannotBePublished($author);
}
```
If you are enumerating over all possible situations in if-elseif branches
and PHPStan complains about undefined variables after the conditions, you can write
an else branch with throwing an exception:
```php
if (somethingIsTrue()) {
$foo = true;
} elseif (orSomethingElseIsTrue()) {
$foo = false;
} else {
throw new ShouldNotHappenException();
}
doFoo($foo);
```
I recommend leaving `polluteCatchScopeWithTryAssignments` set to `false` because it leads to a clearer and more maintainable code.
### Custom early terminating method calls
Previous example showed that if a condition branches end with throwing an exception, that branch does not have
to define a variable used after the condition branches end.
But exceptions are not the only way how to terminate execution of a method early. Some specific method calls
can be perceived by project developers also as early terminating - like a `redirect()` that stops execution
by throwing an internal exception.
```php
if (somethingIsTrue()) {
$foo = true;
} elseif (orSomethingElseIsTrue()) {
$foo = false;
} else {
$this->redirect('homepage');
}
doFoo($foo);
```
These methods can be configured by specifying a class on whose instance they are called like this:
```
parameters:
earlyTerminatingMethodCalls:
Nette\Application\UI\Presenter:
- redirect
- redirectUrl
- sendJson
- sendResponse
```
### Ignore error messages with regular expressions
If some issue in your code base is not easy to fix or just simply want to deal with it later,
you can exclude error messages from the analysis result with regular expressions:
```
parameters:
ignoreErrors:
- '#Call to an undefined method [a-zA-Z0-9\\_]+::method\(\)#'
- '#Call to an undefined method [a-zA-Z0-9\\_]+::expects\(\)#'
- '#Access to an undefined property PHPUnit_Framework_MockObject_MockObject::\$[a-zA-Z0-9_]+#'
- '#Call to an undefined method PHPUnit_Framework_MockObject_MockObject::[a-zA-Z0-9_]+\(\)#'
```
To exclude an error in a specific directory or file, specify a `path` along with the `message`:
```
parameters:
ignoreErrors:
-
message: '#Call to an undefined method [a-zA-Z0-9\\_]+::method\(\)#'
path: %currentWorkingDirectory%/some/dir/SomeFile.php
-
message: '#Call to an undefined method [a-zA-Z0-9\\_]+::method\(\)#'
path: %currentWorkingDirectory%/other/dir/*
- '#Other error to catch anywhere#'
```
If some of the patterns do not occur in the result anymore, PHPStan will let you know
and you will have to remove the pattern from the configuration. You can turn off
this behaviour by setting `reportUnmatchedIgnoredErrors` to `false` in PHPStan configuration.
### Bootstrap file
If you need to initialize something in PHP runtime before PHPStan runs (like your own autoloader),
you can provide your own bootstrap file:
```
parameters:
bootstrap: %rootDir%/../../../phpstan-bootstrap.php
```
### Custom rules
PHPStan allows writing custom rules to check for specific situations in your own codebase. Your rule class
needs to implement the `PHPStan\Rules\Rule` interface and registered as a service in the configuration file:
```
services:
-
class: MyApp\PHPStan\Rules\DefaultValueTypesAssignedToPropertiesRule
tags:
- phpstan.rules.rule
```
For inspiration on how to implement a rule turn to [src/Rules](https://github.com/phpstan/phpstan/tree/master/src/Rules)
to see a lot of built-in rules.
Check out also [phpstan-strict-rules](https://github.com/phpstan/phpstan-strict-rules) repository for extra strict and opinionated rules for PHPStan!
### Custom error formatters
PHPStan outputs errors via formatters. You can customize the output by implementing the `ErrorFormatter` interface in a new class and add it to the configuration. For existing formatters, see next chapter.
```php
interface ErrorFormatter
{
/**
* Formats the errors and outputs them to the console.
*
* @param \PHPStan\Command\AnalysisResult $analysisResult
* @param \Symfony\Component\Console\Style\OutputStyle $style
* @return int Error code.
*/
public function formatErrors(
AnalysisResult $analysisResult,
\Symfony\Component\Console\Style\OutputStyle $style
): int;
}
```
Register the formatter in your `phpstan.neon`:
```
services:
errorFormatter.awesome:
class: App\PHPStan\AwesomeErrorFormatter
```
Use the name part after `errorFormatter.` as the CLI option value:
```bash
vendor/bin/phpstan analyse -c phpstan.neon -l 4 --error-format awesome src tests
```
### Existing error formatters to be used
You can pass the following keywords to the `--error-format=X` parameter in order to affect the output:
- `table`: Default. Grouped errors by file, colorized. For human consumption.
- `raw`: Contains one error per line, with path to file, line number, and error description
- `checkstyle`: Creates a checkstyle.xml compatible output. Note that you'd have to redirect output into a file in order to capture the results for later processing.
## Class reflection extensions
Classes in PHP can expose "magical" properties and methods decided in run-time using
class methods like `__get`, `__set` and `__call`. Because PHPStan is all about static analysis
(testing code for errors without running it), it has to know about those properties and methods beforehand.
When PHPStan stumbles upon a property or a method that is unknown to built-in class reflection, it iterates
over all registered class reflection extensions until it finds one that defines the property or method.
Class reflection extension cannot have `PHPStan\Broker\Broker` (service for obtaining class reflections) injected in the constructor due to circular reference issue, but the extensions can implement `PHPStan\Reflection\BrokerAwareExtension` interface to obtain Broker via a setter.
### Properties class reflection extensions
This extension type must implement the following interface:
```php
namespace PHPStan\Reflection;
interface PropertiesClassReflectionExtension
{
public function hasProperty(ClassReflection $classReflection, string $propertyName): bool;
public function getProperty(ClassReflection $classReflection, string $propertyName): PropertyReflection;
}
```
Most likely you will also have to implement a new `PropertyReflection` class:
```php
namespace PHPStan\Reflection;
interface PropertyReflection
{
public function getType(): Type;
public function getDeclaringClass(): ClassReflection;
public function isStatic(): bool;
public function isPrivate(): bool;
public function isPublic(): bool;
}
```
This is how you register the extension in project's PHPStan config file:
```
services:
-
class: App\PHPStan\PropertiesFromAnnotationsClassReflectionExtension
tags:
- phpstan.broker.propertiesClassReflectionExtension
```
### Methods class reflection extensions
This extension type must implement the following interface:
```php
namespace PHPStan\Reflection;
interface MethodsClassReflectionExtension
{
public function hasMethod(ClassReflection $classReflection, string $methodName): bool;
public function getMethod(ClassReflection $classReflection, string $methodName): MethodReflection;
}
```
Most likely you will also have to implement a new `MethodReflection` class:
```php
namespace PHPStan\Reflection;
interface MethodReflection
{
public function getDeclaringClass(): ClassReflection;
public function getPrototype(): self;
public function isStatic(): bool;
public function isPrivate(): bool;
public function isPublic(): bool;
public function getName(): string;
/**
* @return \PHPStan\Reflection\ParameterReflection[]
*/
public function getParameters(): array;
public function isVariadic(): bool;
public function getReturnType(): Type;
}
```
This is how you register the extension in project's PHPStan config file:
```
services:
-
class: App\PHPStan\EnumMethodsClassReflectionExtension
tags:
- phpstan.broker.methodsClassReflectionExtension
```
## Dynamic return type extensions
If the return type of a method is not always the same, but depends on an argument passed to the method,
you can specify the return type by writing and registering an extension.
Because you have to write the code with the type-resolving logic, it can be as complex as you want.
After writing the sample extension, the variable `$mergedArticle` will have the correct type:
```php
$mergedArticle = $this->entityManager->merge($article);
// $mergedArticle will have the same type as $article
```
This is the interface for dynamic return type extension:
```php
namespace PHPStan\Type;
use PhpParser\Node\Expr\MethodCall;
use PHPStan\Analyser\Scope;
use PHPStan\Reflection\MethodReflection;
interface DynamicMethodReturnTypeExtension
{
public function getClass(): string;
public function isMethodSupported(MethodReflection $methodReflection): bool;
public function getTypeFromMethodCall(MethodReflection $methodReflection, MethodCall $methodCall, Scope $scope): Type;
}
```
And this is how you'd write the extension that correctly resolves the EntityManager::merge() return type:
```php
public function getClass(): string
{
return \Doctrine\ORM\EntityManager::class;
}
public function isMethodSupported(MethodReflection $methodReflection): bool
{
return $methodReflection->getName() === 'merge';
}
public function getTypeFromMethodCall(MethodReflection $methodReflection, MethodCall $methodCall, Scope $scope): Type
{
if (count($methodCall->args) === 0) {
return \PHPStan\Reflection\ParametersAcceptorSelector::selectFromArgs(
$scope,
$methodCall->args,
$methodReflection->getVariants()
)->getReturnType();
}
$arg = $methodCall->args[0]->value;
return $scope->getType($arg);
}
```
And finally, register the extension to PHPStan in the project's config file:
```
services:
-
class: App\PHPStan\EntityManagerDynamicReturnTypeExtension
tags:
- phpstan.broker.dynamicMethodReturnTypeExtension
```
There's also an analogous functionality for:
* **static methods** using `DynamicStaticMethodReturnTypeExtension` interface
and `phpstan.broker.dynamicStaticMethodReturnTypeExtension` service tag.
* **functions** using `DynamicFunctionReturnTypeExtension` interface and `phpstan.broker.dynamicFunctionReturnTypeExtension` service tag.
## Type-specifying extensions
These extensions allow you to specify types of expressions based on certain pre-existing conditions. This is best illustrated with couple examples:
```php
if (is_int($variable)) {
// here we can be sure that $variable is integer
}
```
```php
// using PHPUnit's asserts
self::assertNotNull($variable);
// here we can be sure that $variable is not null
```
Type-specifying extension cannot have `PHPStan\Analyser\TypeSpecifier` injected in the constructor due to circular reference issue, but the extensions can implement `PHPStan\Analyser\TypeSpecifierAwareExtension` interface to obtain TypeSpecifier via a setter.
This is the interface for type-specifying extension:
```php
namespace PHPStan\Type;
use PhpParser\Node\Expr\StaticCall;
use PHPStan\Analyser\Scope;
use PHPStan\Analyser\SpecifiedTypes;
use PHPStan\Analyser\TypeSpecifierContext;
use PHPStan\Reflection\MethodReflection;
interface StaticMethodTypeSpecifyingExtension
{
public function getClass(): string;
public function isStaticMethodSupported(MethodReflection $staticMethodReflection, StaticCall $node, TypeSpecifierContext $context): bool;
public function specifyTypes(MethodReflection $staticMethodReflection, StaticCall $node, Scope $scope, TypeSpecifierContext $context): SpecifiedTypes;
}
```
And this is how you'd write the extension for the second example above:
```php
public function getClass(): string
{
return \PHPUnit\Framework\Assert::class;
}
public function isStaticMethodSupported(MethodReflection $staticMethodReflection, StaticCall $node, TypeSpecifierContext $context): bool;
{
// The $context argument tells us if we're in an if condition or not (as in this case).
return $staticMethodReflection->getName() === 'assertNotNull' && $context->null();
}
public function specifyTypes(MethodReflection $staticMethodReflection, StaticCall $node, Scope $scope, TypeSpecifierContext $context): SpecifiedTypes
{
// Assuming extension implements \PHPStan\Analyser\TypeSpecifierAwareExtension.
return $this->typeSpecifier->create($node->var, \PHPStan\Type\TypeCombinator::removeNull($scope->getType($node->var)), $context);
}
```
And finally, register the extension to PHPStan in the project's config file:
```
services:
-
class: App\PHPStan\AssertNotNullTypeSpecifyingExtension
tags:
- phpstan.typeSpecifier.staticMethodTypeSpecifyingExtension
```
There's also an analogous functionality for:
* **dynamic methods** using `MethodTypeSpecifyingExtension` interface
and `phpstan.typeSpecifier.methodTypeSpecifyingExtension` service tag.
* **functions** using `FunctionTypeSpecifyingExtension` interface and `phpstan.typeSpecifier.functionTypeSpecifyingExtension` service tag.
## Known issues
* If `include` or `require` are used in the analysed code (instead of `include_once` or `require_once`),
PHPStan will throw `Cannot redeclare class` error. Use the `_once` variants to avoid this error.
* If PHPStan crashes without outputting any error, it's quite possible that it's
because of a low memory limit set on your system. **Run PHPStan again** to read a couple of hints
what you can do to prevent the crashes.
## Code of Conduct
This project adheres to a [Contributor Code of Conduct](https://github.com/phpstan/phpstan/blob/master/CODE_OF_CONDUCT.md). By participating in this project and its community, you are expected to uphold this code.
## Contributing
Any contributions are welcome.
### Building
You can either run the whole build including linting and coding standards using
```bash
vendor/bin/phing
```
or run only tests using
```bash
vendor/bin/phing tests
```