Switch from Psalm to PHPStan

Author: BenMorel

.github/workflows/ci.yml

@@ -3,12 +3,12 @@ name: CI
 on: [push, pull_request]
 
 env:
-  PSALM_PHP_VERSION: "8.5"
+  PHPSTAN_PHP_VERSION: "8.5"
   COVERAGE_PHP_VERSION: "8.5"
 
 jobs:
-  psalm:
-    name: Psalm
+  phpstan:
+    name: PHPStan
     runs-on: ubuntu-latest
 
     steps:
@@ -18,13 +18,13 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: ${{ env.PSALM_PHP_VERSION }}
+          php-version: ${{ env.PHPSTAN_PHP_VERSION }}
 
       - name: Install composer dependencies
         uses: ramsey/composer-install@v3
 
-      - name: Run Psalm
-        run: vendor/bin/psalm --show-info=false --find-unused-psalm-suppress --no-progress
+      - name: Run PHPStan
+        run: vendor/bin/phpstan --no-progress
 
   coding-standard:
     name: Coding Standard

composer.json

@@ -15,7 +15,7 @@
   },
   "require-dev": {
     "phpunit/phpunit": "^11.0",
-    "vimeo/psalm": "6.14.3"
+    "phpstan/phpstan": "2.1.42"
   },
   "autoload": {
     "psr-4": {

phpstan.neon

@@ -0,0 +1,7 @@
+parameters:
+    level: 10
+    checkUninitializedProperties: true
+    ignoreErrors:
+        - identifier: missingType.iterableValue
+    paths:
+        - src

psalm-baseline.xml

@@ -30,9 +30,6 @@
 
 use const JSON_THROW_ON_ERROR;
 
-/**
- * @psalm-suppress MixedAssignment
- */
 final readonly class JsonMapper
 {
     private Reflector $reflector;
@@ -126,7 +123,7 @@ private function mapToObject(stdClass $jsonData, string $className): object
     {
         try {
             $reflectionClass = new ReflectionClass($className);
-        } catch (ReflectionException $e) {
+        } catch (ReflectionException $e) { // @phpstan-ignore catch.neverThrown
             throw new JsonMapperException('Invalid class name: ' . $className, $e);
         }
 
@@ -152,9 +149,8 @@ private function mapToObject(stdClass $jsonData, string $className): object
         }
 
         if ($this->onExtraProperties === OnExtraProperties::ThrowException) {
-            /** @psalm-suppress MixedAssignment, RawObjectIteration */
-            foreach ($jsonData as $jsonPropertyName => $_) {
-                /** @var string $jsonPropertyName https://github.com/vimeo/psalm/issues/9108 */
+            foreach ($jsonData as $jsonPropertyName => $_) { // @phpstan-ignore foreach.nonIterable
+                /** @var string $jsonPropertyName */
                 if (! in_array($jsonPropertyName, $consumedJsonPropertyNames, true)) {
                     throw new JsonMapperException([
                         sprintf(

psalm.xml

@@ -15,10 +15,14 @@ final class CamelCaseToSnakeCaseMapper implements NameMapper
     #[Override]
     public function mapName(string $name): string
     {
-        return preg_replace_callback(
+        $result = preg_replace_callback(
             '/[A-Z]/',
             fn (array $matches) => '_' . strtolower($matches[0]),
             $name,
         );
+
+        assert($result !== null);
+
+        return $result;
     }
 }

src/JsonMapper.php

@@ -15,10 +15,14 @@ final class SnakeCaseToCamelCaseMapper implements NameMapper
     #[Override]
     public function mapName(string $name): string
     {
-        return preg_replace_callback(
+        $result = preg_replace_callback(
             '/_([a-z])/',
             fn (array $matches) => strtoupper($matches[1]),
             $name,
         );
+
+        assert($result !== null);
+
+        return $result;
     }
 }

src/NameMapper/CamelCaseToSnakeCaseMapper.php

@@ -162,7 +162,6 @@ private function getParameterTypeFromDocComment(ReflectionParameter $parameter):
 
         $pattern = '/@param(.*)\$' . $parameter->getName() . '\W/';
 
-        /** @var list<array{string}> $matches */
         preg_match_all($pattern, $docComment, $matches, PREG_SET_ORDER);
 
         if (count($matches) === 0) {
@@ -186,6 +185,7 @@ private function getParameterTypeFromDocComment(ReflectionParameter $parameter):
         }
 
         $type = preg_replace('/(^\s+)|(\s+$)/', '', $type);
+        assert($type !== null);
 
         if ($type === '') {
             throw new JsonMapperException(sprintf(
@@ -208,6 +208,7 @@ private function getParameterTypeFromDocComment(ReflectionParameter $parameter):
 
         return $this->createUnionType(
             array_map(
+                // @phpstan-ignore argument.type
                 fn (string|array $value) => $this->convertDocCommentType($value, $parameter),
                 $parsedType,
             ),
@@ -232,6 +233,7 @@ private function convertDocCommentType(string|array $type, ReflectionParameter $
         return new ArrayType(
             $this->createUnionType(
                 array_map(
+                    // @phpstan-ignore argument.type
                     fn (string|array $type) => $this->convertDocCommentType($type, $reflectionParameter),
                     $type,
                 ),
@@ -252,7 +254,7 @@ private function getParameterTypeFromReflection(ReflectionType $type, Reflection
         if ($type instanceof ReflectionUnionType) {
             return $this->createUnionType(
                 array_map(
-                    function (ReflectionNamedType|ReflectionIntersectionType $type) use ($reflectionParameter): SimpleType|ClassType|EnumType|ArrayType {
+                    function (ReflectionNamedType|ReflectionIntersectionType $type) use ($reflectionParameter): SimpleType|ClassType|EnumType {
                         if ($type instanceof ReflectionIntersectionType) {
                             $this->throwOnIntersectionType($reflectionParameter);
                         }
@@ -375,7 +377,7 @@ private function convertNamedType(string $namedType, bool $isReflection, Reflect
             );
         }
 
-        /** @psalm-var class-string $namedType */
+        /** @var class-string $namedType */
         return new Type\ClassType($namedType);
     }
 

src/NameMapper/SnakeCaseToCamelCaseMapper.php

@@ -19,9 +19,6 @@ public function __construct(
     ) {
     }
 
-    /**
-     * @psalm-suppress ImplicitToStringCast
-     */
     #[Override]
     public function __toString(): string
     {