Type getResult() from its constant $type argument

Author: paulbalandan

docs/type-inference.md

@@ -125,6 +125,8 @@ framework declares as a bare `array` or a loose object union at the interface le
 
 - `getResultArray()`: `list<array<string, mixed>>`
 - `getResultObject()`: `list<stdClass>`
+- `getResult($type)`: a list keyed off the constant `$type`, namely `list<array<string, mixed>>` for
+  `'array'`, `list<stdClass>` for `'object'` (the default), and `list<T>` for a `class-string`.
 - `getRowArray()`: `array<string, mixed>|null`
 - `getRowObject()`: `stdClass|null`
 - `getCustomResultObject($className)`: `list<T>` when `$className` is a constant `class-string`, or a

src/Type/ResultMethodReturnTypeExtension.php

@@ -48,6 +48,7 @@ public function getClass(): string
     public function isMethodSupported(MethodReflection $methodReflection): bool
     {
         return in_array($methodReflection->getName(), [
+            'getResult',
             'getResultArray',
             'getResultObject',
             'getRowArray',
@@ -59,6 +60,7 @@ public function isMethodSupported(MethodReflection $methodReflection): bool
     public function getTypeFromMethodCall(MethodReflection $methodReflection, MethodCall $methodCall, Scope $scope): ?Type
     {
         return match ($methodReflection->getName()) {
+            'getResult'             => $this->resultType($methodCall, $scope),
             'getResultArray'        => $this->listOf(new ArrayType(new StringType(), new MixedType())),
             'getResultObject'       => $this->listOf(new ObjectType(stdClass::class)),
             'getRowArray'           => TypeCombinator::addNull(new ArrayType(new StringType(), new MixedType())),
@@ -68,6 +70,33 @@ public function getTypeFromMethodCall(MethodReflection $methodReflection, Method
         };
     }
 
+    /**
+     * Types `getResult($type)` from its constant `$type`: `'array'`, `'object'` (the default), or a
+     * class name. A non-constant `$type` leaves the framework's declared `array`.
+     */
+    private function resultType(MethodCall $methodCall, Scope $scope): ?Type
+    {
+        $args = $methodCall->getArgs();
+
+        if (! isset($args[0])) {
+            return $this->listOf(new ObjectType(stdClass::class));
+        }
+
+        $strings = $scope->getType($args[0]->value)->getConstantStrings();
+
+        if (count($strings) !== 1) {
+            return null;
+        }
+
+        $value = $strings[0]->getValue();
+
+        return match ($value) {
+            'array'  => $this->listOf(new ArrayType(new StringType(), new MixedType())),
+            'object' => $this->listOf(new ObjectType(stdClass::class)),
+            default  => $this->listOf($this->reflectionProvider->hasClass($value) ? new ObjectType($value) : new ObjectWithoutClassType()),
+        };
+    }
+
     private function customObjectType(MethodCall $methodCall, Scope $scope): Type
     {
         $args = $methodCall->getArgs();

tests/data/type-inference/database-result-methods.php

@@ -34,4 +34,13 @@ function resultAccessors(ResultInterface $result, string $dynamic): void
 
     // Already precise on the interface via a conditional @return, so the extension leaves it untouched.
     assertType('stdClass|null', $result->getRow(0));
+
+    // getResult($type) is typed from its constant $type argument.
+    assertType('list<stdClass>', $result->getResult());
+    assertType('list<stdClass>', $result->getResult('object'));
+    assertType('list<array<string, mixed>>', $result->getResult('array'));
+    assertType('list<CodeIgniter\PHPStan\Tests\Fixtures\Entity\BlogComment>', $result->getResult(BlogComment::class));
+
+    // A non-constant $type leaves the framework's declared array.
+    assertType('array', $result->getResult($dynamic));
 }